Keypad - 12 Button (COM-08653 ROHS)

This keypad is a basic 12 button pad that is used for user input. These buttons are setup in matrix format which allows the microcontroller to 'scan' the 7 pins to see which of the 12 buttons are being pressed.

Hello World

Import programInput_Keypad

Sparkfun 12 input keypad that hooks up and is built in a 4X3 matrix form.

Last commit 12 Mar 2015 by Andrew Neville

Library

Import libraryKeyPad

Keypad that has 12 keys for input

Last commit 12 Mar 2015 by Andrew Neville

Notes

/media/uploads/anevil14/08653-03-l.jpg

How The Component Works

The keypad pins correspond to either a certain row or certain column then based on which ones are activated then microcontroller can pick out which button was pressed.

/media/uploads/anevil14/schematic.png

Pin Connections

The Keypad is connected through DigitalIn and DigitalOut pins on the microcontroller and for this we used p21-p27. The schematic is built as follows:

/media/uploads/anevil14/pinconnections.png

Physical Layout

/media/uploads/anevil14/keypad.jpg

Video Demo

Datasheet & Sparkfun Order Page

Datasheet: http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Components/General/SparkfunCOM-08653_Datasheet.pdf

Sparkfun: https://www.sparkfun.com/products/8653

Example Code

Example Code for main.cpp

#include "mbed.h"
#include "KeyPad.h"

/*  DigitalOut columnoneout     ( p25 );    // pin 3 on keypad 
    DigitalOut columntwoout     ( p27 );    // pin 1 on keypad
    DigitalOut columnthreeout   ( p23 );    // pin 5 on keypad

    DigitalIn rowonein          ( p26 );    // pin 2 on keypad 
    DigitalIn rowtwoin          ( p21 );    // pin 7 on keypad
    DigitalIn rowthreein        ( p22 );    // pin 6 on keypad
    DigitalIn rowfourin         ( p24 );    // pin 4 on keypard */

#include <iostream>
int main() {
    Serial pc(USBTX, USBRX); // tx, rx
    KeyPad2 keypad(p25, p27, p23, p26, p21, p22, p24);
    DigitalOut led1(LED1);
    DigitalOut led2(LED2);
    DigitalOut led3(LED3);
    DigitalOut led4(LED4);
    led1 = 0; led2 = 0; led3 = 0; led4= 0;
    pc.printf("starting to print\n");
    while(1) {
        std::vector<int> keys =  keypad.getkey();
        for (int i=0;i<keys.size();i++){
            pc.printf("\nValue:  %d : ",keys[i]);   
            
        }
        wait(.1);
    }
}

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