I have two Diy headtrackers one is configured for 8 & other for 12 both work with an
Ar9x with Multi-module or a Taranis.(just Tryed)
With the Diy_headtracker sketch loaded in Arduino look 4 Config.h page scroll down past the
// -- End of user-configurable parameters.
line to here
// Number of PPM channels out. 1 - 12 channels supported.
#define NUMBER_OF_CHANNELS 8 (change to 12)
save and upload sketch to your headtracker then recalibrate with the GUI.
The GUI cannot configure the amount of channels to output.
This works 4 me hope it is of help.