Adding a keypad

[monkeyman3024]

Hello all,

I’ve been looking into one of these for a scenario paintball game and was wondering how I could work in a keypad for an alternate path of disarming the prop. I didn’t see enough open pins to connect one. Anyone have any suggestions?

Looking at some of the keypads out there I would need anywhere from 4 to 7 pins.

Thanks!

[Michael]

Sorry, there’s only one pin left on the microcontroller, so keypad is not possible.

[monkeyman3024]

Would it be possible to re-purpose some of the buttons? I was thinking alarm, hour and minute buttons as ones that I won’t need.

[Michael]

Unfortunately, you need a LOT of pins to read a keypad.
http://nootropicdesign.com/projectlab/2010/04/03/keypad-tutorial/

• This reply was modified 8 years, 7 months ago by Michael.
• This reply was modified 8 years, 7 months ago by Michael.

[IChop]

A quick google search shows there are ways to do this…
http://www.youtube.com/watch?v=URO042VrCKU
http://forum.arduino.cc/index.php?topic=13178.0

[Michael]

Thanks for those links, IChop. Yes with some cleverness and additional components, it could be possible.

[monkeyman3024]

Thank you for that info. I was considering using a second arduino for keypad entry and then pass the information serially but this should help eliminate extra components and power needs!

[monkeyman3024]

This wasn’t difficult at all. I’ll see about posting my results, pictures, and more links tonight.

I used the diagram and schematic to determine which pins I wanted to use then removed the alarm button and soldered a wire to 5V, the 3/4 pin for the keypad input, and 1/2 for the ground.
From there it was just applying one of the single pin guides to create a voltage divider.

After that was completed it was just a matter of modifying the code as to take the keypad input where desired and how to handle it.

If you needed to add more features than just a keypad you could use another micro controller or your preference on hardware and communicate over some communication protocol to allow for many more features to be added. At some point though I feel like it would be beneficial to just make something from scratch than trying to re-purpose the board.

[monkeyman3024]

So the basic information is all here on the Arduino website: http://playground.arduino.cc/Code/OneWireKeyPad

Keypad and resistors on breadboard with an Artuino as a Test

Keypad and resistors soldered to board.

• This reply was modified 8 years, 5 months ago by monkeyman3024.
• This reply was modified 8 years, 5 months ago by monkeyman3024.

[Michael]

Just FYI, we are currently working on a new version of the Defusable Clock that will support a keypad without any extra components. This will be available later this year.

[TDG_BullDog]

Just now saw your response Michael. Looking forward to building another using the new kit when it’s available.

[Author]

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