DX5e 6-channel radio
AR600 6-channel receiver.
AR600 channel 6 connected to APM channel 8. AR600 channel 5 connected to APM channel 7. APM channel 7 set to mode select. This way I can engage the hardware failsafe to go to manual mode by holding the bind switch, and I can switch between 2 modes with channel 5.
So, I want to know how to set up the failsafe. Ideally I would be able to select between FBW and auto on my ch5 switch, while still having an RTL on signal loss.
Excerpt from AR600 manual:
• Prevents unintentional electric motor response on start-up.
• Establishes low-throttle failsafe if the RF signal is lost.
• The AR600 removes servo output pulses to all channels except the throttle channel during failsafe.
• The AR600 throttle failsafe position is stored via the throttle stick position on the transmitter during binding
So, how do I set up APM to work with this failsafe? How do I ground test failsafe?
Failsafe is a confusing subject, because there are several features called "failsafe". It sounds like you already understand the "hardware failsafe".
To set up the loss of signal failsafe for RTL to this:
I understand now. I would never ever have figured that out. The wiki should to be amended to be more clear and descriptive.
It won't let me set "Position 5" on my mode select switch to anything but "manual."
I already have manual by engaging the hardware failsafe. How do I disable this annoying handholding feature?
I ended up editing the code to allow this. I also looked up FS_LONG_ACTN AND FS_SHORT ACTN. If FS_SHORT_ACTN is set to 1, the aircraft will almost immediately go into RTL mode from auto mode.
If FS_LONG_ACTN is set to 1 and FS_SHORT_ACTN is 0, the aircraft will wait 20 seconds to go to RTL mode from auto mode.
It didn't seem to be switching to circle mode from FBW when I had FS_SHORT_ACTN set to 1, but I haven't flight-tested the failsafe.
If you are using ch8 for mode selection then the hardware mux will put you in manual regardless of what flight mode you assign to position 5. You may think that is annoying but not nearly as annoying as the dev team finds explaining again and again to people why when they assign some mode other than manual to position 5 it goes to manual anyway (by hardware). Consequently it cannot be changed.
Yes, the two parameters (long and short) just determine whether Loiter and Auto modes are disturbed by a failsafe or not. The manual explains that on this page - http://code.google.com/p/ardupilot-mega/wiki/Failsafe
If you find the documentation lacking there is plenty of room on the dev team for anyone wanting to work on it ;)