This is the first (and last) keypad I made not for personal use. It is on a veroboard/perfboard and takes about 5x5 cm. I have used a 4 way connector for the cable towards the ACC port and 8-way pin headers for the keypad. I prefer this latter solution to my development board that uses 8 independent wires.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhGxXdqMMV12aeF9XpShUP6UVLsOLn2uIbzeSMAnGsUCEgdWDze9RDiyvPpgL7Unp9VnRNlea50QMtoWQyt10Q0LWGdMU36IHjZqlRIicpmYUaduuXJLRiTh5aWcIs4OxGrNt86lPPCJ_2b/s320/PC041803.jpg)
This way the keypad sits on top of the circuit, effectively reducing the overall footprint to a bit more than the keypad itself.
For the reset button I installed only two pin headers, if the owner-to-be will feel the need to add one. The LED is wired permanently to the board.
The cable is 1m long, and did not show any communication error during workbench tests.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjVCQsbn_PY8tUJWVKUJ8_dpAQq_OCdtLHPp8jnGDUczVGcLO9sGoDLd4TWZMaoBdLGvcndVgRuur98yOuRC0HD9KbKxmlQWVpTOCNzakTz-W97UAbFFod90pzqGhLmtj0bA61ubxLET00x/s320/PC041800.jpg)
These pictures are provided as a guideline for you, homebrewers out there.
Please note that I am not available for building a keypad for anyone for less than 100 Euro, shipping included, advance payment. I hope this amount is high enough to encourage you into homebuilding this keypad. If you have troubles locating some parts, see the
keypad homepage for some directions.