[vc_row][vc_column][vc_column_text]

In the Arduino application system, a keypad is one of the indispensable components for human-computer interface. When the IO resources are rare, we would prefer to use a matrix keypad. In this post, we will show how to use a 4 x4 keypad with Arduino.[/vc_column_text][vc_tour][vc_tab title=”Parts List” tab_id=”1394672966-1-20″][vc_column_text]

• 1 x [bigcommerce link=”/arduino-uno-compatible-usb-board-r3/” target=”_blank”]Arduino UNO[/bigcommerce]
• 1 x 4*4 keypad
• Several jumper wires    
  

[/vc_column_text][/vc_tab][vc_tab title=”Wiring Diagram” tab_id=”1394672966-2-99″][vc_column_text][/vc_column_text][/vc_tab][vc_tab title=”Test code” tab_id=”1394674462264-2-1″][vc_column_text]

#include <Keypad.h>
const byte ROWS = 4;
const byte COLS = 4;

//define the symbols on the buttons of the keypads
char Keys[ROWS][COLS] = 
{
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {2,3,4,5};
byte colPins[COLS] = {6,7,8,9};
//initialize an instance of class NewKeypad
Keypad customKeypad = Keypad(makeKeymap(Keys),rowPins,colPins,ROWS,COLS);

void setup()
{
  Serial.begin(9600);
  Serial.println("Please press the keyboard:");
}

void  loop()
{
  char key = customKeypad.getKey();
  if(key!=NO_KEY)
  {
    Serial.print("Key Value : ");
    Serial.println(key);
  }
}

[/vc_column_text][/vc_tab][vc_tab title=”Run test” tab_id=”1394674463370-3-1″][vc_column_text](1) Hook up everything according to the wiring diagram:

(2) Download the Arduino library in the attachment and save it to the Arduino IDE libraries:

(3)    Open the ArduinoIDE and paste the test code into the IDE, compile and download:

(4)Open the serial Monitor, set the baud rate to 9600, press any key and you will see the corresponding key value in the monitor；

[/vc_column_text][/vc_tab][vc_tab title=”Download” tab_id=”1394674717547-4-4″][vc_column_text]

Arduino Library：keypad

[/vc_column_text][/vc_tab][/vc_tour][/vc_column][/vc_row]