/*
  Sketch:   sketch.ino
  Created:  25-Feb-2023
  Author:   MicroBeaut
  GitHub:   https://github.com/MicroBeaut/
  Youtube:  https://www.youtube.com/channel/UCAztmS6ogRMH5spdH0bSmEg
*/

/*
Solution For:
Arduino Forum
Topics:   Multi Button Programming
Category: Programming Questions
Link:     https://forum.arduino.cc/t/multi-button-programming/1094488
*/

#define B1 A2  // Button
#define B2 A1  // Button
#define B3 A0  // Button
#define R1 12 // Output relay
#define R2 11 // Output relay
#define R3 10 // Output relay
#define R4 9  // Output relay

#define commonStatusPin R4        // Common Status Pin
const uint8_t numberOfGroup = 3;  // Number Of Group Switch and Relay
const uint8_t buttonPins[] = {B1, B2, B3};  // An array of button pins
const uint8_t relayPins[] = {R1, R2, R3};   // An array of relay pins
bool isActive = false;  // The status for one of the buttons is activated.

void setup() {
  for (uint8_t index = 0; index < numberOfGroup; index ++) {
    pinMode(buttonPins[index], INPUT_PULLUP);
    pinMode(relayPins[index], OUTPUT);
  }
  pinMode(commonStatusPin, OUTPUT);
}

void loop() {
  isActive = false; // Reset
  for (uint8_t index = 0; index < numberOfGroup; index ++) {
    bool value = !digitalRead(buttonPins[index]);
    digitalWrite(relayPins[index], value & !isActive);
    isActive |= value;  // Check if any one of the buttons is activated
  }
  digitalWrite(commonStatusPin, !isActive);
}