Lego Duplo Train remote controller using BLE with Espruino and Waveshare Joystick for Micro:bit v2

lego-duplo-train-ble-espruino-microbit.js

/*
Lego Duplo Train BLE remote controller using BLE with Espruino and Waveshare Joystick for Micro:bit v2
(c) 2024 Jerzy Głowacki
MIT License
*/

const SCREEN = {
    READY: "     \n" +
           "     \n" +
           "11111\n" +
           "     \n" +
           "     \n",
    UP_HALF: "     \n" +
             "  1  \n" +
             "11111\n" +
             "     \n" +
             "     \n",
    UP_FULL: "  1  \n" +
             " 111 \n" +
             "11111\n" +
             "     \n" +
             "     \n",
    DOWN_HALF: "     \n" +
               "     \n" +
               "11111\n" +
               "  1  \n" +
               "     \n",
    DOWN_FULL: "     \n" +
               "     \n" +
               "11111\n" +
               " 111 \n" +
               "  1  \n"
};

let JoyStick_P = D8;
let JoyStick_X = D1;
let JoyStick_Y = D2;
let KEY_A = D5;
let KEY_B = D11;
let KEY_C = D15;
let KEY_D = D14;
let KEY_E = D13;
let KEY_F = D12;

pinMode(JoyStick_P, 'input_pullup');
pinMode(KEY_A, 'input_pullup');
pinMode(KEY_B, 'input_pullup');
pinMode(KEY_C, 'input_pullup');
pinMode(KEY_D, 'input_pullup');
pinMode(KEY_E, 'input_pullup');
pinMode(KEY_F, 'input_pullup');

function onKeyPressed(key, cb) {
    let pin;
    if (key == 'P') {
        pin = JoyStick_P;
    } else if (key == 'A') {
        pin = KEY_A;
    } else if (key == 'B') {
        pin = KEY_B;
    } else if (key == 'C') {
        pin = KEY_C;
    } else if (key == 'D') {
        pin = KEY_D;
    } else if (key == 'E') {
        pin = KEY_E;
    } else if (key == 'F') {
        pin = KEY_F;
    }
    setWatch(cb, pin, {
        repeat: true,
        edge: 'falling',
        debounce: 100
    });
}

function debounce(func, timeout = 500) {
  let timer;
  return function(...args) {
    clearTimeout(timer);
    timer = setTimeout(function() { func.apply(this, args); }, timeout);
  };
}

/////////////////////////////////////////////////////////

const devName = "84:72:93:4f:cb:98";
const serviceUUID = "00001623-1212-efde-1623-785feabcd123";
const characteristicUUID = "00001624-1212-efde-1623-785feabcd123";

let gatt;
let char;
let connected = false;
let sending = false;
let lighting = false;

function connectTrain() {
    if (connected) return;
    console.log("Starting connection...");
    return NRF.connect(devName).then(function(g) {
        console.log("Connecting to " + devName);
        gatt = g;
        return gatt.getPrimaryService(serviceUUID);
    }).then(function(service) {
        return service.getCharacteristic(characteristicUUID);
    }).then(function(characteristic) {
        char = characteristic;
        return characteristic.readValue();
    }).then(function() {
        console.log("Train connected");
        connected = true;
    });
}

function disconnectTrain() {
    if (!connected) return;
    return gatt.disconnect().then(function() {
        console.log("Train disconnected");
        connected = false;
    });
}

function sendToTrain(value) {
    if (sending) return;
    sending = true;
    return char.writeValue(new Uint8Array([0x0a, 0x00, 0x41, 0x01, 0x01, 0x01, 0x00, 0x00, 0x00, 0x01])).then(function() {
        return char.writeValue(value);
    }).then(function() {
        sending = false;
    }).catch(function() {
        sending = false;
    });
}

function play(sound) {
    let value;
    if (sound == 'steam') {
        value = 0x0a;
    } else if (sound == 'horn') {
        value = 0x09;
    } else if (sound == 'water') {
        value = 0x07;
    } else if (sound == 'departure') {
        value = 0x05;
    } else if (sound == 'brake') {
        value = 0x03;
    }
    return sendToTrain(new Uint8Array([0x08, 0x00, 0x81, 0x01, 0x11, 0x51, 0x01, value]));
}

function light(isOn) {
    let value = isOn ? 0x0a : 0x00;
    lighting = isOn;
    return sendToTrain(new Uint8Array([0x08, 0x00, 0x81, 0x11, 0x11, 0x51, 0x00, value]));
}

function moveTrain(speed) {
    // speed range: <-0.5, 0.5>
    let value, screen;
    if (speed < -0.4) {
        value = 0x9c;
        screen = SCREEN.DOWN_FULL;
    } else if (speed < -0.3) {
        value = 0xce;
        screen = SCREEN.DOWN_HALF;
    } else if (speed < -0.1) {
        value = 0xe2;
        screen = SCREEN.DOWN_HALF;
    } else if (speed < 0.1) {
        value = 0x00;
        screen = SCREEN.READY;
    } else if (speed < 0.3) {
        value = 0x1e;
        screen = SCREEN.UP_HALF;
    } else if (speed < 0.4) {
        value = 0x32;
        screen = SCREEN.UP_HALF;
    } else {
        value = 0x64;
        screen = SCREEN.UP_FULL;
    }
    show(screen);
    return sendToTrain(new Uint8Array([0x08, 0x00, 0x81, 0x00, 0x01, 0x51, 0x00, value]));
}

function ready() {
    connectTrain().then(function() {
        show(SCREEN.READY);

        onKeyPressed('P', function() {
            console.log('Pressed P');
            play('departure');
        });

        onKeyPressed('A', function() {
            console.log('Pressed A');
            play('break');
        });

        onKeyPressed('B', function() {
            console.log('Pressed B');
            play('departure');
        });

        onKeyPressed('C', function() {
            console.log('Pressed C');
            light(!lighting);
        });

        onKeyPressed('D', function() {
            console.log('Pressed D');
            play('water');
        });

        onKeyPressed('E', function() {
            console.log('Pressed E');
            play('horn');
        });

        onKeyPressed('F', function() {
            console.log('Pressed F');
            play('steam');
        });

        setInterval(function() {
            debounce(moveTrain(analogRead(JoyStick_Y) - 0.5));
        }, 100);
    }).catch(function(e) {
        console.error(e);
        console.log('Retrying...');
        ready();
    });
}

ready();