Cant get LCD screen to work with Psoc 3 firsttouch starter kit.

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Anonymous
Not applicable

 Hej 

   

 I cant get my LCD screen to work at all. I have followed the example in the pdf file.

   

http://www.cypress.com/?docID=33243

   

set it up by trying to use port 6 or port 0 but it will still not work. the program code is copied directly from the example and doesnt give any errors.

   

I am using a 1k potmeter for the display. 

   

have moved the jumper so i get a 5V output from VDD.

   

when i build nothing happens on the screen. when build is finished i unplug the psoc 3 from the pc and plug it in again, nothing happens.

   

what could be the problem?

   

hope you guys can help

   

regards Jason

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1 Solution
Anonymous
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        Oh! I find it more, Please check actual voltage at LCD-Vdd again, Is it enough? If it's less than 4.5v, LCDs doesn't work, No display. When suplly from Mini-prog or USB-bus, It was happen several times. Thank you..   

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32 Replies
Bob_Marlowe
Level 10
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What kind of LCD module are you using on the firsttouch kit and which usermodule are you using?

   

If you do not mind, post your complete project here, so that we all can have a look at.

   

To do so, use "File -> Create Workspace Bundle (minimal)" and upload the resulting .zip file here using ms internet explorer (NOT CHROME!!)

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ETRO_SSN583
Level 9
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The LCD must be 44780 controller compatible for starters. Also the project

   

is available on opening screen under Examples and Kits, to make sure you

   

have a  good starter project. LCD contrast adjustment also must be done

   

with a pot.

   

 

   

Best to post your project, and the schematic you have implemented.

   

 

   

Regards, Dana.

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Anonymous
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 I have tried two lcd screens.

   

   

MDL-16265
http://www.alldatasheet.com/datasheet-pdf/pdf/165398/VARITRONIX/MDL-16265.html

   

DEM20485

   

http://www.gaw.ru/pdf/lcd/lcm/Display/char/DEM20485SYH-LY.PDF

   

Pin connection.

   

P6_0 - DB4 - pin 11 on lcd
P6_1 - DB5 - pin 12 on lcd
P6_2 - DB6 - pin 13 on lcd
P6_3 - DB7 - pin 14 on lcd
P6_4 - E      - pin 6 on lcd
P6_5 - RS   - pin 4on lcd
P6_6 - R/!W - pin 5 on lcd

   

i have also tried port 0.

   

P0_0 - DB4
P0_1 - DB5
P0_2 - DB6
P0_3 - DB7
P0_4 - E
P0_5 - RS
P0_6 - R/!W

 

   

I have attached the program as instructed. if you need any further information let me know.

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ETRO_SSN583
Level 9
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Display is compatible, you are connecting a pot to Vdd, other side to Vss, and wiper to Vo to adjust

   

contrast ? Also your project settings are 5V, as display is 5V.

   

 

   

You have the right pin numbers in post, you sure you got pin 1 orientation on display left side of

   

pins when display is oriented with pin connection holes at top ?

   

 

   

You issued

   

 

   

LCD_Char_Init( );

   

LCD_Char_Start( );

   

 

   

Do not use chrome to post a project, your project did not get posted.

   

 

   

Regards, Dana.

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Bob_Marlowe
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You forgot the project...

   

 

   

Bob

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Anonymous
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I have uploaded it now with explore

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ETRO_SSN583
Level 9
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First the LCD settings must be -

   

 

   

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Anonymous
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Have set it to none.. doesnt change anything.

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Anonymous
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Dana:

   

I am using a 1k Pot that is connected to VDD, pin 3 on lcd(vo) and vss.

   

I have moved the jumper so i get 5V at VDD. the jumper is in position 2 and 3.

   

the display is marked 16 in one end. so the other ends first pin is connected to gnd.

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ETRO_SSN583
Level 9
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You had a couple of double underscores in f() api names used, this works -

   

 

   

#include <device.h>
#include "LCD.h"

uint8 i = 0;

void main() {

    LCD_Init( );
    LCD_Start( );

    LCD_Position(0, 0);                             //Positions the cursor
    LCD_PrintString("Hello World");                 /*Prints the null terminated string Hello World at (0,0)*/

    for(;;) {

        CyDelay(1000);                                 //1 sec Delay
        LCD_Position(1, 0);
        LCD_PrintNumber(i);                         //Prints the value of i
        i++;
    }
}

   

 

   

Regards, Dana.

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Anonymous
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 try look at the last example i uploaded dana.

   

i have taken the example from cypress directly.

   

regards Jason

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Anonymous
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 when i compile the code you gave me dana it gives me a warning.

   

WARNING: C:\PSOC3\LCD_DISPLAY\LCD_DISPLAY\LCD_DISPLAY.CYDSN\MAIN.C:21: 'LCD_Init': missing function-prototype

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Anonymous
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when building it get this warning.

   

   

*** WARNING L25: DATA TYPES DIFFERENT

   
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ETRO_SSN583
Level 9
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I am using "PSOC Creator Component Pack 5", maybe thats

   

the issue. Compiles and runs fine on this end.

   

 

   

Try it w/o Init() but I think thats needed.

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
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Make sure you don't have a double '__' (underscore) in          LCD_Init( );

   

 

   

Regards, Dana.

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Anonymous
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 I am using creator 1.0. higher versions are not compatible with the psoc 3 version i have.

   

there is no dobble line (__)

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ETRO_SSN583
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I think the Init( ) got added later, so try it w/o.

   

 

   

Regards, Dana.

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Anonymous
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 the warnings are removed but i still dont have any picture ?

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ETRO_SSN583
Level 9
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What is the contrast pin tied to ? Should be a pot to allow 0 - Vdd.

   

Normally a display with bad contrast will be dark block characters,

   

you see any of this ? Kit jumpers and project settings consistent

   

with 5 V operation ?

   

 

   

Laslty if you look at LCD data sheet, revision section, quite a lot of changes,

   

some timing related.

   

 

   

There is an exchange program for that kit to the full 030 board, maybe that

   

would be good to execute on, and get you into current Creator Version. versions

   

fix bugs, some w/o workarounds. www.cypress.com/

   

 

   

Regards, Dana.

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Anonymous
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        When the board doesn't working ever, I am used to do that, Every each wiring wasn't shorted to ground? Each wiring wasn't bridge to near terminal? Each wiring was connect correctly? This article has a bundle project, that using LCD, by PSoC3 and port is 6. This might be help you? http://www.cypress.com/?app=forum&id=2232&rID=75317 Happy LCD!   
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Anonymous
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LCD_Init( ); is not needed as it is called inside LCD_Start().

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ETRO_SSN583
Level 9
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Looks like datasheet should be cleared up on both start() and init() functions, eg.

   

description.

   

 

   

Regards, Dana.

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Anonymous
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 exactly

   

Lcd_Start()   should be enough. i have dobble check the wires several times. I am completly lost at this point.

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Anonymous
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if all wires seem to be properly connected (you have done continuity checks with a meter) and you see proper voltages on the pins. The first thing I would do is check if the LCD is atleast working (powered).

   

To do this just play with the contrast pot, if its working you should start seeing the pixels get darker as you get to one of the extremes of the pot. on the other side it should get completelly white and see nothing.  If you see no change then check lcd power again.

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Anonymous
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danaaknight

   

You are probably right. I haven't thought about it. The first time I ever used a Char_LCD module (without having looked at the example project) I've also tried to use Init(), but since it is not even listed in Char_LCD.h I quickly looked at the source and realised it was not needed.

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Anonymous
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        Once ever this was happened to me, As long as see the wire it was soldered properly but wire was not connected electrically. Some these matter is often happen. I know you did double check. And LCD unit is easily broke In the electrostatic breakdown. If you touch it by bare hand, it malfunction very often, because it made by COB chips. Do you have another LCD unit for replace. Finally, You might need check by Logical analyzer. Thank you..   
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Anonymous
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        I find it your design have two LCDs, What a gorgeous! I was quite missed this point. If two module interfering each other, by registers or global object.. So on, I have add 2nd LCD to my test-design port-0. (of course 2nd LCD was only implement but not physically) It is working well. Thank you..   
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Anonymous
Not applicable
        Oh! I find it more, Please check actual voltage at LCD-Vdd again, Is it enough? If it's less than 4.5v, LCDs doesn't work, No display. When suplly from Mini-prog or USB-bus, It was happen several times. Thank you..   
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Anonymous
Not applicable

Have you managed to make it work? if so, what was the cause of the problem?

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Anonymous
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 Hello everyone

   

I finally got it to work.

   

I had two errors. I had a loong testing face so i had tried to put the jumper to a 3.3V position and forgot to put it back to a 5V position.

   

second error was in my potmeter. I switched it to a new one and VOILA it worked. I just had to turn it all the way to the right before i got a display.

   

So thanks for the help everyone. I can finally continue with my project.

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Bob_Marlowe
Level 10
Level 10
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That was one week of searching for an error... Too bad, I can feel with you!

   

 

   

Bob

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Anonymous
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Small mitakes, has hapened to all of us. The best solution is to take a break or ask someone with fresh eyes to check for you.

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