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Section 2

Convert the keypad to work on an analog phone

First off lets have a look at the keypad inside the payphone:
      
    
This keypad was not what I had expected. I had figured it would be a keypad module. Not a mylar pad style attached to the keypad. But the pin mapping was fairly straight forward.

  

ROWS:
Pin1: *,0,#,A,F
Pin2: 9,8,7,B,C,G,H
Pin3: 4,5,6D,E,I,J
Pin4: 1,2,3,Next,Lang,Up,Down

COLUMS:
Pin5: Next,C,E
Pin6: 3,6,9,#
Pin7: Down, G,I
Pin8: A,I,J, Up
Pin9: 1,4,7,*
Pin10: 2,5,8,0
Pin11: B,D,Lang, 

The connector:
Now I have no idea if the pin numbers are correct as its not written on the control board or the connector. But for the purposes of this document it will do.

A few notes.
-The keypad on all Millennium phones appear to have the 10 speed dial buttons, whether you have the right cover or not. If you wanted to you could build your own keypad. 
-The numeric pad follows the standard of rows and columns on most older phones, it just has a few extra buttons. We wont be using these, but you could tie them in to the arduino and actually build an interactive menu and use hotkeys. If you are very ambitious you could use the arduino to operate small solid state relays (so no click sound) and make the arduino do everything from dial to speed dial and occasionally call you just to let you know how great you are. 
We will be using Pins 1,2,3,6,8,19

I pulled apart the keypad and confirmed that it used the standard rows and columns :
  

I built a simple cable to connect the two together:
(This will be different for every phone, not much point in posting the pinout, but because its a multi color wire, I think you can figure it out.)



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