With the assistance of cgetman02, I've put together a working version of a Moteino based Variometer.
It consists of two subsystems, one, the altimeter function is mounted in the Sailplane and transmits pressure readings to a Moteino based GroundUnit. The GroundUnit converts the pressure and pressure variations into a frequency modulated tone that the RC Sailplane pilot can use to determine rate of climb (or fall).
The main basis for the code is from a blog referenced earlier in this thread, but included here for completeness:
http://www.rcgroups.com/forums/showthread.php?t=1749208The code was used practically unchanged, other than remapping I/O, splitting the function between the two devices, and adding the Moteino radio code.
I've bench tested this. I'll leave it up to cgetman2 to take it flying
Attached are the two schematics and a zip file with the code. Enjoy and, as always, ask questions...
Tom