Control Relay By Matrix Keyboard

Introduction
Today, in this experiment, we do a keyboard control relay opening and closing.Press the keys 1 to 8 to control 8 relays separately.Press the key 0 to turn off the 8-way relay.
Components
– 1 * Adeept 2560 Board
– 1 * 8 Channel Relay Module
– 1 *  4*4 Matrix Keyboard
– 8 * Male To Male Jumper Wires
– 8 * Male To Female Jumper Wires

Experimental Principle 
In order to save the resources of the microcontroller port, we usually connect the buttons of the matrix in an actual project.
The following is the schematics of 4×4 matrix keyboard:

In this tutorial, we use the ‘Keypad’ function library. Before programming, please install the library.

This is a 5V 8-channel replay interface board which is able to control various appliance, and other equipments with large current. It can be controlled directly by Microcontroller(Arduino,8051,AVR,PIC,DSP,ARM,MSP430,TTL logic). 5V 8-Channel reply, interface board, and each one needs 15-20mA driver current. It is equipped with high-current relay AC250V 10A also DC30V 10A and screw holes for easy installation.

Experimental Procedures
Step 1: Build the circuit

Step 2: Program controlRelayByMatrixKeyboard.ino

Keypad Library Link:Keypad

/***********************************************************
File name: controlRelayByMatrixKeyboard.ino

Website: www.adeept.com
E-mail: support@adeept.com
Author: Tom
Date: 2017/03/14 
***********************************************************/
#include <Keypad.h>
 
const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
//define the cymbols on the buttons of the keypads
char hexaKeys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {9, 8, 7, 6}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2}; //connect to the column pinouts of the keypad
 
//initialize an instance of class NewKeypad
Keypad customKeypad = Keypad( makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 

const int relayPin1 = 14;
const int relayPin2 = 15;
const int relayPin3 = 16; 
const int relayPin4 = 17; 
const int relayPin5 = 18; 
const int relayPin6 = 19; 
const int relayPin7 = 20; 
const int relayPin8 = 21; 
 
void setup(){
  Serial.begin(9600);//Open serial
  pinMode(relayPin1, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin2, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin3, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin4, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin5, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin6, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin7, OUTPUT); //initialize the relayPin as an output
  pinMode(relayPin8, OUTPUT); //initialize the relayPin as an output
}
   
void loop(){
  char customKey = customKeypad.getKey();//Read Key data   
  if (customKey){
    Serial.println(customKey);          //send the key data by serial port (UART)
  }
  switch(customKey){
    case '0':
          digitalWrite(relayPin1, LOW); //drive relay closure conduction
          digitalWrite(relayPin2, LOW); //drive relay closure conduction
          digitalWrite(relayPin3, LOW); //drive relay closure conduction
          digitalWrite(relayPin4, LOW); //drive relay closure conduction
          digitalWrite(relayPin5, LOW); //drive relay closure conduction
          digitalWrite(relayPin6, LOW); //drive relay closure conduction
          digitalWrite(relayPin7, LOW); //drive relay closure conduction
          digitalWrite(relayPin8, LOW); //drive relay closure conduction
          break;
    case '1':
          digitalWrite(relayPin1, HIGH); //drive relay closure conduction
          break;
    case '2':
          digitalWrite(relayPin2, HIGH); //drive relay closure conduction
          break;
    case '3':
          digitalWrite(relayPin3, HIGH); //drive relay closure conduction
          break;
    case '4':
          digitalWrite(relayPin4, HIGH); //drive relay closure conduction
          break;
    case '5':
          digitalWrite(relayPin5, HIGH); //drive relay closure conduction
          break;
    case '6':
          digitalWrite(relayPin6, HIGH); //drive relay closure conduction
          break;
    case '7':
          digitalWrite(relayPin7, HIGH); //drive relay closure conduction
          break;
    case '8':
          digitalWrite(relayPin8, HIGH); //drive relay closure conduction
          break;
    default: break;   
    }
}

Step 3: Compile and download the sketch to the UNO R3 board.