Hi Bruce,
I'd like to put forward the GRUVIN9x alternative main PCB board that (as i understand it) replaces the main PCB board on a standard Turnigy 9x Tx.
As i understand it, the good folks behind this project have added significant functionality to the main board in particular to enable Tx integration with various Telemetery capabilities like those found in your favorite FrSky 2.4 DIY kits.
As i presume you're aware - the Gruvin9x branch is part of the ER9x stream of development for the Turnigy 9x devices but has a specific interest in the FrSky Telemetery support. The new board seems to have been bourne out of that line of development. I believe it make a number of the finiky h/w mods that you need to make to a standard Turnigy board to enable Telemetery redundant.
The link i have is as follows:
code.google.com/p/gruvin9x/wiki/PCB
I'd be very interested to see a review of this direction of the opensource activities (should it be consistent with your current endeavours).
THanks
Peter