1824-ADA 3x4 Phone-style Matrix Keypad

1824-ADA 3x4 Phone-style Matrix Keypad

Hey, Jenny, I've got your number! And I'm going to dial 867-5309 into this very nice phone-style matrix keypad. This keypad has 12 buttons, arranged in a telephone-line 3x4 grid. It's made of plastic with sturdy plastic buttons. The keys are connected to a matrix so you only need 7 microcontroller pins (3-columns and 4-rows) to scan through the pad.

There's a great Matrix Keypad Arduino library that should work great with this item with minor adjustments. It's basically a sturdier version of our Membrane 3x4 Matrix Keypad and comes with 7 header pins pre-soldered on for easy plugging. Starting from the left there are three column pins, and then to the right are the four row pins.

• Force: 160-180g
• Contact Resistance: <100Ω
• Weight: 23g

There is a very nice Matrix Keypad Arduino library that works great with this item. The only thing we suggest is to change the initialization code in the examples to this:

#include "Arduino.h"
#include "Keypad.h"
const byte ROWS = 4; //four rows
const byte COLS = 3; //three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};
byte rowPins[ROWS] = {5, 6, 7, 8}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {2, 3, 4}; //connect to the column pinouts of the keypad
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
void setup(){
  Serial.begin(9600);
}
void loop(){
  char key = keypad.getKey();
  if (key != NO_KEY){
    Serial.println(key);
  }
}

This will swap the * and # keys and also let you connect to the Arduino with all the pins in order/in a row starting from digital 2 thru digital 9