there are two tasks
1. read the key
2. set output on LCD
first can be easily done with proper key at any of the ports and nand all of then to generate the intrrupt...
the second one can be dependent on the type of LCD you are using...
generally depending upon the datasheet provided by the manufacturer..design the easy char first and then go for custom charactors
datasheets are available on google
and all other are also depend upon the controller used...
Re: Question how to interface 8051 with the 4x4 matrix keypa
Hi,
Use one uC 8-bit port and 8-bit LCD connected in 4-bit communication mode. Use 4 output lines to drive LCD bus and keyboard matrix. Read keyboard with 4 input lines. For LCD controll use to additional 2 output lines from another uC port.
This is basic idea to use same 4-bit bus for LCD and 4x4 Keyboard.
You ll get all the information regarding the interface of keypad with Lcd.
Its better to use one nibble of a port to scan the Columns and another nibble to scan the row value...