nus / dart_mavlink Goto Github PK

For routing purposes, it may be required to know if the message has target_system and target_component.
As a solution, nullable fields targetSystem and targetComponent may be added to MavlinkMessage.

Hi,
I came across this issue with data persisting in the text list of statustext messages that come quickly together.

I setup code based on your 'parser' example, but that looks for statustext messages and prints the results.
I then connected Ardupilot SITL and tested by issuing "arm throttle" command in mavproxy.

This results in three statustext messages being sent, the first two in close succession, the last one a few seconds later, three messages shown in wireshark

Timing is as shown:

Using the following code in dart to parse the messages:

parser.stream.listen((MavlinkFrame frm) {
      if (frm.message is Statustext) {
        var st = frm.message as Statustext;
        String toprint = ascii.decode(st.text, allowInvalid: true);
        print('$toprint');
      }
    });

This gives the output:

So it seems like there is some data persistence issue in the lists?
Unless I've done something wrong.

The third message can be cleaned up by detecting the null termination in the list, but the second one has no null termination at the end of the message text

Hey, thanks for this lib,
I was able to make your example run without any issue, but i might be missing something i can't find how to send messages.

Could you help me by providing an example or even show me where i could find those informations ?

Hi, I have found the following issue: A FTP message gets injected with the previous message's excess data:

        test('parse_secondMessage', () async {
            MavlinkParser parser = MavlinkParser(MavlinkDialectCommon());
            final completer = Completer<MavlinkMessage>();
            parser.stream.listen((MavlinkFrame frm) {
                if (frm.message is FileTransferProtocol) {
                  completer.complete(frm.message);
                }
            });
            // a heartbeat followed by a FTP ACK in the same frame:
            List<int> bytes = [253, 28, 0, 0, 149, 1, 1, 30, 0, 0, 43, 196, 233, 0, 159, 76, 89, 189, 119, 113, 38, 61, 42, 28, 211, 63, 128, 224, 101, 56, 160, 47, 44, 187, 80, 14, 229, 184, 100, 205, 253, 19, 0, 0, 150, 1, 1, 110, 0, 0, 0, 1, 1, 4, 0, 0, 128, 6, 3, 0, 0, 0, 0, 0, 0, 68, 65, 80, 77, 171, 119];
            Uint8List rawData = Uint8List.fromList(bytes);
            parser.parse(rawData);
            MavlinkMessage message = await completer.future;
            expect(message, isA<FileTransferProtocol>());
            FileTransferProtocol ftp = message as FileTransferProtocol;
            Uint8List sub = ftp.payload.sublist(0,18)
            expect(sub , equals(Uint8List.fromList([4, 0, 0, 128, 6, 3, 0, 0, 0, 0, 0, 0, 68, 65, 80, 77, 0, 0])));
        });

fails:

Expected: [4, 0, 0, 128, 6, 3, 0, 0, 0, 0, 0, 0, 68, 65, 80, 77, 0, 0]
  Actual: [4, 0, 0, 128, 6, 3, 0, 0, 0, 0, 0, 0, 68, 65, 80, 77, 56, 160]
   Which: at location [16] is <56> instead of <0>

suggestion to fix:

common.dart (commit 4c93f21):

  factory FileTransferProtocol.parse(ByteData data_) {
      ...
      var d = data_.buffer.asUint8List() + List<int>.filled(len, 0);

change to:

  factory FileTransferProtocol.parse(ByteData data_) {
      ...
      var d = data_.buffer.asUint8List(data_.offsetInBytes, data_.lengthInBytes) + List<int>.filled(len, 0);

I am using this below to send the request

var missionParamRequestList = MissionRequestList(
    targetSystem: 1,
    targetComponent: 1,
    missionType: mavMissionTypeMission,
  );
  var frm = MavlinkFrame.v2(1, 1, 1, missionParamRequestList);
  await port?.write(frm.serialize());
  print("sent");

for listening to the parameters i am using this code

dialect = MavlinkDialectCommon();
parser = MavlinkParser(dialect!);

parser?.stream.listen((MavlinkFrame frm) {
  //...
});

decoding message it is showing mavlinkversion as 3

FYI We're modifying the MAVLink XSD validation file in ArduPilot/pymavlink#920 to allow a bitmask value to be declared using the Python exponentiation operator.

This makes it easier to immediately visualize which bit is set by a flag, because you can use the syntax

<entry value="2**15" name="BIT15" />

rather than

<entry value="32768" name=" BIT15" />

This is transparent to mavgen because the parser evaluates the number before creating the generated headers. However it may affect other parsers.
We're not updating the XML yet to allow other parsers time to update.

Any concerns, please raise on ArduPilot/pymavlink#920

Im trying to command a message and I can not make it work. Event the parameter example that comes in the lib.

I do not get the ack.

Trying to arm the drone:

void armVehicle() {
    CommandLong armVehicle = CommandLong(
        param1: 1,
        param2: 0,
        param3: 0,
        param4: 0,
        param5: 0,
        param6: 0,
        param7: 0,
        command: 400,
        targetSystem: 1,
        targetComponent: 1,
        confirmation: 0,
      );
    MavlinkFrame frame = MavlinkFrame.v2(0, 255, 1, armVehicle);
    var _serialized_frame = frame.serialize();

    _socket!.send(_serialized_frame, _socket!.address, _socket!.port);

Im also unable to send the heartbeat to the Px4

Heartbeat heartbeat = Heartbeat(
      customMode: 0,
      type: mavTypeGcs,
      autopilot: mavAutopilotInvalid,
      baseMode: 0, 
      systemStatus: 0, 
      mavlinkVersion: 0
    );
    
    MavlinkFrame frame = MavlinkFrame.v2(0, 255, 1, heartbeat);
    _socket!.send(frame.serialize(), InternetAddress.anyIPv4, 14540);

i am using some thing like this but i am not sure if its working or not

RequestDataStream requestDataStream = RequestDataStream(
      targetSystem: 1,
      targetComponent: 1,
      startStop: 1,
      reqMessageRate: 2,
      reqStreamId: 0,
);
await port?.write(requestDataStream.serialize().buffer.asUint8List());

var paramRequestList = ParamRequestList(
      targetSystem: 1,
      targetComponent: 1,
);
await port?.write(paramRequestList.serialize().buffer.asUint8List());

I am not able to change the mode. Can anyone please help me out how to change the mode.

My code

var changeMode=SetMode(customMode: 216, targetSystem: 1, baseMode: 88); var frm = MavlinkFrame.v1(sequence, systemId, componentId, paramRequestList); socket.send(frm.serialize(), d.address, d.port);

Hello, I just saw this library on the MAVLink website, great work! Do you plan on publishing this library to pub.dev, to make it easier to import?

Bug in setInt8List and setUint8List functions in mavlink_message.dart

Hi there,

I've identified a bug in your code related to the setInt8List and setUint8List functions in the mavlink_message.dart file. The issue is that these functions do not increment the offset, causing all elements to be inserted at the same location. Below is the corrected version of the functions:

static void setInt8List(ByteData data, int offsetByte, List<int> list) {
  int len = list.length;
  for (int i = 0; i < len; i++) {
    data.setInt8(offsetByte + i, list[i]);
  }
}

static void setUint8List(ByteData data, int offsetByte, List<int> list) {
  int len = list.length;
  for (int i = 0; i < len; i++) {
    data.setUint8(offsetByte + i, list[i]);
  }
}

Unfortunately, I'm unable to submit a pull request. Could you please implement these changes, or consider adding me as a contributor so that I can submit the fix?

Thank you!

Hello@nus
I can't figure out the "ParamSet" method...
Can you please write a code example for this method?

Hi.
I am relative new to dart.

Can you please explain how to import this to a main project?