This instructable will take you through the steps I had to go through to discover the pinout on my keypads, and how I hooked it up to my Raspberry Pi. I'll include the code I'm currently using to "drive" my keypad, and then offer some "next step" type insights into what can be done better, and what could be done next.
Finally, this instructable will really be a sub-instructable that will be part of something I'm calling Voiceberry Pi.
Step 1: Taking a look at what you've got
So, I took a look at the back, saw that there were 10 wires, and three "jumpers" on the outside, but no other indication of how things were wired on the inside. So, I took out the five screws, and looked at the actual circuit board to trace the leads.