4X4 Keypad encoder

Mike2545

I just built a 4X4 serial keypad encoder. Here are a few features:

2400/9600 serial baud rates
Automatic key repeat after delay
Keybeep provides feedback to operator
Low cost (around $15.00)

This uses the E-lab EDE1144 encoder IC, so there is a little programming involved with integrating this with a project, but it is a complete operating module, ready to go! The SERIN command works well with this unit and you can check out the sample code and pictures.




EDIT: I forgot to attach the schematic...

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Mike2545

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Post Edited (Mike2545) : 3/7/2009 4:12:28 PM GMT

Chris Savage

Just as a helpful note for everyone, to prevent your application from hanging up at the SERIN command waiting for a key you can use the Key Ready line to know when to actually stop and receive characters. Back in 2006 I posted some code for dealing with this keypad IC and I am attaching the later one which simulates a security code input. Note also that translation is done automatically for you based on the codes from your keypad so you don’t have to have a bunch of IF...THEN statements to translate the default key codes. I hope this helps. Take care.

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Chris Savage
Parallax Engineering