serialise anki drive message in golang

package main

import (
	"encoding/hex"
	"fmt"
	"reflect"
)

/*
 +---------------------------+--------+--------------+
 | size_of(msg_id + payload) | msg_id | payload(opt) |
 +---------------------------+--------+--------------+
 |        1 byte             | 1 byte | 0-18 bytes   |
 +---------------------------+--------+--------------+
*/
type Message struct {
	Size    byte
	MsgID   byte
	Payload []byte
}

// serialise expect struct. returns message to transmit in bytes.
func serialise(msg interface{}) []byte {
	val := reflect.ValueOf(msg)
	var byteBuf []byte
	// always skip first iteration as its going to be the size.
	for i := 1; i < val.NumField(); i++ {
		byteBuf = append(byteBuf, val.Field(i).Interface().(byte))
	}

	// we pre-pend the size of the msg_id + payload.
	byteBuf = append([]byte{byte(len(byteBuf))}, byteBuf...)

	return byteBuf
}

type AnkiVehicleSdkMode struct {
	Size  byte
	MsgID byte
	On    byte
	Flags byte
}

func main() {

	msg := AnkiVehicleSdkMode{
		Size:  3,
		MsgID: 144,
		On:    1,
		Flags: 1,
	}

	fmt.Printf(hex.Dump(serialise(msg)))
}