arduino_code_for_foot_pedal_keyboard.c

/*
 * Arduino Keyboard Emulation
 * learnelectronics
 * 13 FEB 2017
 * 
 * www.youtube.com/c/learnelectronics
 */

//#############################################################################################################
//This code only works on an Arduino with the ATmega32U4 chip, so only Arduino Leonardo and Arduino Pro Micro!!
//#############################################################################################################


#include <Keyboard.h>    // This is a "built-in" library no need to install
#include "Keyboard.h"

#define PEDAL1_KEY   '5'   //Change this to define which key to send for each pedal
#define PEDAL2_KEY   '6'
#define PEDAL3_KEY   '7'
#define PEDAL4_KEY   '8'
#define PEDAL5_KEY   '9'

#define PEDAL1_PIN   3    //define input pins for the switches
#define PEDAL2_PIN   4
#define PEDAL3_PIN   5
#define PEDAL4_PIN   6
#define PEDAL5_PIN   7


// Works on the Leonardo board only to simulate 
// a HID keyboard over USB


void setup(void) {
  pinMode(2,INPUT_PULLUP);   //Pin 2 is used as a failsafe, connect it to GND!
  delay(100);


  // Set pin to input
  pinMode(PEDAL1_PIN, INPUT);
  // Enable pullup resistor
  digitalWrite(PEDAL1_PIN, HIGH);

  // Set pin to input
  pinMode(PEDAL2_PIN, INPUT);
  // Enable pullup resistor
  digitalWrite(PEDAL2_PIN, HIGH);

  // Set pin to input
  pinMode(PEDAL3_PIN, INPUT);
  // Enable pullup resistor
  digitalWrite(PEDAL3_PIN, HIGH);

  // Set pin to input
  pinMode(PEDAL4_PIN, INPUT);
  // Enable pullup resistor
  digitalWrite(PEDAL4_PIN, HIGH);

  // Set pin to input
  pinMode(PEDAL5_PIN, INPUT);
  // Enable pullup resistor
  digitalWrite(PEDAL5_PIN, HIGH);


  delay(100);


  if (digitalRead(2) == 0) { //Failsafe 
    Keyboard.begin();
  } else {
    delay(20000);
  }
}

void loop(void) {
  static uint8_t pedal1StateLast = 0;
  static uint8_t pedal2StateLast = 0;
  static uint8_t pedal3StateLast = 0;
  static uint8_t pedal4StateLast = 0;
  static uint8_t pedal5StateLast = 0;

  uint8_t pedalState1;
  uint8_t pedalState2;
  uint8_t pedalState3;
  uint8_t pedalState4;
  uint8_t pedalState5;


  pedalState1 = digitalRead(PEDAL1_PIN);
  if (pedalState1 != pedal1StateLast) {
    pedal1StateLast = pedalState1;

    if (pedalState1 == 0) {
      Keyboard.press(PEDAL1_KEY);
      delay(10);
    } else {
      Keyboard.release(PEDAL1_KEY);
    }
  }

  pedalState2 = digitalRead(PEDAL2_PIN);
  if (pedalState2 != pedal2StateLast) {
    pedal2StateLast = pedalState2;

    if (pedalState2 == 0) {
      Keyboard.press(PEDAL2_KEY);
      delay(10);
    } else {
      Keyboard.release(PEDAL2_KEY);
    }
  }

  pedalState3 = digitalRead(PEDAL3_PIN);
  if (pedalState3 != pedal3StateLast) {
    pedal3StateLast = pedalState3;

    if (pedalState3 == 0) {
      Keyboard.press(PEDAL3_KEY);
      delay(10);
    } else {
      Keyboard.release(PEDAL3_KEY);
    }
  }

  pedalState4 = digitalRead(PEDAL4_PIN);
  if (pedalState4 != pedal4StateLast) {
    pedal4StateLast = pedalState4;

    if (pedalState4 == 0) {
      Keyboard.press(PEDAL4_KEY);
      delay(10);
    } else {
      Keyboard.release(PEDAL4_KEY);
    }
  }

  pedalState5 = digitalRead(PEDAL5_PIN);
  if (pedalState5 != pedal5StateLast) {
    pedal5StateLast = pedalState5;

    if (pedalState5 == 0) {
      Keyboard.press(PEDAL5_KEY);
      delay(10);
    } else {
      Keyboard.release(PEDAL5_KEY);
    }
  }

  delay(50);
}