button.cpp

#include "button.h"

#include "constants.h"
#include "logger.h"
#include "bluetooth.h"

namespace button {
  namespace {
    //Stores the value of the button pressed or depressed
    const int8_t BUTTON_NONE = -1;
    volatile int8_t buttonPressed = BUTTON_NONE;

    //Method to call when the the interrupt pin is falling
    void isr() {

      uint8_t button = 0;

      for (int i = 0; i < 8; i++) {

        while (digitalRead(constants::P_BUTTON_CLOCK) == LOW);  //Wait for clock to go high

        button = button + digitalRead(constants::P_BUTTON_DATA);  //If value is high add one

        //If not last time in loop, shift bits
        if (i != 7) {
          button = button << 1;
        }

        while (digitalRead(constants::P_BUTTON_CLOCK) == HIGH);  //Wait for clock to go low
      }
      
      if (button > 64) {  // If button pressed
        buttonPressedCallback(button - 129);
      }
    }
  }

  void buttonPressedCallback(int8_t buttonNumber){
    buttonPressed = buttonNumber;
    bluetooth::sendPacket(bluetooth::C_BUTTON_PRESS + String(buttonPressed));
  }

  //Checks whether the button got pressed
  bool isPressed(uint8_t buttonToCheck) {
    //If not button shield wait two seconds and return true
    if (not constants::IS_BUTTON_SHIELD_CONNECTED  and not constants::IS_DEBUGGING) {
      delay(2000);
      return true;
    }

    //If button pressed is the button to check return true
    if (buttonPressed == buttonToCheck) {
      return true;
    }
    return false;
  }

  void clearLast() {
    buttonPressed = BUTTON_NONE;
  }

  void setup() {
    attachInterrupt(digitalPinToInterrupt(constants::P_BUTTON_INTERRUPT), isr, FALLING); //Attach interrupt for 64 button shield
  }
}