diff --git a/README.md b/README.md index e2b7cab57..de43b2b9b 100644 --- a/README.md +++ b/README.md @@ -63,6 +63,7 @@ Features: * [events](examples/events/main.go) * [router](examples/router/main.go) * [router-edit](examples/router-edit/main.go) + * [serial-to-json](examples/serial-to-json/main.go) * [stream-requests](examples/stream-requests/main.go) * [readwriter](examples/readwriter/main.go) diff --git a/examples/serial-to-json/main.go b/examples/serial-to-json/main.go new file mode 100644 index 000000000..28f0326be --- /dev/null +++ b/examples/serial-to-json/main.go @@ -0,0 +1,61 @@ +package main + +import ( + "encoding/json" + "flag" + "fmt" + "os" + + "github.com/bluenviron/gomavlib/v2" + "github.com/bluenviron/gomavlib/v2/pkg/dialects/common" + "github.com/bluenviron/gomavlib/v2/pkg/frame" +) + +// this example shows how to: +// 1) create a node which communicates with a serial endpoint +// 2) convert any message to a generic JSON object +// the output of this example can be combined with a JSON parser like jq to display individual messages, for example: +// go run ./examples/serial-to-json | jq 'select(.MessageType == "*minimal.MessageHeartbeat")' + +func main() { + baudRate := flag.Int("b", 57600, "baud rate") + port := flag.String("p", "/dev/ttyUSB0", "port") + flag.Parse() + + // create a node which communicates with a serial endpoint + node, err := gomavlib.NewNode(gomavlib.NodeConf{ + Endpoints: []gomavlib.EndpointConf{ + gomavlib.EndpointSerial{ + Device: *port, + Baud: *baudRate, + }, + }, + Dialect: common.Dialect, + OutVersion: gomavlib.V2, // change to V1 if you're unable to communicate with the target + OutSystemID: 10, + }) + if err != nil { + panic(err) + } + defer node.Close() + + jsonEncoder := json.NewEncoder(os.Stdout) + for evt := range node.Events() { + if frm, ok := evt.(*gomavlib.EventFrame); ok { + // add the message type to the JSON object + if err := jsonEncoder.Encode(struct { + MessageType string + Frame *frame.Frame + }{ + MessageType: fmt.Sprintf("%T", frm.Message()), + Frame: &frm.Frame, + }); err != nil { + // some messages contain floating point NaN values which cannot be encoded in JSON + // silently ignore these errors + if err.Error() != "json: unsupported value: NaN" { + panic(err) + } + } + } + } +}