Step-by-step programming 16x2 LCD with 89C51, initialization, frequency requirements

hi, i'm new here.
# i want to know that how to program for a 16/2 lcd display in step by step and what should be the operating frequency of 89c51 for this case.
**# how to initialize the lcd disp
# if the operating freq. is less than 12MHZ is tha possible to interface any more device with same 89c51?

Hi Rathina

1. The operating frequency does not matter, i.e. for a faster frequency you adjust the delays accordingly. I have done
some work on the AT89Cx051 for a 20x4 LCD, but this can also be compiled for a 16x2 and will also run on the
89C51. This circuit runs on an 11.0592MHz crystal - because of baud rates required for serial communication.
(I would be happy to send you the C source files to have a look at/play with, or even post it here. I did this
many years ago and there is definitely some room for improvement, but it can shed some light on your
questions.)

2. I don't quite understand this question. You can interface several LCD devices to a single 89C51. The devices
use an 8 (or 4 bit) databus and hence with some simple interfacing (chip select) you can interface multiple
displays.

Once you have this working, consider adding a temperature sensor and PWM to adjust the LCD contrast depending
on ambient temperature. (Not really necessary for lab work, but if the unit will be used in a real life application, like
outdoors it is very important.)

Have fun!
Pieter.

Dear pieter sir,

thank you very much for your response