Arming with throttle at mid-stick

ArduCopter Copter 4.6
1

I usually arm my copters by using stick positions - throttle stick down and right.

I thought there was a way to arm a copter from a ground control computer with the throttle in mid-stick position. I thought all that was required was setting the PILOT_THR_BHV so that the first bit was on for “feedback from mid stick.”

But this doesn’t seem to work - even with this bit set, I still can’t arm with the throttle in mid-stick position.

Is there another parameter to allow this?

I thought I went through this when I got my first HereLink - and searched this forum to see if there was advice. I couldn’t find any.

I’d appreciate any helpful comments. Thanks!

2

I am curious to hear more about the PILOT_THR_BHV settings.

I had though to change it but it seemed to have no effect.

3

Stick arming is the same with spring center throttle and PILOT_THR_BHV enabled. Use a switch or from GCS Force Arm.

4

I’m trying to use a controller switch to arm - but it won’t because the throttle stick is spring loaded to the center.

Force Arm is possible - but not a good option for my purpose.

My situation is peculiar because I’m using QGC on an Android device with a Logitech Gamepad.

I’m using a switch to arm - which will work - but requires the throttle to be held down first.

Using stick only for arming would be my preference but there’s a quirk with the gamepad. When you move the stick full deflection down and right, it doesn’t go to the full PWM limits on either axis. So the flight controller doesn’t recognize the gesture.

Force Arm is not a good option because I want to make sure other conditions such as a good GPS signal are met.

This is a “budget” setup designed for school projects. A small quad with a SiK radio, an Android phone with a gamepad and SiK radio running QGC. It’s about as inexpensive and simple as I know how to make it.

The gamepad has a lot of useful buttons - about 8. (Mission Planner recognizes one more than QGC for some odd reason.)

I can move forward by holding the throttle stick down when pressing the button to Arm - but for simplicity sake, it would sure be nice to not have to hold the throttle stick down. But maybe it’s a good safety. I guess it’s a trade off.

I’m a bit curious now on what exactly the first bit on PILOT_THR_BHV is doing. What exactly does “feedback from mid stick” mean? Maybe it’s not referring to throttle at all.

Thanks Dave - I appreciate your help!

5

I only use center spring throttle on DJI, I have never used it with Arducopter. But playing around with it some time ago Low Stick will be at MOT_SPIN_ARM and as you raise the throttle it will run at MOT_SPIN_MIN until Mid Throttle (whatever is learned or entered) and then take-off as this is exceeded. Assuming you are in an altitude controlled mode that is. PILOT_THR_BHV,7 is most often suggested.

6

Yes - that’s the setting I’ve adopted on all my quads - PILOT_THR_BHV=7

That’s all three bits set.

But I’m still curious what “feedback from mid stick” is doing. Maybe it was deprecated. Who knows? Maybe someone will peek in the code to find out.

Thanks!

7

It’s doing exactly what I posted. Perhaps the description (feedback) is suggesting something more but there is nothing more there. This feature has operated the same way for years. Since V3.3 in 2015 actually.
From the Wayback machine (IOW the Changelog):
d) TX with sprung throttle can set PILOT_THR_BHV to “1” so motor feedback when landed starts from mid-stick instead of bottom of stick

8

I’ve setup a logitec game pad with Mission Planner to fly an EDU450 via a SiK Radio. I bought the cheapest game pad I was willing to tolerate just to prove a point to some people that you don’t need to buy an expensive radio. (For the sake of anyone reading this in the future: you still need a proper radio for initial flights and tuning) I’ll be the first to say the flying experience with the game pad is miserable. Piloting a drone with a game pad is only slightly more successful than piloting a submarine. But it works so it made my point.

I did the arming from Mission Planner, and you could do the same with QGC. I think because of how the game pad sticks work you can’t physically get to the lower right corner with throttle/yaw for stick arming. I just tried mine and I can’t get the stick position. It’s a limitation of the game pad, so maybe another joystick might work better.

9

Yea, I tried that too. It sucked even with a Rover.

10

I think if the feedback from mid-stick setting is set then you should be able to arm from a button or GCS (not using force arm, just regular arm) with the throttle as high as mid position (e.g. thr doesn’t need to be at zero) but only in semi-autonomous modes (e.g AltHold, Loiter, etc). In stabilize and acro the throttle will need to be at zero

2 Likes
11

Just to be clear, as @dkemxr says, the PILOT_THR_BHV parameter doesn’t change the “gesture” used to arm the vehicle. So it’s still throttle down, yaw right to arm.

1 Like
12

Thanks Randy - that’s exactly right - I just tested on my workbench - arming when “mid-stick” works fine in LOITER, etc. My initial mode is usually STABILIZE - which is why I got the error about throttle not at minimum.

3 Likes