how to use the channel of serial connection?

[murph12F]

Hello, i am trying to write a little code that will connect via serial and will send some mavlink commands, in the examples i only managed to find how to write once we received something before, since it needs a channel and it seems that in all examples the channel is always took from waiting an event and then using the channel of that event to send back a message, i ll leave a link to an example file to better understand.

https://github.com/bluenviron/gomavlib/blob/main/examples/endpoint-serial/main.go

I want to send an event even without receiving nothing from the serial port, so i guess i have to create a channel, but what i am not understanding is how to use the channel created by the serial connection if it actually creates one, and if not how to properly create a channel. i ll share my draft code.

.....
	node, err := gomavlib.NewNode(gomavlib.NodeConf{
		Endpoints: []gomavlib.EndpointConf{
			gomavlib.EndpointSerial{
				Device: "/dev/ttyUSB0",
				Baud:   57600,
			},
		},
		Dialect:     common.Dialect,
		OutVersion:  gomavlib.V2,
		OutSystemID: 10,
	})
	if err != nil {
		panic(err)
	}
	defer node.Close()

	mex := &common.MessagePositionTargetGlobalInt{
		TimeBootMs:      1234567,
		CoordinateFrame: 2,
		TypeMask:        0,
		LatInt:          512345678,
		LonInt:          -123456789,
		Alt:             150.75,
		Vx:              12.34,
		Vy:              -5.67,
		Vz:              1.23,
		Afx:             0.5,
		Afy:             -0.3,
		Afz:             0.1,
		Yaw:             45.0,
		YawRate:         -0.1,
	}

	//what to put instead of nil to use as channel? 
	node.WriteMessageTo(nil, mex)

}

thank you very much.

[aler9]

Hello, use WriteMessageAll instead of WriteMessageTo.

In case of a serial endpoint, a channel is created automatically. You can obtain it by listening on node.Events() as displayed in all examples. But since there's always one channel, it's useless to store it in the software. Just use WriteMessageAll.