code: func (h *HMC6352Driver) Heading() (heading uint16, err error) {
  	if _, err = h.connection.Write([]byte("A")); err != nil {
  		return
  	}
  	buf := []byte{0, 0}
  	bytesRead, err := h.connection.Read(buf)
  	if err != nil {
  		return
  	}
  	if bytesRead == 2 {
  		heading = (uint16(buf[1]) + uint16(buf[0])*256) / 10
  		return
  	}
  
  	err = ErrNotEnoughBytes
  	return
  }
docs: // Heading returns the current heading