Is there any new coding coming out that will automatically open the gripper function in any Rtl mode, especially Rtl on low battery detection?
Thx
Gary
RTL is a flight mode used for many purposes, and opening a gripper simply because you selected RTL is probably not a reasonable thing.
Do you really mean releasing the gripper as part of a failsafe action? If so, no there is not currently anything in the works to do that and you’re probably the first to bring up the idea. The way to do this would be some new option bits on the FS_OPTIONS parameter. Adding a Payload Jettison option would not be terribly complicated to implement, and this kind of thing is why we made the FS_OPTIONS parameter. It allows additional options to be added easily.
However, I must say I’m a little leary of an option that will jettison a payload onto whatever is located below it at any random time and place due to a low battery. It would certainly be an off-by-default option that the user would have to choose to enable. Therefore any damage or injury would be entirely user enabled. But it is giving the user an option that can result in bad things. Not saying no, not saying yes. Just thinking out loud.
Hi.
Thx for your reply.
We make fishing Drones, which are over water for most of the flight.
Releasing the payload which can be upto 4kg of bait, is a safer option for the drone when the battery has reached a low voltage condition.
So it is really specific to this application.
Thx.
G
Maybe it is possible to achieve something like this via lua scripts?
I have the same need for a different application, pulling a rope. Don’t want to get snagged on RTL and crash.
We are planning to do exactly the same with a GAIA160 Hexacopter. have you found any solution for that?
i have found in the documentation, that FS_Option Bit 5 is “Release Gripper” but it seems not to work
That option is not in the stable release, 4.1.dev only.
Thank you for that information. Do you think i can safely use 4.1dev? This feature is very important for us and i don’t know any workaround…
I cant judge if its safe for you to fly 4.1.dev with no knowledge of your vehicle, setup and mission profile. Obviously there is a stable and a dev branch for a reason. The short term fix is to back port the patch to stable, the longer term is to wait for 4.1 to become stable, that will be a couple of months.
Can LUA scripts detect the flight mode and operate a servo output?
Just checking… I havent followed LUA scripting too closely.
I see there’s these functions:
has_failsafed() - only battery failsafe but close and might be useful
Plus numerous Relay and Servo commands…
For the benifit of myself and people other than iampete 
https://ardupilot.org/copter/docs/common-lua-scripts.html
And example scripts:
Servos yes, but not modes on 4.0. Would be very easy with a script on 4.1.dev, but then you would have the failsafe option anyway.
The 4.0 compatible examples are a much smaller set,
Lots of exciting things in 4.1 
ou yeah, the LED Lua script is something i was looking for a while…
i’ll give 4.1 a try
Tested the Release Griper in Failsafe yesterday, works perfectly.
After turning into Failsafe it hovers for a few seconds, then releases the griper, returned home, deployed landing gear and landed 
1 Like