TM1637.js

/**
 * Module for display TM1637 on Espruino(Iskra JS)
 * Control a 4 digit led segments TM1637 driver using javascript
 * @code https://github.com/xMlex/TM1637
 * Adaptation from https://github.com/revolunet/tm1637
 */

const codigitToSegment = [
    // XGFEDCBA
    0b00111111, // 0 0x3f
    0b00000110, // 1 0x06
    0b01011011, // 2 0x5b
    0b01001111, // 3 0x4f
    0b01100110, // 4 0x66
    0b01101101, // 5 0x6d
    0b01111101, // 6 0x7d
    0b00000111, // 7 0x07
    0b01111111, // 8 0x7f
    0b01101111, // 9 0x6f
    0b01110111, // A 0x77
    0b01111100, // b 0x7c
    0b00111001, // C 0x39
    0b01011110, // d 0x5e
    0b01111001, // E 0x79
    0b01110001 // F 0x71
];

const ADDR_AUTO = 0x40; // 0b01000000
const STARTADDR = 0xc0; // 0b11000000

function TM1637(clk, dio) {
    this.pinClk = clk;
    this.pinDIO = dio;
    this.trueValue = 1;
    this.q = [];

    // default to HIGH
    this.pinClk.mode('output');
    this.pinDIO.mode('output');
    this.high(this.pinClk);
    this.high(this.pinDIO);
    this.startLoop = this.startLoop.bind(this);
    this.startLoop();
};

TM1637.prototype.startLoop = function () {
    let act = this.q.shift();
    if (act) {
        if (act[0] === "o") {
            act[1].mode('output');
            // console.log("digitalWrite", act);
            digitalWrite(act[1], act[2]);
        } else if (act[0] === "i") {
            act[1].mode('input');
            // console.log("digitalRead", act);
            digitalRead(act[1], act[2]);
        }
    }
    if (this.q.length) {
        setImmediate(this.startLoop);
    }
};

TM1637.prototype.enqueue = function (data) {
    this.q.push(data);
    if (this.q.length === 1) {
        this.startLoop();
    }
};

TM1637.prototype.high = function (pin) {
    this.enqueue(["o", pin, this.trueValue]);
};

TM1637.prototype.low = function (pin) {
    this.enqueue(["o", pin, 1 - this.trueValue]);
};

TM1637.prototype.read = function (pin) {
    let $this = this;
    return new Promise(resolve => $this.enqueue(["i", pin, resolve]));
};

// clock high in, high out
TM1637.prototype.start = function () {
    // pinDIO  high -> low when clock is high
    this.low(this.pinDIO);
};

// clock high in, high out
TM1637.prototype.writeBit = function (value) {
    // A rising edge
    this.low(this.pinClk);
    // change the value when clock is low
    if (value) {
        this.high(this.pinDIO);
    } else {
        this.low(this.pinDIO);
    }

    this.high(this.pinClk);
};

TM1637.prototype.readAck = function () {
    // Falling 8th
    this.low(this.pinClk);
    const readPro = this.read(this.pinDIO);

    // 9th rising edge
    this.high(this.pinClk);

    // Falling 9th
    this.low(this.pinClk);

    return readPro;
};

// clock high in, low out
TM1637.prototype.writeByte = function (byte) {
    // 0b00000000
    let b = byte;
    for (let i = 0; i < 8; i++) {
        this.writeBit(b & 0x01);
        b >>= 1;
    }
    return this.readAck();
};

// clock low in, high out
TM1637.prototype.stop = function () {
    // pinDIO  low -> high  when clock is high
    this.low(this.pinDIO);
    this.high(this.pinClk);
    this.high(this.pinDIO);
};

TM1637.prototype.show = function (str) {
    let numsEncoded = ("" + str)
        .split("")
        .reduce( function (acc, num) {
            if (num === ".") {
                // show point for previous number if needed
                acc[acc.length - 1] |= 0b10000000;
            } else {
                acc.push(codigitToSegment[num] || 0);
            }
            return acc;
        }, [])
        .filter((_, i) => i < 4);

    this.start(); // Data command set
    this.writeByte(ADDR_AUTO); // Normal mode, automatic address increase, write data to the display register
    this.stop();

    this.start(); // Address command setting
    this.writeByte(STARTADDR); // The start of the address starts from 0
    numsEncoded.forEach(this.writeByte.bind(this)); // data
    this.stop();

    this.start(); // Display control
    this.writeByte(0b10001001); // Display control command set, on, brightness 111
    // this.writeByte(ADDR_BRIGHTNESS); // Display control command set, on, brightness 111
    //this.writeByte(ADDR_BRIGHTNESS + ( (brightness & 0x70) | (on? 0x08 : 0x00)  )& 0x0f ); // brightness
    this.stop();
};

exports.TM1637 = TM1637;

exports.connect = function (pinClk, pinDio) {
    return new TM1637(pinClk, pinDio);
};