Problems with Olimex TMS470 dev. board LCD display

Development Boards MicroMod
1

I am using Keil uVision to program my microcontrollers. Using the Keil uLink.

I found the example for LCD code on the olimex site but it isn’t made for Keil so I did rewrite it so I can use it with Keil.

I can get a blinking cursor on it… but I can’t get any characters on it. When I write A… he moves down a line and put in a space… if I write a the cursor just disappears. Here is my code for writing characters can someone help me out?

void LCDSendChar(unsigned long a)
{
  delay(4000);                          //delay for LCD char ~2ms
  data = 0x0;

  data = 0xffffff0f | a;                //get high 4 bits
  pGIO->GIOA.GIODOUT &= 0xffffff0f;     //clear D4-D7
  //data = data << 16;

  pGIO->GIOA.GIODOUT = (pGIO->GIOA.GIODOUT | 0x000000f0) & data;    //set D4-D7
  pGIO->GIOB.GIODOUT = 0x02; 			//set RS port to 1 -> display set to char mode
  E_Pulse();                            //pulse to set d4-d7 bits

  // clear data and shift data to get low 4 bytes :-)
  data = 0x0;
  a = a<<4;

  data = 0xffffff0f | a;                	//get high 4 bits
  pGIO->GIOA.GIODOUT &= 0xffffff0f;         //clear D4-D7
  //data = data << 16;

  pGIO->GIOA.GIODOUT = (pGIO->GIOA.GIODOUT | 0x000000f0) & data;    //set D4-D7
  pGIO->GIOB.GIODOUT = 0x02;                //set RS port to 1 -> display set to char mode
  E_Pulse();                              	//pulse to set d4-d7 bits

}

I did use E_Pulse also to init the LCD so I guess that one is allright. Also LCDSendCommand seems to working because putting in spaces and a blinking cursor works.

2

http://www.myke.com/lcd.htm

I found this site… he is saying “write 0x02 to the LCD to Enable Four Bit Mode” but this isn’t right, is it?

Well the whole command mode is working… but when I want to write a character it isn’t. I put RS to 1 … and when I measure it on the LCD I find 3,3v so that’s ok. But still he does everything in command mode. It seems like he doesn’t see a 1 on his RS input. how is this possible?

Fixed: E_Pulse() did put RS low

3

I hacked up some of the TI code to make it work a while ago. I think it may be posted in one of the Yahoo Groups TI TMS470 groups file section of example code.

Sandy