Hello...

I have created a circuit that utilizes an AT89C2051 and a 4-input AND gate to interface with the 4x4 matrix keyboard.

I have tested it and it works great. You can interface it with your micro by using 4-5 i/o lines and a self-made communications protocol. I am currently working on that last detail.

The program for this was written in SDCC and it is very efficient due to using Interrupt technique although a polling technique can also be implemented.

To be honest i use this circuit also to read i-buttons through polling of the specific i/o line.

If you have any questions you can send me an e-mail.