In a previous post I brought up the subject of cloning: allowing transmitters (and receivers) to configure one another by attaching a serial cable between them. In that post I mentioned the use of a “null modem” cable. The null modem cable would simply swap the RXD and TXD lines running between two connected devices, thereby connecting RXD to TXD, and TXD to RXD and thereby allowing the devices to communicate with one another.
We could, instead, have the transmitter designated as “master” swap its own RXD and TXD internally. Then we could simply use a standard cable for cloning. The processor does not provide a means for swapping RXD and TXD, so this functionality would need to be designed in. It could be accomplished using a 2-channel double-throw analog switch, for example. A binio line on the processor would then control the analog switch.
Designating a transmitter as “master” might be accomplished by holding down the pushbutton switch for five seconds while the transmitter is powered up. A master would swap its own RXD and TXD lines, and then periodically poll for any connected slave devices. Transmitters would, by default, power up configured as slaves. Slave devices will recognize the polling message sent by a master, and upon receiving the polling message will coordinate with the attached master to receive cloning data (clock sync, sport event type, start time, etc.).
It seems that approach would make things very simple for the user, avoid any confusion about cables, and would require a minimum of fuss.