@pamoja/mavlink

MAVLink v1 and v2 framing, signing, named message fields and enum values, and the mission, command, and offboard protocols. One capability of pamoja, one memory-safe Rust core with bindings for TypeScript, Python, and C#.

Install

npm install @pamoja/mavlink
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This pulls in @pamoja/native, the compiled engine. npm install pamoja is the whole framework in one package.

Example

The test that runs in CI, spliced here as it ran.

From bindings/node/guides/mavlink.ts:

import {
  type MavlinkFrame,
  type MavlinkHeader,
  MavlinkMessage,
  MavlinkParser,
  enumEntry,
  enumNames,
  enumValue,
  fromObject,
  message,
  schemaFor,
} from '@pamoja/mavlink'

const VEHICLE = 1
const AUTOPILOT = 1
const STATION = 255
const PLANNER = 190

// An enum field travels as a number, and the dialect names each number. Printing the name
// keeps a reader from looking up what 2 or 81 means.
const name = (enumeration: string, value: number): string =>
  enumEntry(enumeration, value) ?? String(value)
const header = (systemId: number, componentId: number, sequence: number): MavlinkHeader => ({
  systemId,
  componentId,
  sequence,
})

// Every node broadcasts a heartbeat to say what it is and that it is alive. The frame wraps
// the payload in a header and a checksum seeded with the message's own value.
const heartbeatShape = schemaFor('HEARTBEAT')
const announce = fromObject(heartbeatShape, {
  type: enumValue('MAV_TYPE_GCS'),
  autopilot: enumValue('MAV_AUTOPILOT_INVALID'),
  system_status: enumValue('MAV_STATE_ACTIVE'),
  mavlink_version: 3,
})
const sent = announce.toFrame(header(STATION, PLANNER, 0))
console.log(`sent      ${heartbeatShape.name} in ${sent.bytes.length} bytes`)

// The vehicle answers with its own heartbeat, which reaches the station behind some noise
// and a copy with its last byte flipped in flight.
const vehicle = fromObject(heartbeatShape, {
  type: enumValue('MAV_TYPE_QUADROTOR'),
  autopilot: enumValue('MAV_AUTOPILOT_ARDUPILOTMEGA'),
  base_mode:
    enumValue('MAV_MODE_FLAG_CUSTOM_MODE_ENABLED') |
    enumValue('MAV_MODE_FLAG_STABILIZE_ENABLED') |
    enumValue('MAV_MODE_FLAG_MANUAL_INPUT_ENABLED'),
  system_status: enumValue('MAV_STATE_STANDBY'),
  mavlink_version: 3,
})
const good = vehicle.toFrame(header(VEHICLE, AUTOPILOT, 0))
const garbled = Buffer.from(good.bytes)
garbled[garbled.length - 1] ^= 0xff
const delivered = Buffer.concat([Buffer.from('???'), garbled, good.bytes])

// The parser skips whatever does not start a frame and drops a frame whose checksum fails,
// so only the good copy comes out.
const frames = new MavlinkParser().push(delivered)
console.log(
  `parsed    ${frames.length} frame out of ${delivered.length} bytes,` +
    ' past the noise and the garbled copy',
)
const heard = MavlinkMessage.decode(heartbeatShape, frames[0]!.payload)
console.log(
  `heard     ${name('MAV_TYPE', heard.get('type'))} on` +
    ` ${name('MAV_AUTOPILOT', heard.get('autopilot'))},` +
    ` in ${name('MAV_STATE', heard.get('system_status'))}`,
)

// The base mode is a bitmask, so it names a set of flags rather than one value.
const baseMode = heard.get('base_mode')
console.log(`flags     ${enumNames('MAV_MODE_FLAG', baseMode).join(' | ')}`)
if ((baseMode & enumValue('MAV_MODE_FLAG_SAFETY_ARMED')) === 0) {
  console.log('disarmed  MAV_MODE_FLAG_SAFETY_ARMED is not among them')
}
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The same capability in every language

Documentation

• @pamoja/mavlink reference, every class, function, and type this package exports.
• The MAVLink guide, with the same example in Rust, Python, and C#.
• Every capability, and the install page.

License

MIT