I'm using an AVR ATmega644 to control a SparkFun LCD-00710. However, the code I downloaded from the internet (AVR to 128x64 Graphics LCD Interface) seems to be not working. That is, when I program the AVR and hook it up to the LCD, nothing happens.
I've narrowed down the problem. Using a logic analyzer, I realized that my ENABLE signal is not being pulsed (I believe it has to go from 1 to 0 for the instruction to be executed). In the code that I downloaded, it has these two lines:
#define LCD_E_HIGH (PORTD |= (1<<5))
#define LCD_E_LOW (PORTD &= ~(1<<5))
Then, to set ENABLE high or low they simple just use
LCD_E_HIGH; or
LCD_E_LOW;
Does anyone see a problem with these? For some reason they are not triggering the enable. Or can someone explain what the first two instructions do?
Thanks again!
I've narrowed down the problem. Using a logic analyzer, I realized that my ENABLE signal is not being pulsed (I believe it has to go from 1 to 0 for the instruction to be executed). In the code that I downloaded, it has these two lines:
#define LCD_E_HIGH (PORTD |= (1<<5))
#define LCD_E_LOW (PORTD &= ~(1<<5))
Then, to set ENABLE high or low they simple just use
LCD_E_HIGH; or
LCD_E_LOW;
Does anyone see a problem with these? For some reason they are not triggering the enable. Or can someone explain what the first two instructions do?
Thanks again!