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CapSense® Plus

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Block Diagram - CapSense® Plus
PSoC Peripheral of the Month initiative provides design golden nuggets for our PSoC fans! Every month, we hand pick a design peripheral implemented using the programmable digital and analog inside PSoC that can solve the unique challenges in your embedded system design in the most cost efficient manner. For each peripheral, we wrap it around with technical collateral, trainings, design hardware and software components. Everything you need to enjoy the integration, acceleration, and innovation benefits of PSoC designs. Enjoy!
PSoC 3® and PSoC 5® offer the industry's first programmable solution with built-in capacitive-sensing capability that can also perform general system control functions. To accomplish this task, our solution combines two premier Cypress product offerings, the PSoC programmable system-on-chip and the industry-leading CapSense capacitive touch control technology


Design Considerations
When designing capacitive touch sense technology into your application, it is crucial to keep in mind that the CapSense device exists within a larger framework. Careful attention to every level of detail from PCB layout to user interface to end-use operating environment will lead to robust and reliable system performance. For more in-depth information, refer Getting Started with CapSense.

What is SmartSense™?

Cypress's revolutionary, patent-pending SmartSense™ auto-tuning algorithm, which eliminates the requirement for system tuning. SmartSense enables automatic tuning of more than 10 parameters to achieve optimal touch sensing performance.

SmartSense™ Advantages

 1.  Auto-tuning: Competitor solutions require FW changes / use of interface boards for configuration changes, SmartSense takes care of the tuning without user intervention.
 2.  Time Saver: Saves a lot of time by avoiding manual tuning during development.
 3.  Process change: No re-tuning required when there is PCB process change / PCB vendor change (for cost reasons) / sensor characteristics change.
 4.  Overlay change: No re-tuning required when overlay material or thickness change.
 5.  Environment change: No re-tuning needed when the noise conditions change making the CapSense module

What is CapSense Tuner?

The graphical CapSense software module in Cypress's PSoC Creator™ IDE makes it easy for designers to define combinations of buttons, sliders, touch pads and proximity-sensing capacitive sensors, and offers real-time feedback of parameters such as signal-to-noise ratio (SNR), finger threshold, noise threshold, and more.

The module features include:

 1.  Supports user defined combinations of button, slider, touch pad, and proximity capacitive sensors
 2.  Provides automatic SmartSense tuning or manual tuning
 3.  High immunity to AC power line noise, EMC noise, and power supply voltage changes
 4.  Optional two scan channels (parallel synchronized) increases sensor scan rate.
 5.  Shield electrode support for reliable operation in the presence of water film or droplets
 6.  Guided sensor and terminal assignments using the CapSense customizer

 1.  Overlay Selection
    •  To increase the CapSense signal strength, choose an overlay material with a higher dielectric constant, decrease the overlay thickness, and increase the button diameter. Conductive material cannot be used as an overlay because it interferes with the electric field pattern. For this reason, do not use paints containing metal particles in the overlay.

 2.  ESD Protection
    •  Robust ESD tolerance is a natural by-product of thoughtful system design. By considering how contact discharge will occur in your end product, particularly in your user interface, it is possible to withstand an 18-kV discharge event without incurring any damage to the CapSense controller.

 3.  Electromagnetic Compatibility Considerations
    •  Radiated Interface: Radiated electrical energy can influence system measurements and potentially influence the operation of the processor core.
•  Radiated Emissions:Selecting a low frequency for the switched capacitor clock will help to reduce radiated emissions from the CapSense sensor.
•  Conducted Immunity and Emissions: Noise entering a system through interconnections with other systems is referred to as conducted noise. These interconnections include power and communication lines. Because CapSense controllers are low-power devices, conducted emissions must be avoided.

 4.  Software Filtering
    •  Software filters are one of the techniques for dealing with high levels of system noise.

 5.  Power Consumption
    •  From the system design perspective, methods to reduce power includes: set GPIO drive mode for low power, turn off the high-power blocks, optimize CPU speed, etc.
•  In typical applications, the CapSense controller does not need to always be in the active state. The device can be put into the sleep state to stop the CPU and the major blocks of the device.
•  In any application, if both power consumption and response time are important parameters to be considered, an optimized method can be used that incorporates both continuous-scan and sleep-scan modes.

 6.  Pin Assignment
    •  An effective method to reduce interaction between CapSense sensor traces and communication and non-CapSense traces is to isolate each by port assignment.

Development Kits/Boards
Cypress is aiming at giving engineers access to the complete PSoC ecosystem to create powerful, customized designs, and ease customers� ability to re-use CapSense designs within the PSoC environment. We are offering the CY8CKIT-031 PSoC CapSense Expansion Board Kit to speed designs with the new solution. The CY8CKIT-031 includes both button and slider modules, three separate overlays for prototyping, and a resource CD with example projects and application notes. The new kit�s adapter board allows engineers to plug in existing CapSense modules into the CY8CKIT-001 PSoC Development Kit, the CY8CKIT-030 PSoC 3 Development Kit, or the CY8CKIT-050 PSoC 3 Development Kit.

The CapSense modules kits include the CY3280-BSM Simple Button Module Kit, the CY3280-SRM Radial Slider Module Kit, the CY3280-SLM Linear Slider Module Kit, and the CY3280-BMM Matrix Button Module Kit.

CY3280-BMM Matrix Button Module Kit

CY3280-BSM Simple Button Module Kit
The CY3280-BSM Simple Button Module Kit is designed to work with any CY3280 Universal CapSense Controller Board, such as the latest CY3280-20x66 DVK.

CY3280-SLM Linear Slider Module Kit

CY3280-SRM Radial Slider Module Kit

CY8CKIT-001 PSoC® Development Kit

CY8CKIT-030 PSoC® 3 Development Kit
The CY8CKIT-030 PSoC® 3 Development Kit enables you to evaluate, develop and prototype high precision analog, low-power and low-voltage applications powered by Cypress’s CY8C38 high precision analog device family.

CY8CKIT-031 - PSoC® CapSense® Expansion Board Kit
The CY8CKIT-031 PSoC® CapSense® Expansion Board Kit enables you to develop CapSense solutions with PSoC 3 and PSoC 5 devices.

CY8CKIT-050 PSoC® 5LP Development Kit


PSoC® 3 and PSoC® 5 are true programmable embedded system-on-chips which integrate configurable analog and digital peripherals, memory and a microcontroller all on a single chip. These breakthrough architectures boost performance through:

• Integrated high-precision 20-bit resolution analog
• Ultra low power with industry’s widest voltage range
• Programmable PLD-based logic
• Single-Cycle 8051 core up to 67 MHz (PSoC 3) or 32-bit ARM® Cortex™-M3 CPU up to 67 MHz (PSoC 5)

Training On-Demand

PSoC 3 and PSoC 5 106: Introduction to CapSense Touch Sensing
This module introduces the CapSense touch sensing peripheral of PSoC 3 and PSoC 5 devices that can be implemented using PSoC Creator.



Software and Drivers

PSoC Creator
PSoC Creator is a state-of-the-art software development IDE combined with a revolutionary graphical design editor to form a uniquely powerful hardware/software co-design environment.

PSoC Designer
PSoC Designer is the revolutionary Integrated Design Environment (IDE) that you can use to customize PSoC to meet your specific application requirements. PSoC Designer software accelerates system bring-up and time-to-market.

Spec No: None; Sunset Owner: HMI; Secondary Owner: GHR; Sunset Date: 06/15/20