Telemetrum interface is wrong

[andrewgreenberg]

1. The telemetrum provides a common v_lipo and then pulls the apogee and main lines to ground using an N channel MOSFET. The current v2 recovery board is designed for a common ground and the two lines going high. This MUST be fixed.
2. The Telemetrum constantly checks for a low value resistance between v_lipo and the apogee and main lines. If this voltage falls below 3.2V, then the Telemetrum won't ever arm. In order to "spoof" the Telemetrum into thinking a valid igniter is attached, a resistor should be put across the optoisolator's LED to prevent the LED's forward voltage (1.3 - 1.75V) from triggering the "bad ignitor" levels. This should be tested, but even a high resistance like 1k should do the trick since the Telemetrum uses a 100k / 27k voltage divider to measure that voltage.