I have the ServoDecode_pde sketch working with my chepo VEX transmitter. When I attach my scope probe to the ppm pin to view the pulses while it's going to the arduino it switches to Failsafe mode the moment I touch the pin.
Any ideas what would cause this? The scopes input impedance is 1M ohm. Not sure why this would effect anything. I can see the pulses fine on the scope but the arduino goes immediately into failsafe.
Edit:
I just noticed that if I touch the pull-up resistor with my finger it also goes into failsafe mode.... I'm confused!