I have a device that it use an Atmega8 to send some data to a 2*8 character LCD. the LCD has 8 pins and the pins are as below from left to right:
DB7 | DB6 | DB5 | DB4 | En(Clock) | RS | VDD | VFF
I think it is a HD44780 with DB0...3 , Contrast and WR connected to GND.
By the way, I want to monitor the lines between this LCD and Atmega8 using an Atmega32. I mean I want to achieve the data that transferring between them and send it to my computer's COM port and ....
I checked the datasheet of HDD44789 (A 2*16 LCD) and I found this :
Although this has 8 bit for data and mine has 4 bit, but I think both have a single procedure to print data on the LCD.
Now I want to know, how I can read the data on the lines using an Atmega32. for example can I connect En to Interrupt-0 pin and in falling edge read DB4....7? Does it work?
And another question, when we send data to LCD in 4bit-packs, we send high nibble first or we send low nibble?