Graphics LCD problem with Cyclone III FPGA Development Kit

Your problem is that you replaced my glcd_write() parts of the code by directly writing to the port pins. This is the crucial initializing step and should be done as i did in my code using the following glcd_write() function:

void glcd_writeByte(int DI, int data)

{

if (DI == 1)

{

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_D_CN_BASE, 1); //write a command;

}

else

{

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_D_CN_BASE, 0); //write data;

}

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_DATA_BASE, data); //put DATA on the data lines;

usleep(2); //wait 2 us

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_EN_BASE, 0); //pull the ENABLE pin low to enable writing to the LCD

usleep(2); //wait 2 us

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_WEN_BASE, 0); //pull the Write Enable pin low to enable writing to the LCD

usleep(2); //wait 2 us

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_WEN_BASE, 1); //pull the ENABLE pin high to disable writing to the LCD

IOWR_ALTERA_AVALON_PIO_DATA(GLCD_EN_BASE, 1); //pull the Write Enable pin high to disable writing to the LCD

}

This should then work. Just another thing: the data pins should actually be bi-directional pins to allow reading from the GLCD as well - just thought i will mention it.

I would like to know if this works with your display and what the display looks like after you have initiallized it.