Serial port thermal printer / cash register control for Electron/NodeJS

node_js_serial_port_thermal_printer

const fs = require('fs');
const SerialPort = require('serialport');
const _ = require('lodash');

const BARCODE_TYPES  = {
    upc_a: 0,
    epc_e: 1,
    ean13: 2,
    ean8: 3,
    code39: 4,
    i25: 5,
    codebar: 6,
    code93: 7,
    code128: 8,
    code11: 9,
    msi: 10,
};

let CashRegister = function () {
    console.log(this);
    this.serial_connection = null;

    Object.defineProperties(this, {
        serial_connection: {
            enumerable: true,
            value: this.serial_connection
        }
    });
};

CashRegister.prototype.connect_to_register = function (port) {
    this.serial_connection = new SerialPort(port);
};

CashRegister.prototype.print_barcode = function (data, barcode_type="upc_a", large=true) {
    if (large) {
        this.serial_connection.write([29, 119, 3]);
    } else {
        this.serial_connection.write([29, 119, 2]);
    }

    const printer_code = BARCODE_TYPES[barcode_type];
    const barcode_buffer = Buffer.from(data, 'utf-8');

    this.serial_connection.write([29, 107, printer_code]);
    this.serial_connection.write(barcode_buffer);
    this.serial_connection.write([0]);

    this.new_line();
};

CashRegister.prototype.reset = function () {
    this.serial_connection.write([27, 64]);
};

CashRegister.prototype.indent = function (columns) {
    if (columns < 0 || columns > 31) {
        columns = 0;
    }

    this.serial_connection.write([27, 66, columns]);
};

CashRegister.prototype.set_size = function (width, height) {
    const value = (width * 0xF0) + (height * 0x0F);
    this.serial_connection.write([29, 33, value])
};

CashRegister.prototype.line_feed = function (lines) {
    this.serial_connection.write([27, 100, lines])
};

CashRegister.prototype.set_line_spacing = function (spacing) {
    this.serial_connection.write([27, 51, spacing]);
};

CashRegister.prototype.set_align_left = function () {
    this.serial_connection.write([27, 97, 0])
};

CashRegister.prototype.set_align_center = function () {
    this.serial_connection.write([27, 97, 1])
};

CashRegister.prototype.set_align_right = function () {
    this.serial_connection.write([27, 97, 2])
};
CashRegister.prototype.print_horizontal_line = function (length=32) {
    _.range(length).forEach(() => {
        this.serial_connection.write([196]);
    });
};


CashRegister.prototype.new_line = function () {
    this.serial_connection.write([10]);
};

CashRegister.prototype.open_drawer = function () {
    this.serial_connection.write([27, 112, 0, 25, 250]);
};

export default CashRegister