ESP32-C3 6 buttons BLE Keyboard

esp32-ble-ds4-back-x6.ino

// Make sure you can use the ESP32 with the Arduino IDE (Installed esp32 by Espressif in Board Manager).
// Install Lib https://github.com/delfer/ESP32-BLE-Keyboard
// Download the latest release of this library from the release page (Source code (zip)).
// In the Arduino IDE go to "Sketch" -> "Include Library" -> "Add .ZIP Library..." and select the file you just downloaded.

//#define DEBUG_MODE // Uncomment to disable debug output

#ifdef DEBUG_MODE
  #define DEBUG_PRINTF(...) Serial.printf(__VA_ARGS__)
#else
  #define DEBUG_PRINTF(...)
#endif

#include <BleKeyboard.h>

// Create a BleKeyboard object.
BleKeyboard bleKeyboard("ESP32C3-6Keypad", "Delfer", 100);

// --- BUTTON CONFIGURATION ---
// Uncomment the following line to use numpad key codes (KEY_NUM_0..KEY_NUM_5)
// If commented, regular digit keys ('0'..'5') will be used
//#define USE_NUMPAD_KEYS

const int BUTTON_PINS[] = {0, 3, 4, 5, 7, 10};

#ifdef USE_NUMPAD_KEYS
const uint8_t KEY_CODES[] = {
    KEY_NUM_0,
    KEY_NUM_1,
    KEY_NUM_2,
    KEY_NUM_3,
    KEY_NUM_4,
    KEY_NUM_5};
#else
const uint8_t KEY_CODES[] = {
    '0',
    '1',
    '2',
    '3',
    '4',
    '5'};
#endif

const int NUM_BUTTONS = sizeof(BUTTON_PINS) / sizeof(BUTTON_PINS[0]);

// --- DEBOUNCE PARAMETERS ---
// Debounce delay in milliseconds.
const unsigned long DEBOUNCE_DELAY_MS = 50;

// --- STATE VARIABLES FOR POLLING ---
// Last stable (steady) button state
int buttonState[NUM_BUTTONS];
// Last read button state (may be debounced)
int lastButtonState[NUM_BUTTONS];
// Time of last button state change (for debouncing)
unsigned long lastDebounceTime[NUM_BUTTONS] = {0};

void setup() {
#ifdef DEBUG_MODE
  Serial.begin(115200);
#endif

  // Initialize pins
  for (int i = 0; i < NUM_BUTTONS; i++) {
    pinMode(BUTTON_PINS[i], INPUT_PULLUP);
    // Read initial state
    int initialState = digitalRead(BUTTON_PINS[i]);
    buttonState[i] = initialState;
    lastButtonState[i] = initialState;
  }

  bleKeyboard.begin();
  Serial.println("BLE Keyboard started. Waiting for connection...");
}

// -----------------------------------------------------------------
// MAIN LOOP() - BUTTON POLLING WITH DEBOUNCING
// -----------------------------------------------------------------
void loop() {
  // Iterate through all buttons in each cycle
  for (int i = 0; i < NUM_BUTTONS; i++) {
    // 1. Read the current pin state
    int reading = digitalRead(BUTTON_PINS[i]);

    // 2. If the state has changed compared to the previous reading,
    //    reset the debounce timer.
    if (reading != lastButtonState[i]) {
      lastDebounceTime[i] = millis();
    }

    // 3. Check if enough time has passed since the last change.
    if ((millis() - lastDebounceTime[i]) > DEBOUNCE_DELAY_MS) {
      // If enough time has passed, the state can be considered stable.
      // Check if this stable state differs from the previously
      // recorded one.
      if (reading != buttonState[i]) {
        buttonState[i] = reading; // Update stable state

        // 4. Handle press or release event
        if (buttonState[i] == LOW) {
          // EVENT: PRESS (LOW, because INPUT_PULLUP is used)
          DEBUG_PRINTF("✅ Button %d (GPIO%d) PRESSED.\n", i + 1,
                        BUTTON_PINS[i]);
          if (bleKeyboard.isConnected()) {
            bleKeyboard.press(KEY_CODES[i]);
          }
        } else {
          // EVENT: RELEASE (HIGH)
          DEBUG_PRINTF("❌ Button %d (GPIO%d) RELEASED.\n", i + 1,
                        BUTTON_PINS[i]);
          if (bleKeyboard.isConnected()) {
            bleKeyboard.release(KEY_CODES[i]);
          }
        }
      }
    }

    // 5. Save the current read state for the next iteration
    lastButtonState[i] = reading;
  }

  // No delay() in the loop to ensure fast polling and reaction.
}