hi, i have a at89c51 and hd44780 lcd..i want to interface these with each other....i don't have the circuit diagram so please provide me.....
please...........
You will need 8 + 3 ports available -- one for each input/output pin of the LCD. I suggest this to start out. Later you can use a serial in/parallel out shift register to send data to the LCD display. Look for Atmel source codes that involve an LCD screen, most will have the same controller chip as your screen.
u have sent me the simulator..it will help me a lot in understanding the charater display technique....but i want the cirucit diagram of interfacing them....means where the resistor and capacitor will be attached and of what value.....please help me......
Added after 3 minutes:
and i have lcd device named hd44780 which has 8 bit data pine and 3 pns for E,RS,R/W....
Hi there is a lot to understand with the LCD. Take a look here and print this PDF it will be much easier to understand if on paper. https://www.sparkfun.com/datasheets/LCD/GDM1602K-Extended.pdf
Most LCDs are very similar.
The first thing to understand is that you need to select on of two different modes using the RS pin, the correct value you want is listed on the instruction table.
Lets say you want to clear the display, set RS=low, set RW=low, DB7=low DB6=low DB5=low DB4=low DB3= low DB2=low DB1=high
This is called setting up. Once you are done setting up raise the E pin high then back low after a few microseconds (or a millisecond).
The first thing you want to do is enable the display, otherwise writing characters to it and clearing it does nothing. Basically set up your RS, RW, DB7:0 pins then raise E high and bring it low, this will tell the LCD your command is ready. No capacitors or resistors needed (except for contrast pin which is mentioned in the PDF)