Read and write LVAR

[FrancescoTalotta]

Hello,

thank you for this great project.

I read that with the new version of Simconnect it is possible to read and maybe write LVARs.

Is it possible to read and write LVARs with node-simconnect too?

Thank you

Francesco

[EvenAR]

Hi Francesco! Yes, this is possible with node-simconnect. See #106

Basic example:

const AIRCRAFT_DATA_REQUEST_ID = 0;
const AIRCRAFT_DATA_DEFINITION_ID = 0;

handle.addToDataDefinition(
  AIRCRAFT_DATA_DEFINITION_ID,
  "L:MSATR_MCDU1_MSG_LT",
  null,
  SimConnectDataType.FLOAT64,
  0,
  SimConnectConstants.UNUSED
);

handle.requestDataOnSimObject(
  AIRCRAFT_DATA_REQUEST_ID,
  AIRCRAFT_DATA_DEFINITION_ID,
  SimConnectConstants.OBJECT_ID_USER,
  SimConnectPeriod.ONCE
);

handle.on('simObjectData', function (recvSimObjectData) {
  if (AIRCRAFT_DATA_REQUEST_ID) {
    const lvarValue = recvSimObjectData.data.readFloat64();
    console.log(lvarValue);
  }
});

[FrancescoTalotta]

That’s great, thank you very much. I was wondering whether your implementation could be translated to C. Ideally, my goal would be to make it run on an ESP32. This would allow dedicated hardware to communicate directly with MSFS, eliminating the need for any intermediate driver layer.

[EvenAR]

Cool idea. node-simconnect is basically a TCP client that talks directly with SimConnect, so I'm certain that it’s possible to implement a similar client that runs on ESP32. All you need is a basic TCP client library and the protocol details can be found in the docs I have linked to in the README (and the node-simconnect source code).

[FrancescoTalotta]

That would be great. I am currently working on an ESP32-based board that drives OEM avionics using ARINC 429 signals and communicates with the PC via Ethernet and UDP. Enabling the ESP32 to communicate directly with SimConnect would represent a significant step forward. I will continue working on this and keep you informed. :)