serialport/bin/terminal.js

Node.js package to access serial ports. Linux, OSX and Windows. Welcome your robotic JavaScript overlords. Better yet, program them!

#!/usr/bin/env node

const SerialPort = require('../lib/')
const version = require('../package.json').version
const args = require('commander')
const List = require('prompt-list')

function makeNumber(input) {
  return Number(input)
}

args
  .version(version)
  .usage('[options]')
  .description(
    'A basic terminal interface for communicating over a serial port. Pressing ctrl+c exits.'
  )
  .option('-l --list', 'List available ports then exit')
  .option('-p, --port <port>', 'Path or Name of serial port')
  .option('-b, --baud <baudrate>', 'Baud rate default: 9600', makeNumber, 9600)
  .option('--databits <databits>', 'Data bits default: 8', makeNumber, 8)
  .option('--parity <parity>', 'Parity default: none', 'none')
  .option('--stopbits <bits>', 'Stop bits default: 1', makeNumber, 1)
  // TODO make this on by default
  .option('--echo --localecho', 'Print characters as you type them.')
  .parse(process.argv)

function logErrorAndExit(error) {
  console.error(error)
  process.exit(1)
}

function listPorts() {
  SerialPort.list().then(
    ports => {
      ports.forEach(port => {
        console.log(
          `${port.comName}\t${port.pnpId || ''}\t${port.manufacturer || ''}`
        )
      })
    },
    err => {
      console.error('Error listing ports', err)
    }
  )
}

function askForPort() {
  return SerialPort.list().then(ports => {
    if (ports.length === 0) {
      console.error('No ports detected and none specified')
      process.exit(2)
    }

    const portSelection = new List({
      name: 'serial-port-selection',
      message: 'Select a serial port to open',
      choices: ports.map(
        (port, i) =>
          `[${i + 1}]\t${port.comName}\t${port.pnpId ||
            ''}\t${port.manufacturer || ''}`
      ),
    })

    return portSelection.run().then(answer => {
      const choice = answer.split('\t')[1]
      console.log(`Opening serial port: ${choice}`)
      return choice
    })
  })
}

function createPort(selectedPort) {
  const openOptions = {
    baudRate: args.baud,
    dataBits: args.databits,
    parity: args.parity,
    stopBits: args.stopbits,
  }

  const port = new SerialPort(selectedPort, openOptions)

  process.stdin.resume()
  process.stdin.setRawMode(true)
  process.stdin.on('data', s => {
    if (s[0] === 0x03) {
      port.close()
      process.exit(0)
    }
    if (args.localecho) {
      if (s[0] === 0x0d) {
        process.stdout.write('\n')
      } else {
        process.stdout.write(s)
      }
    }
    port.write(s)
  })

  port.on('data', data => {
    process.stdout.write(data.toString())
  })

  port.on('error', err => {
    console.log('Error', err)
    process.exit(1)
  })
}

if (args.list) {
  listPorts()
} else {
  Promise.resolve(args.port || askForPort())
    .then(createPort)
    .catch(logErrorAndExit)
}