@signalk/n2k-signalk/utils.js

NMEA 2000 to SignalK conversion library

function chooseField (n2k, field1, field2) {
  let res =
    typeof n2k.fields[field1] === 'undefined'
      ? n2k.fields[field2]
      : n2k.fields[field1]
  // console.log(`chooseField ${typeof n2k.fields[field1]} '${field1}' '${field2}' ${res} ${JSON.stringify(n2k.fields)}`)
  return res
}

function skEngineId (n2k) {
  let id = chooseField(n2k, 'Engine Instance', 'Instance')
  if (typeof id === 'number') {
    return id
  } else {
    return id === 'Single Engine or Dual Engine Port' ? 'port' : 'starboard'
  }
}

function skEngineTitle (n2k) {
  var engine = skEngineId(n2k)
  if (typeof engine === 'number') {
    return engine
  } else {
    return engine.charAt(0).toUpperCase() + engine.slice(1)
  }
}

function acPhase (n2k) {
  const line = n2k.fields['Line']
  if (!line) {
    return 'A'
  } else {
    switch (line) {
      case 'Line 1':
        return 'A'
      case 'Line 2':
        return 'B'
      case 'Line 3':
        return 'C'
      default:
        return 'A'
    }
  }
}

function timeToSeconds (time) {
  if (typeof time !== 'undefined' && time !== null) {
    let split = time.split(':')
    if (split.length === 3) {
      return Number(split[0]) * 3600 + Number(split[1]) * 60 + Number(split[2])
    }
  }
  return null
}

module.exports = {
  chooseField,
  skEngineId,
  skEngineTitle,
  acPhase,
  timeToSeconds
}