nsubra2001
Newbie level 4
s6a0069
I am connecting a Motorola MC68HC908QY2 microcontroller to a Lumex LCM-S01602DTR 16X2 LCD display that uses a Samsung S6a0069 LCD driver. I am connecting the control pins to Port A (R/W, RS and E pins). I am using the unbuffered signal generator to generate the signal for E. I want to use the 4bit mode using 4 pins on Port B. These are the problems I am encountering:
1. When I initialize for 4 bit, at the end, looks like there is a data bit F(hex) remaining. So when I send the data, I have to send a dummy low nibble to complete the 8 bit and then use the clear display and return home commands to get rid of this spurious data. For initialize, I am using the sequence published by Samsung which is the same as the one published by Hitachi for HD44780. What is wrong with the initialization procedure for 4bit communication?
2. When I set the address as 'C0' for memory location 40(hex), the data sent after setting this address is not displayed on the second line. The data is overwritten on the first line itself. How should I correct this problem? This is not happening when I use 8bit communication but I need the 4 output pins for other controls.
Please help
Thanks,
Narayanan
I am connecting a Motorola MC68HC908QY2 microcontroller to a Lumex LCM-S01602DTR 16X2 LCD display that uses a Samsung S6a0069 LCD driver. I am connecting the control pins to Port A (R/W, RS and E pins). I am using the unbuffered signal generator to generate the signal for E. I want to use the 4bit mode using 4 pins on Port B. These are the problems I am encountering:
1. When I initialize for 4 bit, at the end, looks like there is a data bit F(hex) remaining. So when I send the data, I have to send a dummy low nibble to complete the 8 bit and then use the clear display and return home commands to get rid of this spurious data. For initialize, I am using the sequence published by Samsung which is the same as the one published by Hitachi for HD44780. What is wrong with the initialization procedure for 4bit communication?
2. When I set the address as 'C0' for memory location 40(hex), the data sent after setting this address is not displayed on the second line. The data is overwritten on the first line itself. How should I correct this problem? This is not happening when I use 8bit communication but I need the 4 output pins for other controls.
Please help
Thanks,
Narayanan
