I am having trouble getting my signal lost/ throttle failsafe working correctly and hope someone can help me out.
The hardware: Turnigy 9XR radio tx, APM 2.5, Spectrum AR8000 rx, Turnigy dlux 40A SBEC speed controller.
My understanding of the theory and method to set up throttle failsafe with APM 2.5:
1) Set your tx radio up so that the low throttle PWM is below say 950. On my radio I have to turn on extended servo range and adjust my channel one to -125%. this is a low as it will go.
2) Bind to the rx so it sees the throttle at the new low throttle PWM (950) for ESC failsafe.
3) Reset your radio so that low throttle PWM is say 1000. Again on my radio I adjust channel one to -100% but leave the extended range servo on.
4) Calibrate the APM using mission planner to the current tx radio servo range.
To verify failsafe is working, using mission planner, on the failsafe page. Watching the throttle PWM, turn off the tx radio and you should see the throttle PWM go to 950.
My problem is I never see the throttle PWM drop when I turn off the tx radio, and the APM never goes to RTL (understandably). In addition it seems that the servo range calibration does not work correctly as it sets the low throttle PWM to a higher value so the motor runs even when I have the throttle stick all the way down. I can fix this by resetting my tx throttle servo range to -105%.
Am I not doing something incorrectly or do you think something may not be correct on my hardware/radio? Any suggestions?
thanks for your help.