shell.js

var readline = require('readline'),
    fs = require('fs'),
    tty = require('tty');

var device = fs.openSync('/dev/ttyO4', 'r+');

var rstream = new tty.ReadStream(device),
    wstream = new tty.WriteStream(device);

rstream.on('data', function (chunk) {
    console.log('Data from device');
    console.log('' + chunk);
});

var cli = readline.createInterface(process.stdin, process.stdout);
cli.prompt();

cli.on('line', function (line) {
    wstream.write(line + '\n');
    cli.prompt();
}).on('end', function () {
    shell.kill();
    console.log('goodbye');
});