I was wondering what energy efficient protocol should I use for a FSK modulation in a steel conductor. My limitation is on the number of continuous bits I can transmit due to the charging and discharging of the capacitor, and the circuit is battery operated. From my testing I can only transmit a byte at a time with a delay of 200us before a transmission of the next byte.
For a byte communication, the protocol I was considering is to use start, data bits and send it in byte chunks. The packet is going to be fixed length to reduce the packet size. I am not very sure would I need preambles and a stop bit as that would increase the data size, and the start bits and fixed length would determine the start and end of the data transmission.
Paul
Best Answer
This is where formats such as Manchester encoding come in to play. With Manchester encoding, the data is encoded into the transitions and not the levels. Equal numbers of 1s and 0s are always sent, so there is no issue with capacitance getting charged up with a bias of 1s or 0s. Also, clock recovery is simpler since the clock is embedded with the data.