Step 2: Code
the code is attached, instructables won't let me paste it onto here for some reason...
The code will print the numbers of they keys you pressed, to the COM port.
also, be sure to have the library ''keypad'' in your libraries folder, or this code will not compile.
To use similar, but not equal keypads, just grab your continuity tester, and press those buttons, you will easily find wich pins are for the rows, and wich are for the columns.
IF you need any help, just ask in the comments :)