MultiKey - One Wire Keypad


Posted on Feb 5, 2014

This project can be used for many different purposes. Probably the most used application would be to interface to any electronic project that requires a keypad. There are several ready made keypads on the market, but those work with matrix connections and require 7 pins for a 12 button pad. For new programmers, matrix keypads can be a bit tricky t


MultiKey - One Wire Keypad
Click here to download the full size of the above Circuit.

o program. My circuit can use from 4 up to 12 push buttons with only one wire connection ( plus ground pin ) making possible to use a small microcontroller like an 8 pin to use this keypad. It`s also built in a setup mode where it`s possible to change the key output rate. This setting is saved in the microcontroller`s memory. Notice that pins 11, 12, 13, 15, 16, 17 and 18 are connected to ground. For each button added just remove the ground connection and connect the pin to a push button and add the resistor the same way as the first buttons.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Audio Millivoltmeter
    Hi-Fi stereo Preamplifier with tone controls
    Light Sequencer Circuit
    Berkeley Bolometer Group - Research
    Speakers
    Water Activated Alarm
    Phone Tap circuit
    100w power amplifier using STK404 integrated circuit



    Top