Bluetooth macro keypad

Install first: ESP32 BLE Keyboard (T-vK), ESP32Encoder, Adafruit NeoPixel

#include <BleKeyboard.h>
#include <ESP32Encoder.h>
#include <Adafruit_NeoPixel.h>

BleKeyboard kb("Blueprint Keys", "Blueprint Hardware", 100);
ESP32Encoder knob;
Adafruit_NeoPixel led(1, 4, NEO_GRB + NEO_KHZ800);

const int ROWS[3] = {13, 14, 27};
const int COLS[3] = {32, 33, 25};
const int ENC_SW = 23;

// Each key: modifier + key. Edit to taste.
struct Combo { uint8_t mod; uint8_t key; };
const Combo KEYMAP[3][3] = {
  {{KEY_LEFT_CTRL, 'c'}, {KEY_LEFT_CTRL, 'v'}, {KEY_LEFT_CTRL, 'z'}},
  {{KEY_LEFT_CTRL, 's'}, {KEY_LEFT_CTRL, 'f'}, {KEY_LEFT_ALT, KEY_TAB}},
  {{KEY_LEFT_CTRL, 'd'}, {KEY_LEFT_CTRL, 'e'}, {KEY_LEFT_GUI, 'l'}},  // mute mic, camera, lock
};
bool wasDown[3][3];

void setup() {
  for (int c = 0; c < 3; c++) pinMode(COLS[c], INPUT_PULLUP);
  for (int r = 0; r < 3; r++) { pinMode(ROWS[r], OUTPUT); digitalWrite(ROWS[r], HIGH); }
  pinMode(ENC_SW, INPUT_PULLUP);
  ESP32Encoder::useInternalWeakPullResistors = puType::up;
  knob.attachHalfQuad(18, 19);
  led.begin(); led.setBrightness(40);
  kb.begin();
}

void loop() {
  led.setPixelColor(0, kb.isConnected() ? led.Color(0, 255, 80) : led.Color(0, 80, 255));
  led.show();
  if (!kb.isConnected()) { delay(100); return; }

  for (int r = 0; r < 3; r++) {
    digitalWrite(ROWS[r], LOW);
    delayMicroseconds(30);
    for (int c = 0; c < 3; c++) {
      bool down = digitalRead(COLS[c]) == LOW;
      if (down && !wasDown[r][c]) { kb.press(KEYMAP[r][c].mod); kb.press(KEYMAP[r][c].key); delay(10); kb.releaseAll(); }
      wasDown[r][c] = down;
    }
    digitalWrite(ROWS[r], HIGH);
  }

  long steps = knob.getCount() / 2;
  if (steps) { kb.write(steps > 0 ? KEY_MEDIA_VOLUME_UP : KEY_MEDIA_VOLUME_DOWN); knob.clearCount(); }
  static bool swWas = false; bool sw = digitalRead(ENC_SW) == LOW;
  if (sw && !swWas) kb.write(KEY_MEDIA_MUTE);
  swWas = sw;
  delay(5);
}