Keyboard / Keypad interfacing with 8051.
First we need to connect switch as given in figure. So we have now 8 pins that is to be interfaced with microcontroller to detect any of the keystroke. I have simulated this on Proteus. Program has been written in assembly language. You can use Keil to write program and then generate hex file.
This is the snapshot of proteus design. Here i have connected keypad to port 2. You need not to connect resister pack to port 0 if you are not using it. You can see in the figure that a black box has been connected to the Rx and Tx pin. It is virtual terminal used to communicate with computer directly. Here we need to connect it to computer. We will just view the result on this when any key is pressed. You can also use LCD to see the output. I will explain about it in next post.
Click Here to see the assembly language program
