Helder board + battery - GPIO

/* pinouts:
 * A0: analog y axis
 * A1: analog x axis
 * A2: ADC5
 * A3: ADC4
 * A4: ADC1
 * A5: ADC0
 * 9: R1
 * 10: R2
 * 11: L2
 */

#include "HID-Project.h"

#define NUM_BUTTONS 14

#define BTN_UP 0
#define BTN_DOWN 1
#define BTN_LEFT 2
#define BTN_RIGHT 3
#define BTN_A 4
#define BTN_START 5
#define BTN_Y 6
#define BTN_L1 7
#define BTN_X 8
#define BTN_R1 A0
//#define BTN_R1 9
//#define BTN_R2 10
//#define BTN_L2 11
#define BTN_B 12
#define BTN_SELECT 13

const int battPin = A2;
const int chargingPin = A3;
const int chargedPin = A4;
const int shutdownPin = A5;
const int redPin = 9;
const int greenPin = 10;
const int bluePin = 11;
const float lowBattVoltage = 0;    //FIX
const float shutdownVoltage = 0;   //FIX
float voltage;
int charging;
int charged;

void setup() {
  for (int i = 0; i < NUM_BUTTONS; i++) {
    pinMode(i, INPUT_PULLUP);
  }

  pinMode(battPin, INPUT);
  pinMode(chargingPin, INPUT);
  pinMode(chargedPin, INPUT);
  pinMode(shutdownPin, OUTPUT);
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  Serial.begin(9600);

  // Sends a clean report to the host. This is important on any Arduino type.
  Gamepad.begin();
}

void loop() {

  //Battery monitor
  voltage = analogRead(battPin)// * (5.00 / 1023.00);
  Serial.println(voltage);
  charging = digitalRead(chargingPin);
  charged = digitalRead(chargedPin);

  if (voltage <= shutdownVoltage) {
    digitalWrite(shutdownPin, HIGH);
  } else {
    digitalWrite(shutdownPin, LOW);
  }

  if (charged == HIGH) {
    Serial.println("charged");
    analogWrite(redPin, 255);
    analogWrite(greenPin, 255);
    analogWrite(bluePin, 245);
  } else if (charging == LOW) {
    Serial.println("charging");
    analogWrite(redPin, 220);
    analogWrite(greenPin, 218);
    analogWrite(bluePin, 248);
  } else if (voltage <= lowBattVoltage) {
    Serial.println("lowbatt");
    analogWrite(redPin, 245);
    analogWrite(greenPin, 255);
    analogWrite(bluePin, 255);
  } else {
    Serial.println("power");
    analogWrite(redPin, 255);
    analogWrite(greenPin, 245);
    analogWrite(bluePin, 255);
  }

  //Gamepad
  bool down = !digitalRead(BTN_DOWN);
  bool up = !digitalRead(BTN_UP);
  bool left = !digitalRead(BTN_LEFT);
  bool right = !digitalRead(BTN_RIGHT);

  Gamepad.dPad1(GAMEPAD_DPAD_CENTERED);

  if (down) {
    Gamepad.dPad1(GAMEPAD_DPAD_DOWN);
    if (left) {
      Gamepad.dPad1(GAMEPAD_DPAD_DOWN_LEFT);
    } if (right) {
      Gamepad.dPad1(GAMEPAD_DPAD_DOWN_RIGHT);
    }
  } else if (up) {
    Gamepad.dPad1(GAMEPAD_DPAD_UP);
    if (left) {
      Gamepad.dPad1(GAMEPAD_DPAD_UP_LEFT);
    } if (right) {
      Gamepad.dPad1(GAMEPAD_DPAD_UP_RIGHT);
    }
  } else if (left) {
    Gamepad.dPad1(GAMEPAD_DPAD_LEFT);
  } else if (right) {
    Gamepad.dPad1(GAMEPAD_DPAD_RIGHT);
  }

  for (int i = BTN_A; i < NUM_BUTTONS; i++) {
    if (!digitalRead(i)) {
      Gamepad.press(i);
    } else {
      Gamepad.release(i);
    }
  }

  Gamepad.write();
  delay(10);
}