LinuxQuestions.org - LCD UDB Edition 1 / DE-LD011

Hello,

I bought a "LCD Display USB (Edition 1)". I can use this very simple device over USB.

Linux says me, that the device is a "cp210x" usb2serial-device. That's ok. "cp210x" creates me the device "/dev/ttyUSB0". This device, i think, should be used to program the LCD.

I searched and i searched, but i didn't find a needable software to program the device. May the communication is no standart? But, no problem, there are only a few commands. They're descripted in a pdf:
http://www.sure-electronics.net/down..._Ver1.0_EN.pdf

For example:
0xFE 0x46 Should turn the backlight off.
0xFE 0x42 0x00 Should turn the backlight on.
0xFE 0x98 0x[01-FE] Should define the the brightness of the LCD.

There are a few other commands. But the only one that works for me is the command to turn the backlight off. Why?

All the other commands do nothing... May be i make something wrong. Or there's a software for this board?

I use this code to configure the LCD:

Code:

//

//DislayTest.cpp

//

#include <termios.h>

#include <stdio.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/signal.h>

#include <sys/types.h>



#define BAUDRATE B9600

#define device "/dev/ttyUSB0"

unsigned char ClearScreen[] = {254,88};

unsigned char backoff[] = { 0xFE, 0x46

//'a', 'b', 'c', 'd',

//'e', 'f', 'g', 'h',

//'i', 'j', 'k', 'l'

 };

unsigned char WelcomeMessage[] = {'H','e','l','l','o',' ','W','o','r','l','d','!'};



int main(int argc, char *argv[])

{

      struct termios term;

      //Open the serial port

      int lcd = open(device, O_RDWR | O_NOCTTY | O_NONBLOCK);



      //handle errors

      if (lcd < 0)

      {

              printf("Error opening serial port %s\n",device);

              return -1;

      }



      //Setup the serial port 8 data bits, no parity ,1 stopbit, no flow control

      term.c_cflag = BAUDRATE | CS8 | CSTOPB | CLOCAL | CREAD;

      term.c_iflag = 0;

      term.c_oflag = 0;

      term.c_lflag = 0;

      tcflush(lcd, TCIFLUSH);

      tcsetattr(lcd,TCSANOW,&term);



      //Write Welcome Message to the display

      //write(lcd,ClearScreen,sizeof(ClearScreen));

      //write(lcd,WelcomeMessage,sizeof(WelcomeMessage));

        write(lcd, backoff, sizeof(backoff));



      //Close the display

      close(lcd);

      return 0;

}

Thanks,

best regards
toredo

-edit-

I listend on my windows machine with the tool portmon the serial port with the device. Then i used LCD Smartie to work with the device. The communication looks ok.

After this i tried to write a c#-tool for the device:

Code:

SerialPort sp = new SerialPort("COM24");

sp.BaudRate = 9600;

sp.StopBits = StopBits.One;

sp.DataBits = 8;

sp.Open();

foreach (int n in Enumerable.Range(1, 254))

{

    sp.Write(new byte[] { 0xFE, 0x98, (byte)n }, 0, 3);

    Thread.Sleep(10);

}

sp.Close();

It works perfeclty! It's very simple and stupid. It makes the background light in litle steps haler. all other commands work too.

But, i tried this to write in Perl or C. but it never worked? As base i used to C-Code upside. For Perl i used Device::SerialPort.

May my parameters are bad?

Has anyone an idea?

best regards
toredo