CHAR LCD in PSoC 5 is not working anymore

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Anonymous
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I made a program for psoc 5 where i used the char lcd, and was working fine, then i made some modifications and everything but the LCD worked. i made a new program that print a simple hello message and it didn´t work, i try changing the port and the lcd and nothing happened. i exported the hello program to psoc  and it worked fine. 

   

anybody have an idea of whats going on.

   

 

   

thanks.

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1 Solution
Bob_Marlowe
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Some pins of the PSoC5 Prototyping Kit are buffered with large capacitors. This will hinder LCD to work on those ports.

   

Look at schematic excerpt.

   

 

   

Bob

   

View solution in original post

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rola_264706
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        Please send your program so we can check it.   
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Anonymous
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of corse, but the program couldn't be simplier :

   

#include <project.h>
int main()
{
//    CyGlobalIntEnable; /* Enable global interrupts. */
    LCD_Start();
    LCD_Init();
    LCD_Position(0,0);
    LCD_PrintString("Hola");
    for(;;){

   

    }
}

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rola_264706
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I want to try it on my setup to see if it is wired correctly and your code is correct. You need both LCD_Start() and LCD_Init() is done in the LCD_Start() so it is not needed. You only need LCD_Start().

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Anonymous
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i try with and without the init() i didn´t work the conections are correct the same code works in a psoc 4

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rola_264706
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Are you using a PSOC 5 LP kit?

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rola_264706
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Here is a program that puts some data on the LCD screen. Hope it helps.

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Anonymous
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im using thhe prototping kit for psoc5lp

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rola_264706
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Did my program work? Please send a pin out of the connections to the LCD module so I can check it.

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rola_264706
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Here is the Pin out for the LCD device.

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Anonymous
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thanks for the program but it didn´t work, im buying a new kit to see if it is damaged

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Anonymous
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test it in a new module, didn't work either. it as the same connections

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rola_264706
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Let us know if the new board fixes the issue. I have found these board to be very robust and I have never had an issue with them. I would check your wiring on the LCD module and make sure it is correct. It is easy to wire it incorrectly or miss a connection.  One other thing  some of the  components of the PSOC 4 and the PSOC 5 are different and could cause your problem. It would have been great to check your program but you never sent it.

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Anonymous
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This is the original program, it was working on a pcb i made.  but doesn't work an more, at least the LCD part, the rest is still working.

   

The problem appear to be the LCD is not being initialized.

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EvPa_264126
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It works program

   

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EvPa_264126
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A simple way to check

   

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Anonymous
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ill try that tonight thanks

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rola_264706
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Your program works fine on my LCD I get a lot of 0's running through the screen as I don't have the rest of your hardware. It fails to work if the R/W pin is connected to the P2.1 it should be grounded for it to work correctly. Also my LCD is not the same as yours but shouldn't make any difference.

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rola_264706
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I have work on it some more and I am getting a correct readouts.

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rola_264706
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I am sending you this information as a help P2.1=D4 P2.2=D5 P2.3=D6 P2.4 =D7 P2.5=E P2.6=RS PS.7=R/w Your backlight I moved to P0.0 but you can move it to any free pin.  I am also sending your program back to you with these changes.

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Anonymous
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I check a simple hello program and i found out it works on ports 1 and 2 of the prototyping kit, but not on ports 3 and 0. 

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Bob_Marlowe
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Some pins of the PSoC5 Prototyping Kit are buffered with large capacitors. This will hinder LCD to work on those ports.

   

Look at schematic excerpt.

   

 

   

Bob

   

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Anonymous
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i made another test on port 2 and if i use a cpu clock higer than 24MHz some times i lost some characters (it still displays part of the message)

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Bob_Marlowe
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There are delays in the code to access the LCD. Probably your device needs longer delays. You may change the code, but it will get overwritten on a new build, so make a copy, renale it and then apply changes.

   

 

   

Bob

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Anonymous
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this is the program that some times displays part of the message. if a change cpu clock to 24MHz it displays correctly . On port 1 fails less, but still some times characters are missing

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rola_264706
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What clock speed are you using?

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rola_264706
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I don't know what your application is going to do or if you plan to run it on a battery source but the slower the clock the less power it will use.

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rola_264706
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Also we have no ideal what LCD component you are using an what the SPEC's are so we don't know if it has a max speed for the display signals.

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Anonymous
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Power is not an issue in my application, but speed. im using te maximum permitted frequency on the pll: 76.8MHz. The LCD im using is JHD-162A. I´ve use it before without problems in PSoC 1 and 4.

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rola_264706
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The program is running at 24Mhz which produces 76.8Mhz Pll. See attach Clock sheet. Also Port Two is the Port that should be used by the LCD component. Your Program is stable on my machine at 24Mhz clock. The PSOC 4 PLL runs at 45mhz a lot slower than the PSOC 5lp.

   

   

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