TPrinter.js

var Printer = require('thermalprinter');
var Raspi = require("raspi-io");
var five = require("johnny-five");
var board = new five.Board({
    io: new Raspi(),
    port: "/dev/ttyAMA0"
});

board.on('ready', function() {
    var printer = new Printer(board);
    printer.on('ready', function() {
        printer
            .indent(10)
            .horizontalLine(16)
            .bold(true)
            .indent(10)
            .printLine('first line')
            .bold(false)
            .inverse(true)
            .big(true)
            .right()
            .printLine('second line')
            .print(function() {
                console.log('done');
                process.exit();
            });
    });
});