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PSOC 5, Cannot succeed a simple "HELLO WORLD" with Character LCD! | Cypress Semiconductor

PSOC 5, Cannot succeed a simple "HELLO WORLD" with Character LCD!

Summary: 9 Replies, Latest post by aumontcabot.olivier_1630851 on 28 Nov 2016 10:03 AM PST
Verified Answers: 2
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Hello everyone, 

 

I am currently using a PSoC 5LP CY8C5888LT*-LP097 (dev kit) and I am trying to do a simple "Hello World" test with the DF-ROBOT lcd shield V2.0 and keep failing.

The symptoms are :

- The LCD seems to receive commands from the mcu but instead of having the expected behavior, it randomly move the cursor, write distorted characters and sometimes does not even display the two lines. My guess is that the commands used in the library are not being read correctly in the LCD even if it is supposed to use HD44780.

 

There is nothing special in the psoc creator project as I simply added the LCD_CHAR component and set the pins on the correct LCD port.

 

*The LCD is connected with parallel communication using the P0[7:1] port: DB4 0[1] to DB7 0[4], E 0[5] and RS 0[6].

* The  R/W pin on the lcd is connected to ground so it is always in "write" mode.

* The R/!W on the Mcu isn't connected.

* The display is powered and back light is on.

* I have tried many projects found on this forum without success.

 

 

Am I missing something ?

 

user_242978793's picture
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1029 posts

Please post your code so we can check it. I have one of the DF lcd shields it worked with my PSOC 4 pioneer kit no issues. However due to the fact that it is an Arduino shield the pin out interface can be an issue. I am sorry you are having issues with some of the examples. Don't forget that most of the example code sent to the forum have issue's that is why it was sent. The examples in Psoc Creator should work providing you hook it up correctly.

user_242978793's picture
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1029 posts

R/W pin should not be grounded it should go to P0(7). See is that makes a difference.

user_242978793's picture
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1029 posts

I always  like to use a component that cypress developed to allow you  to use multi port pins and works well I am sending you a program with this component. I haven't tried it with the PSoc 5lp device but it should work.  This component doesn't require that you use the R/W pin and it can be grounded.  I am sending you a PSoc 5lp program. In this program is also the wiring for the DF module. 

Hello Bob and thanks for the great work.

Effectively, the project you sent works perfectly as is.  The thing is I made a PCB for a triphase inverter and connected pins 0[0] to 0[7] to a header for protyping. Now, I tested your file on a breadboard in case my PCB was problematic (we never know!). It work with the pins you have selected but when I change the pins for pins 0[0] to 0[5] the LCD doenst work. Maybe one of those pins should not be used for the LCD?

 

You can see the header in question in the lower left corner:

edit: please dont look at the flux mess all over the board =)

Turns out that pins 0[2] to 0[4] can't be used directly with LCD. Any ways to make them work ?

user_242978793's picture
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1029 posts

Can you send me a schematic of the DF lcd shields you are using. Also if you are using the lower bank of the lcd those are not needed to make it work.

user_342122993's picture
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578 posts

On KIT-059 there are capacitors attached to pins P0_2 and P0_4. See layout diagram:
http://www.cypress.com/forum/psoc-community-components/annotation-librar...

Use other pins or remove caps

user_242978793's picture
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1029 posts

I forgot to mention that you have to review the schematic of the Psoc kit you are using for caps led's and other components that may cause issues on your signal lines. If you are using your own design for the Psoc part this is not an issue.

Hello, thank you for your answers. I am using the dev kit and the capacitors are the reason the digital pins are not communicating with the LCD.

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