Taranis X9D transmitter and X8R receiver - no PPM

So, the transmitter looks good (although very complicated), but the 2015 model has a hardware and firmware change to make it comply with EU regulation of LBT (listen before transmit). So that's good, but it the only receivers that have also had corresponding firmware upgrades, and so the only ones that work are the X series, e.g. X8R or X6R. These don't support CPPM (which allows all the PWM channels to be transmitted in one wire) and now use a proprietry SBUS format instead. This isn't supported by my quadcopter (or Naze boards in general) so it means I've had to revert to the older wire per channel, each carrying a single PWM signal.

Additionally, the battery voltage telemetry is limited to voltage the receiver gets (which needs to be between 0-5V supplied by the flight control board) and without the external port isn't really of any practical use for determining the voltage level on the battery pack.

S-BUS does look interesting and there are SBUS-to-PPM converters, and the CC3D board does appear to natively support SBUS so I'll probably use that as the starting point when I make my own quad from scratch.

SPORT is the new telemetry interface. Getting my own telemetry data back to the received will be the first homebrew project I attempt (and I might as well start with a level indicator!)