Gong Xi Fa Cai!  As many of my friends and colleagues are celebrating the New Year and welcoming in the year of the water snake, I wanted to take a minute and wish you all well.  May the New Year bring each of you prosperity, good luck and a new PSoC design.  

2012 was a fantastic year for PSoC Creator with the release of 24 new Components, numerous Component updates including MISRA compliance, Rubber-Banding, Document Manager, Starter Design templates and project datasheet generation.  Looking forward, we're planning even more new Components and exciting features for 2013.  

More Information:

Wikipedia: http://en.wikipedia.org/wiki/Chinese_New_Year

The beautiful photo was shared under a Creative Commons Free Cultural Works License by maywong_photos and can be found on Flickr.

PSoC workshops are getting really popular! Tomorrow I am headed to Cal Poly San Luis Obispo to advise some students on their PSoC projects and attend the winter career fair.

Hope your year is going well so far!

C. U. Around

Right click in a blank area of the top menu and select customize from the dropdown menu (right).

Create a new menu (below).  To add commands to the custom menu, go to the Commands tab.  Select a category and drag the command out of the dialog box and onto your custom toolbar.  

     I created one with Start Page, Add Component Item, Auto Hide All and DMA Wizard.

Design the way you think with PSoC Creator.

Benjamin Franklin's life and history is taught to every US grade school student.  With his famous electricity experiments with a kite, his inventions of bifocals and his daily schedule, Benjamin Franklin's legacy is still inspiring today.  If you're interested, you can find out more about his life and history from the links below.  I just want to share a quote from Benjamin Franklin that really resonates with the PSoC Creator team.

Tell me and I forget. Teach me and I remember. Involve me and I learn. 

- Benjamin Franklin

We would like to involve all of you in PSoC Creator.  Not just in using it but in helping us define the next generation because we realize this isn't just a Cypress tool it's your tool.  Please be a part of our discussions here and on the Cypress Developer Community.

Find out more about Benjamin Franklin:

Find a discussion of some of his most famous inventions including the lightning rod in 1753.  Did you know there was a television show by PBS about the life of Benjamin Franklin?  There is a good Wikipedia article about  Benjamin Franklin s life and a discussion of his famous kite experiment on a US History education site.

Ricky Gervais was interviewed in the Harvard Business Review (Ricky Gervais on Not Having a Real Job), if you subscribe to HBR you can read it, but anyone can listen to the 12 minute podcast. 

If your knowledge of this comedian is from the original The Office BBC TV series or his hosting episodes on the Golden Globesawards, the man on this podcast is NOT that man. And while Ricky did not specifically address what to do on your next embedded design, he did have some gems which can be applied to your project.

1) "Ask yourself 'Why am I doing this? What's the best that can happen?'" also ask "What's the worst that can happen?" Always critically examine what you are doing and why. What was a "good" idea at the start of the project or the start of the week may be a waste later, based upon the learning since.

2) "What matters is the work you've done" Take pride in your work. Don't be afraid to be recognized for it. Kinda goes without saying, though. Still.

3) "Write about what you know" was Ricky's response when asked why he did "The Office", but he also meant "write" about what other people know, as in everyone gets the office setting and situations. So on a project if your code and comments and design explanations aren't being understood, you missed your mark. Rewrite them for others, not for yourself. Especially if you don't wish to be fixing it for years.

4) "Be fair and upfront and you can't go wrong" Keep it real on the project, if you bring up a "problem" make sure you are talking about the "real" problem. If the "refresh rate" problem is more about you wanting to do the filtering design, be honest with the team.

5) "If everybody likes something no one will love it" Love comes with hate, like means it's watered down. When something is average it doesn't generate strong emotions, when something is great, it will also have its critics. But depending on the project, good and reliable might be exactly what is desired. Then again, the iPhone and iPad are not average, people love them and some do hate them.

6) "One veto and it's out" - Anyone on the team doesn't like something, it's dropped. What's left is everything great, but, of course lots of good ideas are rejected to keep the great. This again is how you rise above ordinary, and if your product is not required to be just good and reliable, you will need to reject some good ideas.

7) "Ya, probably not, though" Keep the language precise when you're discussing the project. This response by Ricky' to a question was very interesting, might lead you to wonder the next time he answers "Ya" is he really finished or if you wait long enough will he get to the point like "can't pay your salary this week".

2. Upgrading Embedded Design Firmware via USB (By Rakesh Reddy) – http://www.eetimes.com/design/other/4026877/Upgrading-Embedded-Design-Firmware-via-USB
This goes a little deeper into the embedded design with USB for those who are not satisfied with the first article above!

3. Common USB Development Mistakes – You Don’t Have To Make Them All Yourself! – (By Steve Kolokowsky and Trevor Davis) http://uk.farnell.com/images/en/ede/pdf/usb_dev_mistake.pdf
This is a very handy article for embedded designers starting off with USB

4.  USB Technology: Multi-TT Hub Goes Head-to-Head With Single-TT – (By Patrick Schmid for Tom’s Hardware) - http://www.tomshardware.com/reviews/usb-technology,677.html
Don’t go by the title. Most of us have used a USB hub at some point in our lives. This article – written back in 2003, gives a good understanding on how a USB hub works!

5. Increase the USB performance of your handset design (By Steve Kolokowsky) - http://www.eetimes.com/design/other/4016183/Increase-the-USB-performance-in-your-handset-design?pageNumber=1
Now that 90% of world’s handset devices (>1.3Billion handsets sold every year) have a USB port, most popularly used for charging and data transfer – this article written in 2006 is very much ahead of its time.

6. Making USB Flash Drives Secure (By Anant Jhawar)  - http://embeddeddsp.embedded.com/columns/technicalinsights/225402174?printable=true
Great read on how the most common USB device around (the flash drives / USB sticks / thumb drives – or whatever you call them J ) can be made more scure

8. USB3.0 – The Next-Generation Interconnect (By Ashwini Govindaraman)
http://electronicdesign.com/article/digital/usb_3_0_the_next_generation_interconnect.aspx
Good article on some of the basics of USB3.0

I'm writing after a long hiatus! Feels like a first entry. Need to keep this moving at a more constant rate. Thank you all for being patient!!

PSoC® Creator  2.2 is now officially available for download! This release adds new Components, enhancements for Component distribution and the ability to generate custom project datasheets.

New Components include a Digital Utility Pack with five new Components and PWM-based Temperature Sensor Interface.  There are now over 80 pre-verified, production-ready Components available for your PSoC Design.  We've improved Component distribution with easy import and export tools to simplify the sharing of PSoC Creator Components.  Generate a complete datasheet for your specific PSoC design project without creating a new component library.  

New Features:

• Additional Binding Error Symbols

• Component Distribution (Import/Export)

• Datapath Editor Enhancements

• MISRA Support

• Peripheral Register Debug in IDEs

• Project Datasheet Generation

• Variable Vdda New Parameter

New Components:

• Basic Counter

• D Flip Flop w/ Enable

• Digital Comparator

• Digital Constant

• Edge Detector

• Frequency Divider

• Pulse Converter

• SR Flip Flop

• TMP05/06

• Toggle Flip Flop

Read more about the PSoC Creator 2.2 release in the Release Notes.

Design the way you think with PSoC Creator.       

1/8/2012: The MHz ECO Clock Wizard Enhancements were removed from the PSoC Creator 2.2 features.  Look for these enhancements in a future 2013 release.

That is:

forever{

   if( MSBit == 1) toggle some bits;

   circular rotate left

}

This implementation has the problem that if the register value is zero, it remains zero.  This means for an 8 bit register, you get pseudo random values between 1 and 255.

 Instead I changed the process so that the bits are toggled  if the MSBit is 0.

forever{

   if( MSBit != 1) toggle some bits;

   circular rotate left

}

It can be implements with two of the datapath registers

 A0 = (A0 ^ D) <<1 (so conneted  to si)

  A0 = A0 <<1 (so connected to si)

Add two more states of A0=0 and you have a fix is case the register somehow gets a ff value.

Gawd I love datapaths!

Now the dead value is all ones and the PSoC logic starts up logic low. So for an 8 bit register, you get random values between 0 and 254.  This is nicer for density signal generation.  You do not have to initialize this hardware as it will start up with its initial values.

The PSoC Creator team is continually working to make our tools easier to use and to let our customers have the best experience possible on PSoC.  As part of that mission, we've been working on continually updating our component datasheets into Chinese and Japanese.  In the future, we're planning on service packs to add the datasheets natively into the Creator build where they will open based on your host PC's native language setting.  Until we're 100% there, you can access the datasheets directly from each component's web page.

Within Creator Today, you have three ways to get to Chinese or Japanese Datasheets.

• Right clicking on a component will bring up a menu with Open Component Web Page.  You'll find the Chinese and Japanese language datasheets with the documentation.
• Help -> Documentation -> Japanese Language -> Component Datasheets will open a list of all of the datasheets translated into Japanese.
• If you're in the Document Manager, selecting any Component Datasheet will bring up the Component Web pages with the associated translated datasheets.

Here is the link (bookmark it!): http://www.cypress.com/go/programming

Perhaps most importantly we maintain a table of production programming solutions for all parts. Here is a snapshot summary of that information (there is more detail on the web).

As we extend the list of supported programmer tools we ll post a message to this forum and update the table on the web so you can always have an accurate and up-to-date record of your PSoC programming choices.

Happy Programming!

can get Cypress to have a limited edition built.  Your help is appreciated.

We are in the midst of our freesoc/Arduino Shield contest and still accepting entries. For more information visit www.freesoc.net .

I'll be at MIT next week with Dave Van Ess, Mike Daly and Greg Landry (all Cypress employees) co-teaching a PSoC short course.

We will have a guest lecture by Prof. Andrzej Rucinski on how PSoC is an integral part of the Internet of Things (IoT) infrastructure as well.

Until Then,

C. U. A.round

Do you have something you would like to show?

Do you have something you would like to show and will be in San Jose

Do you have a couple of friend that thin k they can beat our Engineers in a Challenge?

Is there some topic you would like to see?

Lets us know and we will try to accommodate you.

Watching a brief walkthrough video can be a big help in conquering the PSoC Designer learning curve. Join Ganesh Raja and see how easy it is to build your first project:

http://www.cypress.com/?rID=70468

The upgrade program for the CY8CKIT-001 and CY8CKIT-010 to PSoC 5LP silicon will be coming in the first weeks of January. Look for an announcement at that time.  

Our hearts go out to those in Connecticut who are dealing with such a senseless tragedy and for any parents trying to raise children in a random vulnerable world full of risks.

 A person that loses their parents is an orphan.  Someone that loses a spouse is a widow or a widower.  I know of no name for someone that loses a child.  I think that is because it is an event to horrid to contemplate finding a name.  I know I don't want to do it.

This just brings to light that our serious problems really are the ones we are not paid to solve.

No matter how slight the risks, some will get struck by lightening. It is a fear all parents share.  Just don t let the fear rule your life and keep you from raising healthy, inquisitive, risk taking children.  (If they are anything like me. you will have to worry about the pyrotechnic teen years.)  Remember some will also win the lotto and maybe your child will change the world.

The PSoC 3 (CY8CKIT-001, CY8CKIT-003) upgrade program will end January 4^th, 2013.  I would like to thank everyone who participated over the last two years for trying out our new silicon. I hope you had an excellent upgrade experience. If you haven't yet had a chance to upgrade your system, you still have a few days.  We are taking upgrade requests through the end of the day on January 4^th. You just need to fill out a short form on the PSoC Kit Upgrade Program website.

The team here at Cypress wants you to have the best experience possible with PSoC.  That's why we offer free kit upgrades to production silicon or new silicon (look for a PSoC 5 to PSoC 5LP upgrade program coming soon).  We strongly believe being an early adopter shouldn't penalize you.  We will continue to offer these kit upgrades to production silicon and new key silicon. The PSoC 3 kit upgrade program was highly successful with just under a thousand total kits upgraded over the last two years and we hope that all PSoC 5 customers will use the kit upgrade program to try out the PSoC 5LP.  

Although I wish everyone could come visit us in our Seattle office where we make PSoC, your programmable solution on a chip, it's a bit cold and grey this time of year.  Instead, virtually visit us at PSoC World 2012 on Dec 12 & 13.  I think you'll really enjoy the technical sessions, inspiring keynotes and a chance to chat with me and the whole PSoC team all from the comfort of your home or desk.  I'm most looking forward to the PSoC pannel discussion between several of our customers, a university professor and a PSoC expert from Arrow all moderated by Dan Byers, Senior Director of World Wide FAEs.  I think the discussion will be lively to say the least.

Tom Lantzsch, the EVP of Strategy for ARM, is discussing intelligence everywhere and the pervasive nature both of ARM processors and the fundamental shift in products for increasing technology at lower and less expensive price points.  He also brings up some great thought provoking concepts on energy conservation and low power.

If you're an engineer who likes wine, you need to check out Cypress's CEO, T.J. Rodgers' keynote on the science and technology he's introducing to wine-making in his vineyard near the mountains of Santa Cruz, California and at the University of California at Davis.  T.J. is an engineer's engineer and brings measurement, a knowledge of organic chemistry and fun electronics to everything he does and wine is no exception. 

If you need more convincing, check out the following:

• Watch the Sneak Peak with real session content
• Take a look at the Agenda
• Read the personal invitation John Weil, Director of PSoC Marketing and Applications, sent to the ARM community
• Meet Alan Hawse, Executive Vice President of Software, in his PSoC Creator Commercial

Important specifications:

Supply Voltage: 5V

Accuracy: +/-0.25%

Total error band: +/-2% FSS

Sensor Operation:

This sensor has an amplified and temperature compensated output and is driven by a voltage supply. The output curve and equation are shown below.

Design:

The design is very simple as both amplification and temperature compensation are done within PSoC.  Resolution should be 1/1000th of full scale, hence a 10-bit ADC is required. The sensor output voltage goes to 90% of the supply voltage, so the ADC range should be vssa vdda. The ADC should operate with the rail-rail buffer enabled. Sensor output is ratiometric and the ADC reference should be Vdda/4.

PSoC Top Design and ADC configuration:

Although not as many analog resources are required when interfacing a pressure sensor with an amplified output, integrating a sensor with other PSoC features such as capsense, segment LCD drive and communication protocols, etc, will lower overall system costs.

Conclusion:

PSoC3 and PSoC 5LP can sense pressure accurately while reducing BOM cost and board space by integrating the analog front-end, ADC, reference and MCU. PSoC ADC inputs can be multiplexed with many inputs (limited only by the GPIO count) allowing interfacing to multiple pressure sensors or other analog sensors. The PSoC Creator design environment makes it easier for you to design and debug, reducing the design time and your time to market.

By Praveen Sekar

Supply current = 1.5 mA

Pressure Range:  0 -15 psi (Gage)

Sensitivity (max): 10 mV / psi

Sensitivity (min): 5 mV / psi

Temp error - span (max): 0.5 % FSS

Offset (max): 2 mV

Temperature error - offset: 0.5% FSS

Specified temp range: -40 to 125 °C

Bridge resistance (max): 6.4 k (50°C)

Accuracy: +/-0.1 % FSS BFSL

Sensor Operation:

The sensor is a piezo-resistive sensor excited by a current and has an output voltage proportional to the pressure and the current. The output voltage has a 50% tolerance and the sensor provides a gain set resistor to calibrate it to 1%. When the sensor is excited by proper current excitation levels specified in the datasheet, the temperature coefficient of span and offset will cause only a very small error in the final measurement (temperature compensated).

Design:

The design requires an excitation current of 1.5mA and an ADC to measure the output voltage. With a bridge resistance of 6.4k (max) and excitation current of 1.5mA (current level prescribed in the datasheet for proper temperature compensation), the load voltage of the current source is 9.6V. This means PSoC IDAC cannot directly be used for supplying bridge current because of very high load voltage. To limit external components and get maximum value out of PSoC we can use circuit below.

By controlling the V_GS of this circuit, the I_D can be controlled. V_GS is controlled by changing the current of the sinking IDAC. R_B ensures the IDAC output voltage is within compliance and optimum. The current sense resistor (0.1%), R_SENS,aids in setting the current to 1.5mA. The voltage across R_SENS is read by PSoC ADC (0.2%) and the IDAC current is adjusted until I_D becomes 1.5mA. With this circuit, we can ensure that the current is accurate to 0.3%. A current accuracy of 2% is the requirement so the temperature error due to offset and span are within datasheet limits.

Sensor Common mode output voltage:

With this design the sensor common mode output voltage is given by;

(1.5 * 6.4)/2 + 0.150 /2 + (1.5mA * 0.05)/2 = 4.8 + 0.075 + 0.0375 = 4.91 V

Here, 1.5mA is the sensor current, 6.4k is the max bridge resistance and 0.150 V is the maximum span, 0.05 is the sense resistance.

The sensor common mode voltage is very high to directly feed into PSoC. The ADC with input buffer can accommodate only to within 200 mV of Vdda. The ADC without buffer can t be used because it has low input impedance. The PGA can allow input voltage all the way to the voltage rail, but we ll be limiting the design to supplies with very strict tolerance levels. This is not desirable as various designers might want flexibility in their power supply design (at least support 5% supplies).

Hence to lower the common mode voltage we can use a charge pump that generates a negative voltage. The generated voltage is about -3V using a negative charge pump. The ripple voltage (of <10%) on the charge pump output doesn t have a major effect as long as we set the ADC input sampling frequency as an integral multiple of the ripple frequency (the charge pump clock frequency).

ADC input range:

The sensor span is 150mV (max). The ADC input range should be > +/- 0.256V.  

Resolution:

Resolution required in 1/1000^th of full scale. At minimum span of 75mV, we require 75uV of voltage resolution. At 15-bit level, the ADC resolution is 64uV. With a gain of 4, the ADC resolution is < 16uV.

At +/-1.024V range, we require 15-bit resolution

At +/-0.256V range, we require 13-bit resolution

Reference:

This measurement requires an absolute reference. The final pressure accuracy depends on the reference accuracy, therefore the internal 1.024 V reference is a good choice.

The ADC has four channels:

0.  Sense resistance channel: This channel is used to set the current to 1.5mA

1.  Sensor Channel: Senses the sensor output

2, 3.  Calibration channels: Measures the gain set resistance for calibration

The IDAC has two channels:

1. Passes current through the calibration resistance

2. Passes current through the sensor

The ADC configuration for the pressure sensing channel is shown below.

Pressure Equation:

The pressure is computed from the measured voltage using the following equation.

P = A* (V_o / S_i) * P_r

P Pressure (in psi)

V₀ Bridge output voltage in mV

S_i Span of pressure sensor output in mV

P_r Rated Pressure (in psi)

A I/1.5. I is the actual current flowing into the pressure sensor

Calibrations required:

Span Calibration:

The Span of the pressure sensor is calibrated using the gain set resistance provided in the sensor. Using the gain set resistance, r, the span can be calibrated. The gain set resistance is trimmed such that when it s used in conjunction with a differential amplifier, it ll give a 2V span. Working the equations back, you can find that the gain set resistance.

r = (2 * Rf * Si)/ (So Si)

Here, Rf is feedback resistor of the differential amplifier, Si is the span of the pressure sensor output (differential amplifier input) and So is the span at the differential amplifier output. By looking at the datasheet of the part, Rf and So can be found. For MEAS 1210, Rf = 100k and S₀ = 2V.  By measuring r, we can find the span,

S_i = 2/(1 + (200/r))

Performance measures:

Offset:

The sensor has a 2mV offset (max). This can be calibrated out to zero.

Span error:

The gain set resistor can provide an interchangeability accuracy of 1%. In addition, the gain set resistor can be found with 0.1% accuracy only (limited by calibration resistor accuracy. If the calibration resistor is very accurate (0.01%) or calibrated, then the span error will be 1%.

Temperature Error offset:

This has a maximum error of 0.5% FS. This is 0.075 psi.

Temperature Error span:

This has a maximum error of 0.5% FS. This is 0.075psi.

Pressure non-linearity + hysteresis:

Together they contribute 0.15% FS. This is 0.022 psi.

Signal Chain:

Offset error:

The offset error of PSoC ADC is <100uV, which can be cancelled by Correlated Double Sampling (CDS).

Offset drift:

Offset drift of PSoC is 0.55uV/°C. At 50°C, this is 11uV. It is 1/7^th of minimum resolution (0.015psi). It can be cancelled by Correlated Double Sampling (CDS).

Gain error:

PSoC ADC s calibrated accuracy is 0.2%. There are 2 measurements, 1 voltage measurement and 1 current measurement (current set to 1.5mA). This can contribute to 0.4% error in total.

Gain drift:

Drift is 50 ppm/°C. For 25°C change, it ll be 0.125%.

List of all errors:

PSoC Value:

Apart from integrating the analog front end, ADC, 0.1% precision reference, Op-Amp, IDAC and the MCU and providing a separate channel for accurate temperature measurement, PSoC can integrate miscellaneous features suchascapsense, segment LCD drive and communications protocols. Designing with PSoC creator reduces the design time considerably. The BOM cost and board size can also be significantly reduced.

In the next part we ll see how to interface unamplified compensated pressure sensor with PSoC3.

By Praveen Sekar

www.cypress.com/go/programming

Many customers choose to purchase PSoC devices through a Cypress partnered distributor. These distributors will often support programming services for customers. Customers will be able to purchase devices and have those devices programmed prior to delivery or manufacturing. Since our distributors provide these programming services we have ensured that we are working with mutual third party programming companies in order to ensure timely support for our customers. Distributors often support multiple programming vendors for their programming services. We work to ensure that we have qualified at least one programming vendor for each of the Cypress distributors.

www.cypress.com/?app=distiInventory&source=buy

If one has questions or requires additional device support please file a tech support case so that your request can be expedited.

www.cypress.com/go/support

www.cypress.com/go/programming

Clicking the link above will take you to a page detailing the software and hardware you need to program your PSoC. You'll also find programming specifications and a list of our 3^rd party programming vendors. In short, it's everything you need to handle programming from your first prototype to high volume manufacturing.

Supply voltage = 5V

Pressure Range:  0 -15 psi (Gage)

Sensitivity (max): 6.9 mV / psi (25°C)

Sensitivity (min): 3.3 mV / psi (25°C)

Temp Coefficient of sensitivity (max): -3.8 %

Offset: 35.6 mV (50°C)

Temperature coefficient of offset: 1.5%

Specified temp range: -40 to 125 °C

Bridge resistance (max): 5.9 k (50°C)

Accuracy: +/-0.25 % FSS BFSL

Sensor operation:

This type of pressure sensor is a piezo-resistive sensor (Wheatstone s bridge) driven by a voltage supply. The bridge output voltage is directly proportional to the applied pressure and the supply voltage. The primary sources of error to be factored in while designing with this type of sensor is the sensor offset error, span error and temperature coefficient of span and offset (since the sensor is temperature uncompensated, temperature coefficient of span and offset play a major role in the final error).

Design:

The design parameters of concern are the ADC resolution, input range and reference.

ADC input range:

This parameter is dependent on the maximum voltage output, V₀, from the pressure sensor. At 5V supply and using the maximum offset and sensitivity possible, we get;

V₀ (max) = 6.9 * 15 + 35.6 = 139.1 mV

ADC input range should be greater than +/-0.256 V.

Resolution:

1/1000^th of the full scale resolution is sufficient in pressure sensing applications.

Pressure resolution = 15 psi/1000 = 0.015 psi

Voltage resolution = 49.543 mV/1000 = 49.543uV

This requires a 16-bit ADC in +/-1.024V range or 14-bit ADC in +/-0.256V range.

Reference:

A ratiometric reference should be used in this case. Hence PSoC reference should be configured for internal vdda/4 , where vdda = 5 volts.

PSoC Creator Top Design:

The ADC has three channels, one for sensing pressure and the other two used for temperature measurement. The RTD temperature is measured as described in AN70698.  ADC configuration for the pressure sensing channel is shown below.

Note that +/-Vref/4 range can also be used for this configuration in 14-bit mode.

Pressure Equation:

From the measured ADC voltage, the pressure is calculated from the equation below;

P = (V_o / S) * P_r

P Pressure (in psi)

V₀ Bridge output voltage in mV

S Span in mV

P_r Rated Pressure (in psi)

Calibrations required:

Room Temperature calibration:

Since span has a very high tolerance, we have to calibrate span before using it. Pressure sensor offset should also be calibrated before use.

Offset Calibration:

Offset of the pressure sensor has to be corrected by giving a zero pressure input and measuring the ADC output voltage, V_off.

V_off  = V_offp + V_offs

V_offp Pressure sensor offset

V_offs signal chain offset

Span/Gain Calibration:

The span of the pressure sensor is calibrated by applying a full scale pressure input to the pressure sensor and measuring the ADC output voltage, V_fs.

S = V_fs

(Where S is the Span)

By doing span calibration we are calibrating both the span error of the sensor and gain error of the ADC.

Temperature calibration:

Both the pressure sensor offset and span varies with temperature and they have to be calibrated. But the sensor datasheet doesn t provide information on the span or offset calibration. It provides only the limits of the error. If the characteristic curve is found by experiment, we can correct for both span and offset temperature coefficient accurately.

List of all errors:

*Note:  Assumes calibration source has zero error.

ADC INL and the sensor non-linearity are the only factors that can t be calibrated and will affect the final measurement.

PSoC Value:

Apart from integrating the analog front end, ADC and the MCU, providing a separate channel for accurate temperature measurement, PSoC can integrate miscellaneous features suchascapsense, segment LCD drive and communications protocols. Designing with PSoC creator can reduce the design time considerably. The BOM cost and board size can also be significantly reduced.

In the next part we ll see how to interface unamplified compensated pressure sensor with PSoC3.

By Praveen Sekar

Well on December 12^th Cypress will be having the first ever, virtual design conference.  IT would be worth your time.  You may have something more urgent to do but I bet that in a couple of years, you won t remember why.

Of the 400,000 people that went to Woodstock, I have personally met 2 million of them.  I guess they wanted to go to Woodstock but more urgent just came up.  Regret is a pretty powerful thing thay woul cause so many proplr to lie.

Well think of PSoC World as your cultural defining event and don t regret not going.  Maybe we should call it PSToCK, a worldwide day of peace, love, and configurability.

Peace Dude!  Peace SoC.

http://www.psocworld.com/

See you there!

In this four part series, piezo-resistive pressure sensing basics and the PSoC circuits for three types of pressure sensors will be examined. The first part covers piezo-resistive pressure sensor basics and introduces three categories of pressure sensors

Piezo-resistive Pressure sensor basics

 A piezo resistive pressure sensor has a silicon diaphragm whose resistance depends on its tension. The diaphragm undergoes tension whenever there is a pressure. It can be modelled by a Wheatstone s bridge where all the resistors change with pressure. When pressure is applied to the diaphragm, resistance of the two arms (diametrically opposite to each other) increases and the resistance of the other two arms decreases.

 Pressure sensor equations

 The change in resistance can be converted to voltage by voltage or current excitation. The equations involved in voltage and current excitation are shown below.

Voltage Excitation Mode:

In this case, the Wheatstone s bridge is excited by a voltage. Span is defined as the bridge output voltage for rated pressure (full pressure). Span( S) is given by

S = V * R/R

R Change in resistance for rated pressure

R - Bridge resistance

V Excitation voltage

R = P * P_s

P Rated Pressure

P_s Pressure sensitivity (Change in resistance for unit change in pressure)

P_s = R * k

k - Normalized pressure sensitivity i.e. Pressure sensitivity for 1ohm resistor

S = V * P * k

Span is independent of bridge resistance. The temperature coefficient of span primarily results from the temperature coefficient of pressure sensitivity which is dependent on the diaphragm material.

Current excitation:

In this case, the bridge is excited by a current source. In this case span is given by,

S = I * R * P * k

Where I is the excitation current.

In this case, the span depends on the current source and bridge resistance.  

The temperature coefficient of span results from the temperature coefficient of resistance and the temperature coefficient of pressure sensitivity.  By proper design, the two can be made close to each other. Hence current excited pressure sensors have the design advantage of tweaking the process parameters so as to reduce the effect of temperature on span.

Pressure sensor types

The pressure sensor span is generally around 50-150mV. Depending on whether the pressure sensor output is amplified and on whether the pressure sensor is compensated for temperature variations of span and offset, we can have the following categories of pressure sensors

1. Unamplified uncompensated pressure sensors
2. Unamplified compensated pressure sensors
3. Amplified pressure sensors/transmitters.

The next three parts explains interfacing each type of pressure sensor with PSoC and the system performance measures.

By Praveen Sekar

 Well the doctors have developed a vaccine for pneumonia and sure enough people don t die of it anymore.  It turns out they now die of really really bad bronchitis.

 Now that progress.  But at least the deaths from pneumonia are down.

 ps  Wear a dust mask!

This is a great opportunity to take a short break from finals and attend the virtual show of shows.

You can register by clicking here: PSoC World

See you there - there will be a few academic goodies on the show.

Until then,

C. U. A.round

This is a great opportunity to take a short break from finals and attend the virtual show of shows.

You can register by clicking here: PSoC World

See you there - there will be a few academic goodies on the show.

Until then,

C. U. A.round

Anyway, it is impossible for your microcontroller to always have every serial interface that may come along.  For example, I read about a string of 50 Christmas lights that had red, green, and blue LEDs in each bulb and here comes the best part, each bulb is addressable.  Yes, you can control each individual bulb for color and intensity, four bits for each color (red, green, and blue) and 8 bits for intensity.  Of course the string of lights came with its own controller that could generate 12 different patterns, but I wanted to create my own patterns.  With a little Google searching I found that someone had already hacked the asynchronous protocol and bit-banged an IO port to control the lights with some microcontroller.  Nobody had actually created hardware to make this easier or less CPU intensive, you know why? Because nobody else used a PSoC3 or PSoC5 with their powerful UDBs!  Yes a PSoC3/5 can bit bang with the best of them, but why bother when you have extremely flexible hardware, plus bit banging is so 90's. 

The protocol was a 26-bit packet with one start and three stop bits. Each data bit was divided into three 10uS periods.  The first period is always low, the second period was low if the data was a 1 and high if the data bit was a 0 .  The last period is always high.  See images below for bit and packet formats.

The packet format is pretty straight forward with the address, brightness level and three colors packed into 26 bits.  See figure below.

I had a choice, be lazy and use a 32-bit wide shifter or use a single 8-bit wide shifter with a slightly more complicated state machine. The 32-bit wide implementation would be easier but would be a bit wasteful in hardware.  The 8-bit wide implementation would take a bit longer, but much more efficient. I choose to go with the 8-bit wide design.  One other nice feature in the UDBs, is that you can create two 4 byte FIFOs for data flowing into or out of an interface.  This turned out to be perfect since it took 4 bytes to transfer the full 26-bit packet.

The string of lights is 50 bulbs long and if you want to update all the bulbs at one time, it would take 200 bytes (50 bulbs * 4 bytes per packet). Since you don t want the processor to just sit and wait for an interface to move data, DMA is the perfect solution. This way I was able to update the entire string using DMA with almost no CPU overhead!  Where the other guys are wasting their CPU cycles toggling bits, the CPU in the PSoC could concentrate on generating cool interactive patterns, converting DMX commands to the light string format, or any other task.  What is even better, I could implement 8 of these interfaces in a single PSoC3 or PSoC5 at the same time.  

Making this interface into a PSoC Creator component, provides a way to setup all the hardware and DMA with a single start command as with all Creator components.  More APIs are added to generate cool lighting patters.  The video below is an example of version 1.0 controlling three strings of light on my house.

This second video shows four strings on the floor in our lunch room.

This third video demonstrates yet another use for the lights.

Just think of the possibilities interfacing a string of lights to anything that can be measured with a PSoC!

Here are a few other images of the actual box the string came in, the string that I modified, my interface board, and a close up view of one of the bulbs.

Stay tuned for an upcoming video with the details of what it took to make the lighting component and how easy it is to interface the string with the Cypress PSoC3 First Touch Kit.

Mark Hastings

I2C, I2S, LIN, SM Bus, SPDIF, SPI, UART, Counters, CRC generator, Glitch filter, Quadrature Decoder, Shift register, Timer, Logic gates, Flops, Digital multiplexers and de-multiplexers, control and status registers, etc. 

You get the picture, but what is currently in the library is by no means the limit of what can be created.  Recently I sent an email to our application and field application engineers and asked what they had created with UDBs.  Here is a list of some of the components people have created with PSoC UDBs.

• 60Hz Grid Lock PLL
• Numerically Controlled Oscillator (Used for DDS)
• Forward Error Correction (FEC) decoder
• No clock stretch I2C slave
• Simple components (8bit adder, PWM, digital compares etc )
• Complex Counters 
• ADC mux sequencers
• Holiday Light controller
• Square root calculator
• First order IIR filter
• Hardware state machines
• Delta sigma modulator
• UDB discrete Fourier transform
• Byte packer (sticks two 12-bit values into 3 bytes for RF transmission)
• 7-Segment Display controller
• Remote control servo controller
• Manchester Encoder/Decoder
• 1-Wire communication interface
• ClipDetect,  Monitors 16-bit audio and over rides output if value exceeds a certain limit.
• Audioclkgen,  Creates a factional N reference for the on-chip PLL.  Used in digital audio designs.

Notice that this list contains some pretty weird stuff that you would never find standard in any microcontroller.  You won t even find most this stuff in the standard PSoC Creator library, yet!  The point is, that it doesn t matter.  You can create your own  custom interface or component, that makes your project unique without adding extra external glue logic or a CPLD.

Cypress does have a Community Components page where people can post any component they have created.  Unfortunately it has been a very well kept secret until now.  Do yourself a favor and check out the Community Components page.

Also, if you want to get more training on creating components, read the app notes I mentioned above or look at the community components guidelines on this this page.

If you have created a cool component (or even a weird one), don t be afraid to share it with the Cypress community for your 15 minutes of fame. 

By Mark Hastings

http://www.cypress.com/?rID=72148

Register today. We are also going to have some of our premier design partners exhibit in a state of the art virtual trade show environment.

Register today: http://www.psocworld.com

The same is with PSoC World.  It will have something for the beginners and yet there will be something for even the most experienced PSoC Zealot.

PSoC World is scheduled for December 12^th in the Americas and December 13^th in the Not Americas.  It will be 24 hours of continuous PSoC.  There will be region specific sessions.

So come to the Show of Shows without ever leaving your desk.  No fuss with travel.  No having to go through the Back scatter X-ray machine that the TSA tells us is safe, but who really knows.  Take off your shoes only if you want to.

I have been doing PSoC for 12 years now and I am looking forward to seeing many different solutions.  I am sure I will learn something new.  I hope to see you there.

I have already registered (http://psocworld.com ) (Thanks JF!)  and I found it extremely easy to register.  They asked very few questions and they didn t ask any information about design cycles or the predicted yearly consumption of parts in the next 30 to 90 days. (I hate that!) So give it a try.

http://www.engineeringtv.com/video/Cypress-Semiconductor-PSoC-T-56

If you are a Cypress design partner and you would like to show case your PSoC based products in our show contact us at designpartners@cypress.com

http://www.cypress.com/go/psoctoday

All five webisodes are now available, covering auto-routing, dynamic reconfiguration, the VoltageSequencer user module and much more!

 0, 1, 3, 2, 6, 7, 5, 4, 12, 13, 15, 14, 10, 11, 9, 8, 24,25, 27, 26, 30, 31, 29, 28, 20, 21, 23, 22, 18, 19, 17, 16, 48, 49, 51, 50, 54, 55, 53, 52, 60, 61, 63, 62, 58, 59, 57, 56, 40, 32

When I finally get round to building one of these again, I'm sure that PSoC will be a fantastic supervisory controller, with its flexible analog and programmable digital hardware.  This will allow the monitoring and calculation of temperatures, power dissipation levels, overload and operating points, built-in timers, power quality analysis, earth loop impedance measurement... so many useful things a great audio power amp might need.  If any of you out there are doing or have done any power amplifier supervisory stuff, check out PSoC3, and ping me if you have any questions.

After I've got over the shock of the beginning of the new quarter, my next published Filter Wizard article will likely be on circuits that generate voltage gain using only pure lumped resistors and capacitors.  Useful?  Don't know, but certainly unexpected!  best / Kendall

It used to be with creating host applications for a computer, you only needed to create one application for Windows. In today's world, operating systems such as Mac OS X and Linux are growing in popularity. Additionally, mobile devices running Android are increasing in numbers with the continuous  production of smart phones and tablets. With so many different operating systems available, the need for cross platform functionality is ever so more important.

What if I told you there was a way to develop a PSoC 3 or PSoC 5 application to easily stream general data across USB and provide the foundation for cross platform functionality?  Using the Human Interface Device (HID) class makes this possible. Yes, the same class that is used for mice and keyboards is breaking free from the stereotype that it is limited to a device that requires some form of human interface, such as a button press, to function.

The truth is that the HID protocol provides the perfect foundation to shuttle data back and forth between a PSoC and computer, in applications where high speed data transfer is not required. Best of all is that implementing a generic HID on PSoC is easy to do and creating Graphical User Interfaces (GUIs) on various operating systems such as Windows, Mac OS X, and Linux is fairly straightforward.  AN82072: PSoC 3 / PSoC 5 USB General Data Transfer with Standard OS Drivers will guide you through all the steps required to do so. You will have your PSoC streaming data to a host operating system of your choice in no time! 

You can download this application note from the following link.
AN82072 - PSoC® 3 / PSoC 5 USB General Data Transfer with Standard OS Drivers

By Robert Murphy

• Children s stories
• Navy stories
• Engineering stories

Children s stories start with Once upon a time and end up happily ever after.

Navy stories start with Now this ain t no sh*t and end up with a big laugh.

Engineering stories start with All you have to do is and they never end up well.

Never!

1.       SMBus and PMBus

These complete Cypress power supervision portfolio for PSoC 3 and PSoC 5, by adding SMBus and PMBus slave communication capability to PSoC. Learn more about PSoC Power Supervision solution at http://www.cypress.com/go/PowerSupervision.

2.       Debouncer

This is probably going to be the most-used component out of all six new releases because it is the easiest and best way to debounce and edge-detect switch inputs to your system, without using your CPU.

3.        Glitch Filter

The hardware glitch filter removes unwanted pulses from a digital signal, and is a frequently used function in digital designs. The Glitch Filter v2.0 is a complete re-design from its previous version which was available as a PSoC Creator concept component.

For more information on switch-debouncing and glitch-filtering, see AN60024.

4.       RTD Calculator

5.       Thermistor Calculator

6.       Thermocouple Calculator

These three new components add easy-to-implement temperature-sensing capability to PSoC Creator s component library. Find out more about temperature-sensing with PSoC 3 and PSoC 5 through the suite of application notes available:

·         AN70698 - Temperature Measurement with RTDs

·         AN66477 - Temperature Measurement with Thermistor

·         AN75511 - Temperature Measurement with Thermocouples

In addition, you may be interested in:

·         AN60590 - Temperature Measurement Using Diode

·         AN65977 - Creating an Interface to a TMP05/TMP06 Digital Temperature Sensor

CP4 also provides an update to the I2C Master/Multi-Master/Slave component, with the addition of an I2C bus multiplexing feature, besides for some minor tweaks.

I have already installed CP4 on my system especially for the debouncer. Many of you may want one or more of these new components, or the more robust I2C. To get all of these, please download Component Pack 4.

http://www.cypress.com/?rID=70468

Also, don't miss episode 2 of PSoC Today's continuing series on PSoC Designer 5.3:

http://www.cypress.com/?rID=70509

The Constants component is a very simple way to display constants used by the firmware on the schematic.  Also this allows you to change firmware parameters without changing actual source code.  I have created an example component that allows the user to assigns names and values to up to four constants.  The component consists of just a symbol and a header file. Below is what the component would look like on the schematic.  The four constants have already been assigned names, DEBUG, LOOP, DELAY, and COUNT, as well as values.

Figure 1 Example Project Constants Component

The configuration is very simple.  The user simply assigns a name and value.  The header file is automatically generated.  The constants defined below will have the instance name pre-pended on the name.  For example, the LOOP constant name will be MyConstants_LOOP .

Figure 2 Configuration dialog of Project Constants Component

The generated header file would look like this using the configuration in Figure 2.

 #defineMyConstants_DEBUG   0

#defineMyConstants_LOOP   100

#defineMyConstants_DELAY   95

#defineMyConstants_COUNT   5

 

The constants can then be used throughout the firmware, just by including the MyConstants.h header file.  Below is an example of a code snippet that makes use of the constants provided in MyConstants.h.

 for(i = 0; i < MyConstants_LOOP; i++)

{

      LCD_Position(1,5);  
   
      LCD_PrintHexUint8(i);

      CyDelay(MyConstants_DELAY);

}

   

The same concept could be used for user created components for a specific application. For example a project phase component that displays on the schematic whether the project is in the release or debug phase.  The header file would contain the #define statements for the different mode.

Figure 3 Project Phase Component

Other similar components can easily be generated by the user, with just some simple basic knowledge of how to create components. For example if you wanted a waveform generator to change the waveform without changing code.

Figure 4 Application Mode Example

The header file would contain the following:

 #defineAppMode_Mode     2

#defineAppMode_SINE     0

#defineAppMode_SQUARE   1

#defineAppMode_TRIANGLE 2

 

The firmware would look at the AppMode_Mode constant to determine which waveform to generate, requiring no code changes.

This is just one simple trick to make a project more flexible and easier to change its operation without editing code.  It is also a good way to demo an application to a customer.  The user can then try different operations without editing code.  The MyConst component is generic and can be used with any project.  The ProjectPhase and AppMode components can easily be created by the user in a matter of minutes.

By Mark Hastings

http://www.cypress.com/go/psoctoday

or go straight to the video at:

http://www.youtube.com/watch?v=ChNLMlbvh0A&feature=share&list=UUOPwgpx4mNwPULlfdCn1xiQ

 http://www.youtube.com/watch?v=yYQ5ZZIbn_Q&feature=related

 I used to design medical equipment and it was pretty gross the kind of stuff you would find in crevices around the keys.  I guess I will be paying attention to the staff at my doctor s the next time I come in for a checkup!  (For my proctologist I want that keyboard cleaned every five key strokes)

 Seriously I could see this idea being used at any public data entry kiosk. (cash machines, airport check in, etc)

This component pack extends the PSoC Creator 2.1 software with new components providing solutions for temperature calculation, SMBus and PMBus communications, and digital signal filtering.

Temperature Calculators: Three new components compute the temperature based on measurements from a thermocouple, thermistor, or RTD (Resistance Temperature Detector).

SMBus and PMBus Slave: This communication component is built on top of an I2C physical layer and can be configured for System Management (SMBus) or Power Management (PMBus) applications.

Debouncer: This is a hardware-based alternative debouncer to firmware debouncing that eliminates unwanted oscillations on digital input signals, such as those encountered with mechanical buttons and switches.

Glitch Filter:  Another hardware-based alternative to firmware processing, the Glitch Filter eliminates unwanted short pulses (glitches) on digital input signals, which solves the problem of false signal transitions in noisy environments.

The fastest option for installing a component update is by using the Cypress Update Manager which typically takes less than 2 minutes to install with a high-speed Internet connection.
You can find the Update Manager under: All Programs - Cypress - Cypress Update Manager
This program will guide you through the component update process.
Optionally, you can always view the release notes and download the full installer at www.cypress.com/go/PSoCCreator.

PSoC 3, PSoC 5 and PSoC Creator are finalists for EDN magazine's Innovation Awards. Vote at: http://bit.ly/bUkQhb . PSoC Rocks! #psoc

Heading to UNCC tomorrow for PSoC 3 workshops Friday and Saturday. If you are already going to IEEE South East CON come by and check us out.

Cheers

Read more about Starter Designs in the Release Notes of PSoC Creator 2.1

Do you want to use the Programmable Logic Device (PLD) capability of PSoC, and don t know where to start? Or need to create your own custom digital components in PSoC Universal Digital Blocks (UDBs)? Then look no further.

AN82250: PSoC® 3 and PSoC 5 Implementing Programmable Logic Designs An Introduction provides you with an ideal start towards digital mastery with PSoC UDBs. By introducing the PLD architecture, and then walking through an example project, AN82250 teaches you how to create Verilog components in PSoC Creator. For those interested in advanced features of PSoC PLDs and PSoC Creator, these are touched upon in the additional reading material in the appendices.

This application note is actually the second of a three-part series of application notes written to help you learn and exploit PSoC s powerful digital capabilities. This series begins with the introductory AN81623: Digital Design Best Practices, continues with the PLD-centric AN82250, and culminates with the datapath-focused AN81256: Designing PSoC Creator Components With UDB Datapaths.

After reading AN82250, you will be able to implement moderately complex PLD-based components in PSoC Creator. AN82250 also provides a good gateway to building more complex Datapath-based designs dealt with in AN82156. So what are you waiting for? Download AN82250 now!

By Antonio De Lima Fernandes

 http://www.kickstarter.com/projects/18182218/freesoc-and-freesoc-mini

 I was impressed with his video and, in a nut shell; it explained why I am still hoofing around the world, after 12 years, pushing PSoC. I just sponsored him for $100 so I will get a couple of his freesoc.  I figure it is a fairly inexpensive investment.  I will try to get him on PSoC Today. 

Kickstart is a funding scheme that allows people to invest in someone else s idea.  Sort of collective micro funding.

So go look at his proposal and support him if you wish!

PSoC Rocks, Texas A&M Rocks, and so does Jon Moeller

AN82156 - Designing PSoC Creator Components With UDB Datapaths

Have you ever wondered how PSOC Creator manages to pack so much functionality into its components? Chances are the component uses the UDBs in PSoC 3 and PSoC 5 to perform calculations, comparisons, and data management.  The "secret sauce" in the UDBs is the datapath - a configurable 8-bit ALU designed to offload tasks from the CPU. The datapaths, when chained together across UDBs and/or combined with PLD logic, are powerful tools to have at your disposal. Understanding how to use them is an essential part of creating optimized PSoC 3 and PSoC 5 solutions.

AN82156 explains how the datapaths work and teaches you how to develop PSoC Creator components that use the UDB datapaths. It contains step-by-step instructions for creating your first datapath component. The appendices also review the Datapath Configuration Tool and the Verilog code it generates.

If you are planning to create a custom component, you should become familiar with the datapath and the advantages it can offer. AN82156, its example projects, and related on-demand training videos are available today from the Cypress.com website.

AN82156 Landing Page:

• AN82156 - Designing PSoC Creator Components With UDB Datapaths  

On-Demand Videos:

• PSoC Creator 210: Intro to Datapath Components
• PSoC Creator 211: Datapath Computation
• PSoC Creator 212: Datapath FIFOs
• PSoC Creator 213: Multi-Byte Datapath Components
• PSoC Creator 214: Datapath API Generation
   

By Greg Reynolds

 

On the right side of the window, you can see the pinout and list of supported user modules for the selected device.

Note for power users: if you know a portion of the MPN for the device you want to use, you can also just type it in the Find box in the top of the window, and the list will filter live as you type. You can also right-click a device in the catalog to add it to your favorites. These two methods are the quickest ways to select your device.

Here is a video on PSoC Designer Getting Started. This shows how to create a PSoC Designer project to measure an analog signal using a 12 bit ADC and display on LCD. Also a PWM is configured for 1Hz output to blink an LED.  Write to me your feedback to graa@cypress.com

Application note "AN73212 - Debugging with PSoC1" provides all the information required to debug a PSoC1 project.

Happy Debugging!

 I received an e-mail from Amazon with the subject saying Recessed Lightning Cool, I thought and quickly opened it.  It turned out it was for Recessed Lighting and it was only a bunch of stupid lights, but it made me think about what recessed lightning could be.  So I went to Google and after convincing it I really did mean lightning, I figured it must be weather that keeps a school from letting their students outside for break during a thunder storm.  Or maybe it was those plasma balls used as recessed lighting.  That would make a really cool effect for kitchens.  Think not? Well HGTV has many convinced that a kitchen made entirely of concrete is hip and modern.  Trust me this would catch on.

 I looked up plasma balls with led to lighting in a jar which led to making outdoor lighting with mason jars.  So, last night, I got to spend a couple of enlightening (pun intended) mind expanding hours all because I saw a word differently than most.

 Oh. by the way. left and right are not strong concepts for me.  Someone told me a trick to stick out my thumbs and index fingers.  The one that forms the L is your left.  A really stupid idea.  You get a different answer with palms up than with palms down.  Or get the same answer on both if one is up and the other is down.  It also requires that you remember which way an L is supposed to go.  I like my solution. When I was 8, I got a really bad scar on my left elbow.  Until it became automatic, when I needed to know left, I would just grab my elbows.  The one on with the scar was left.  Whe tired, I still occasionally catch myself doing it.  Now in no way do I advocate the intentional scaring of young dyslexics.  Maybe tattoo a finger.  If you are sure they will be engineers then tattoo which fingers on the right hand are for current, voltage, flux, and power.

 Ps  Here is a Dyslexia joke I made up

 Old Mac Donald had dyslexia        O I E E I

I have found that as election time comes around there are friends and coworkers that just have to talk about politics and will not stop.  At least with friends you can delay seeing them till after the election, but with co-workers, you are stuck.

 Well I have a way to just kill the discussion.  When someone is arguing about their candidates soundness or the opponents stupidity just chime in with Did you use those shoes he/she was wearing.   Describe in great detail the shoes and how a simple pump would have been more appropriate.

 Example

Did you see the debate last night?

 Yes I did and did you see HIS shoes?  How does one wear Italian leather this late in the year.  I mean, George Clooney tried it two years ago at the Oscars and it didn t work then. What make him think he could carry it off.  

 Trust me, they will be gone before you get very far.  You don t even have know what you are talking about. For instance, if you say.

 If you are going to wear a Harrison half heal you should at least choose the correct leather type.  I mean Glaviston, lamb leather, are you kidding me? (I have no clue what I just wrote but is sure does sound good.)

So give it a try and if it works for you then buy me a beer.

Tired of clicking on one interconnect row after another, trying to get all your signals to where they need to go? With Designer 5.3, you're done with that! Just shift+click on a block port and a number of glowing, golden lines will show you all the possible destinations. A second click on one of those highlighted locations and you're done! This works on analog routes as well as digital routes, block-to-block or block-to-pin. This will make Designer quicker for your new engineers to learn, and make life easier for the veteran users.

A final note: If you like the control of personally routing your signals, have no fear! We haven't removed any of the existing manual routing features.

The tall building in the center is the new Hyatt. My hotel is forward and to the right (you cannot see it really).

You are looking into Wan Chai on Hong Kong Island in the background.

Moving to a more directly Southern view. Looking at the famous Victoria Peak behind the Central area of Hong Kong Island

I am finding that now, most of the people I work with do not know how to use a slide rule.  10 years ago it was only some.  How could you ever undertand interpolation if you never used a sine table.

Note that the pencil is about 3% eraser, 77% useable pencil, and 20% overhead.  Remember this the next time you are told you should work smarter, not harder. (I have always hated that term.)  Chances are your company's overhead far exceeds your inefficiencies.

Of course, a pencil is only an eraser on a stick, until you sharpen it.

Last Sunday, I had the opportunity to visit the 4th highest commercial building in the world - Sky 100 in Hong Kong.

I took almost 100 pictures. I will upload a few of the best over the next week until you get a 360 degree bird's eye view of Hong Kong.

Until then,

C. U. Around

In PSoC 1, this clock has to be derived from the SysClk or SysClk * 2. Let us take SysClk for this case and assume a SysClk of 24Mhz. To get a frequency of 76.8KHz from 24MHz, the required divider is 312.5. Unfortunately, we cannot have a fraction in the divider and have to round off to 312 or 313. For a divider of 312, the resulting clock is 76.923KHz. This gives rise to a plethora of questions. Is this clock accurate enough? Will I get bit errors because of the deviation in the clock? What is the maximum tolerance allowed in the clock to UART?

Before we get into the answer to the question, let us first derive the maximum error allowed in the UART clock. Picture below shows the UART RX line and the internal 8x clock. The UART data transfer starts with a Start bit, 8 data bits, optional parity bit and ends with a Stop bit.

Ideally, the Receiver samples the RX line at the mid-point of every bit.  If the UART clock has 0% error, then the sampling will happen exactly at mid-point of the Stop bit.  But as the UART clock will have a tolerance, depending on the +ve or ve error on the UART clock, the sampling will happen earlier or later than the mid-point on every bit.  This error keeps accumulating and will result in the maximum error on the Stop bit.  Ideally the maximum error allowed on the Stop bit would be + ½ a bit, ie, 50% of the bit time.  But practically, if we sample earlier or later by 50% of the bit time, we will be sampling at the bit transition.  For systems that have higher bus capacitance and higher rise and fall times, this will create a problem. 

So, allowing for rise and fall times at 20% of the bit time, we have a room of +40% of the bit time in the Stop Bit.  The tolerance allowed on the UART clock is +40% / (No. of Bits).  For an UART with one Start bit, 8 data bits and one Stop bit, the maximum error allowed on the clock would be +4%.  This 4% tolerance has to be split between the devices on the either side of the UART bus.  For example, if a device on one side of the UART bus runs on a crystal at 100ppm, the device on the other side can have a clock tolerance of +3.99%.  Remember, this 4% also is again subject to system performance.  If you are running a very long cable and the UART at a very high baud rate, the rise and fall times may be more than 20% of the bit time and you will have lesser room for error.  AT lesser baud rates and shorter cables, you will have more room for error.

Now let us check the round off error introduced by the divider.  For a 9600 baud, we use a divider of 312 on the SysClk which results in a clock of 76.923KHz against the requirement of 76.8KHz.  The error introduced by this deviation is just 0.1% and is negligible.

The next contributor to the error budget is the tolerance of the clock source which is the IMO.  In most of the PSoCs (CY27x43, CY29x66, CY24x23, etc), the IMO has a tolerance of +2.5% over the full operating temperature.  This is well within the +4% tolerance.  Also, the PSoC boot.asm code writes a factory programmed trim value to the IMO trim register, which further reduces the error of the IMO to <1%.  So, clocking the UART from the IMO will not introduce any problem.

What about the devices which have IMO with a tolerance of >=4% (CY24x94, CY21x34 etc)?  In fact, when you place an UART component in the CY24x94 device, the Design Rule Checker gives a warning that to use an UART, the device should be connected to the USB bus.  When connected to the USB bus, the IMO gets synced to the USB clock and hence will become as accurate as the USB bus clock.  When not connected to USB bus, it runs at +4% tolerance and hence this warning. 
For these devices various options may be considered.

1. What is the device on the other side of the UART? If the device on the other side of PSoC runs on a crystal, then the complete 4% error margin can be used by the PSoC.  Also, though the IMO is specified for an accuracy of >+4%, after the trim in boot.asm, it will be better than +2%.
2. What is the slowest baud rate that you can use in the system?  Lower the baud rate, the rise and fall times will occupy lesser part of the bit time and the tolerance of the UART bus will tend towards 5% and you get more room for error.
3. What is the shortest cable you can use?  Shorter the cable, lesser the bus capacitance.  This will reduce the rise and fall times and the tolerance will tend towards 5%
4. For the CY8C24x94, if you are not using the USB, then you may consider using other devices like CY8C27x43 or CY8C29x66.
5. Use an external 24MHz oscillator and connect this oscillator to P1[4].  In the Global Resources select P1[4] as the SysClk source.

With the above considerations, a robust UART communication can be built in PSoC 1.

Trimming simply means adjusting register values to achieve better accuracy be it for offset of a comparator or the frequency of a clock. For clocks, trimming means calibration with respect to a higher accuracy reference clock.

In the example project associated with the application note (schematic shown above), the IMO is trimmed with a 32 kHz crystal as reference and the ILO is trimmed with the IMO as reference. This enables the IMO to achieve near MHz crystal accuracy (±0.05%) at kHz crystal cost. The ILO performance is also considerably improved with a post-trim accuracy of ±6.5% with respect to the IMO. This means that the respective trim components improve ILO accuracy by a factor of 16, and the IMO accuracy by up to a factor of 140. Moreover, the accuracy can be easily verified on the character LCD (an example is shown below) with a simple API call to check IMO and ILO errors!

I really enjoyed developing these two components. Once you program the example project on the PSoC, zap it with freeze-spray or a heat gun and have fun watching the component correct the IMO and ILO frequencies!

In conclusion, having an accurate MHz clock is important for a wide range of applications, and particularly for high-speed communication. An accurate kHz clock also has many applications, especially in low power modes when MHz clocks are switched off.

The IMO and ILO Trim components really enhance the already-flexible clocking structure in PSoC 3 & PSoC 5, and I hope that they help you out in your specific applications as well. You can download the application note and the components at AN80248's landing page.

By Antonio De Lima Fernandes

To help you learn about and effectively use the UDBs, we're launching a series of new application notes that cover the topic in great detail. The first one, AN81623, PSoC 3/5 Digital Design Best Practices, is intended to introduce designers, especially firmware engineers, to the field of digital design and how it is done with PSoC 3/5.  Forthcoming application notes will give detailed instruction on the use of PLDs, datapaths and other UDB features.

AN81623 gives a brief introduction to digital hardware design theory and then describes the digital subsystem in PSoC 3 and PSoC 5. It also describes best practices for digital design using PSoC Creator, and shows how to use static timing analysis (STA) report files.

So this application note should help you more effectively use the digital components available to you right now - Counter, Timer, PWM, Shift Register, Quadrature Decoder, and more.  And with the Lookup Table (LUT) component you should easily be able to build simple state machines. Then watch for more advanced application notes, coming soon, that will show how to implement your own complex digital designs in the PSoC 3/5 UDBs.

To download this new application note "Digital Design Best Practices" click on this link, AN81623.

By Mark Ainsworth

As a Cypress Semiconductor employee I do not advocate or recommend the illegal downloading of digital music.  It as always worked for me but I can t recommend it.

Professor Renji Mikami

View of Tokyo from Cypress Japan office

I will be presenting a PSoC workshop at TALE 2012 being held at Hong Kong Polytechnic on Monday.

Until Then,

C. U. Around

Good bye Hans, you will be missed!

A private family service will be held on August 17th. A remembrance of Hans life will be held at 2 pm on September 9th, in the Shoup Park Garden House in Los Altos. Friends and colleagues are welcome. In lieu of flowers, the family would prefer donations in Hans memory to the Computer History Museum. To RSVP and for information on donations, please see camenzind.org/hans/.

The second project, 2_WaveDAC8_TwoWaves shows how you can alternate between two waveforms and easily switch right at the end of each wave.  The project schematic is rather simple, and the source code can t get much simpler.

Project source code.

This is the waveform output, notice it is not just a simple sinewave.

The third project "3_WaveDAC8_UART_FSL" shows how to generate a simple FSK output when you combine the WaveDAC8 and UART components.  Note the simplicity of the schematic below.  By changing the two clocks you can generate any two frequencies you want.

The scope screen shot below shows the output of the UART and the WaveDAC8 output.

Again the code can t get much simpler to send out Hello World .

The forth project was probably the most fun.  Who doesn t enjoy dialing their phone with their own custom made PSoC controlled DTMF dialer.   This project used two WaveDAC8 components, a couple of counters, an opamp to buffer the DAC outputs, and a single clock.

This project demonstrates another cool feature of PSoC.  Since the WaveDAC8 component uses standard internal DACs to generate the output,  connecting the two DAC outputs together is not a problem.  When the DAC is in the voltage DAC mode, it is simply a current DAC with an internal resistor.  Now the coolest thing about this project is that it gives you a good chance to use that FFT feature in your digital scope.  I had the DTMF dialer project dial the sequence 159D which causes all of the eight tones to be exercised.  Using the Tek MSO 2024 FFT mode I can see the frequency spectrum of the output, cool eh?

You can find the full application note, example projects, and WaveDAC8 component library on the AN69133 Application Note web page. The application note contains details about the design of the WaveDAC8 and information on sampling theory.

So just remember, although the WaveDAC8 maybe pretty, it has some brains as well.  Since it does all it's work with DMA, it does not require any of the valuable PSoC 3 or PSoC 5 CPU cycles.

By Mark Hastings

Sometimes people get things wrong but the name sticks because no one wants to make the effort to change back.  XOR stands for exclusive OR and its output should be 1 only when a single input is 1.  Its algebraic operator is ^ .  It was originally defined as a two input gate and functioned very well in that form.  The problem is for more than two inputs it is no longer associative ((A ^ B ^ C) (A ^ B) ^ C.  So the definition was changed to define the output as 1 when an odd number of its inputs are 1.  It really should be called an ODD gate but then again a Koala shouldn t be called a bear or a tomato a vegetable. A peanut is neither a pea nor a nut and we won t even go into sweetbreads.  Just get over it.

Identities           0 ^0 = 0

                        1 ^ 1 = 0

                        1 ^ 0 = 1

                        A^ 1 = ~ A

                        A ^ 0 = A

                        A ^ A= 0

                        A ^ ~A= 1

                        (A ^ B ^ C) = (A ^ B) ^| C (associative)

                        A ^B= B ^ A (commutative)

 I needed about 1/8 of a tube of air duct mastic and I ll be dammed if I will pay $5 for a tube of it.  I am installing the dust collection system for my new wood shop and since I am in Arizona I decided to use metal 6 pipe.  With the humidity so darn low, dust explosions are possible so plastic pipe is out.  I first decided to invent empty caulking tubes but after checking on the web I find they already have them, but they cost more than a cheap tube of latex caulk.  So I took a very cheap tube of water cleanable caulk and emptied it.  I next used my compressor to blow back the plunger.  With 100 psi, it popped like a champagne cork.  I washed it out, filled it with left over mastic, and finished the job.  Easy Peasy!  I even cleaned out the tube so I have it for the next time.

My shop is almost finished so when I have my Open Shop party, I will take food grade caulk tubes and empty out so that they can be filled with topping for canapés.  I ll have the servers. (This will be a catered event!) dispensing different toppings from caulk guns There will be guacamole, salsa cream cheese, red mango pickle cream cheese,  American cheese spread, spicy bean dip, and maybe straight bacon fat for the hard core.  You just pick up a chip or cracker and a server will come over and cheerfully dispense the amount of your favorite toping you want.  No need to double dip. After three drinks it is acceptable to have the server shoot the topping straight into your mouth.

It will be a great party.  Hope you can come.  I have registered at Home Depot and Woodcraft.

Master& Slave have been around a long time and of course these terms are insensitive enough as to be banned from use in some parts of the US.  I like Host & Device. I particularity like Corporate Oppressor & Employee as it is quite descriptive.

 I have seen Parent & Child used but these days, to be consistent, you should also have Step Parent, Step Child, Step Sibling that gets better response from Parent than you, Friend that lives with Parent that you have to acknowledge as Parent but really isn t and won t be around much longer anyway, Ex Step Parent that you can acknowledge if you wish but you don t have to, etc.  The more I think about it the more I am liking this description.

 The other thing is direction.  For USB every thing is Host centric.  So if you are a device, then a read is actually a write to the host.  It s like the airport.  When I go to the airport to go on a trip I instinctively want to drive the Arrivals section because I have just arrived.  Why can t they call it To Host and From Host or To Device and From Device.  (TH FH TD FD for short.)

 So if have some descriptive terms for both side of a USB system, please send them in.  I will give 050 kit for the best entry.  Please keep it good taste or at least not in bad taste.