dshot, blheli, and setup
« on: June 20, 2017, 03:18:17 am »
at the moment im on LibrePilot-16.09+r273-g50fce72_i686_LP-479_dshot.exe
im using spedix 20a escs with a revo board and tm1806-2300's

my questions are, can I use blheli suite through the revo board? I saw a video with open pilot that allowed you to flash and manipulate each esc but im not able to find those settings.

is LibrePilot-16.09+r273-g50fce72_i686_LP-479_dshot.exe ok for using dshot?

also what would be a good baseline for the esc settings.

thanks

Mateusz

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Re: dshot, blheli, and setup
« Reply #1 on: June 20, 2017, 04:01:22 am »
my questions are, can I use blheli suite through the revo board? I saw a video with open pilot that allowed you to flash and manipulate each esc but im not able to find those settings.

Yes, but not easily and not out of the box at the moment.

History
ESC programming was functional in OpenPilot, but developer who was working on it never finished it such that it could be merged. When fork happened, LibrePilot had no such feature.
That feature shown in OP youtube movie is not very elegant implementation from what I was told, as it requires protocol specific handling, and it would be very hard to maintain, also what some other firmwares do now, which is very inefficient and bloats firmware.

LibrePilot
LP developer coded from scratch just pass-through, leveraging any protocol specific commands to external software (https://bitbucket.org/mindnever/librepilot/branch/soft_serial4). But this work is not merged yet, and you need to know how to compile external git branch. Furthermore, since this was implemented some time ago, and a lot of things has changed in next, this code might need some rewriting and is probably the reason why it's delayed (dev for it busy with other higher priority more interesting tasks as well).

Status
Last time I used it, it worked just fine. I could program littebees 20A escs 4 at once. Though it required enabling something in UAVBrowser, saving, restarting the board. It works, but you need to know how. I do have a programming usb stick though which I recommend getting anyway (they're cheap $1-3 range).

Baseline ESC config
I think most ESCs work just fine with what they're shipped with. The only thing you might want to change is the direction of motors, but you can do that by swapping wires before soldering them, and active barking (dampen light). That's it, everything else default should be fine. Active barking is nice to have when you want more aggressive response for racing, but I wouldn't bother for filming or autonomous aircraft.

is LibrePilot-16.09+r273-g50fce72_i686_LP-479_dshot.exe ok for using dshot?

Current "next" branch which is leading development branch where everything that is ready gets merged, supports DShot on all targets (hardware) and works just fine.

Xviews

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Re: dshot, blheli, and setup
« Reply #2 on: June 20, 2017, 01:12:51 pm »
@Mateusz

Dshot 600 testet and autotune? no Problems? My Motors get very hot with Dshot not with oneshot125..

Mateusz

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Re: dshot, blheli, and setup
« Reply #3 on: June 20, 2017, 01:26:37 pm »
@Mateusz

Dshot 600 testet and autotune? no Problems? My Motors get very hot with Dshot not with oneshot125..

Yeah, no problems with Dshot here. Hot motors sound like problem with Autotune, giving you too high PIDs (I had that once with Yaw PIDs being too high). Don't use Autotune as blackbox, always validate what it estimates. Are the PIDs the same for DShot and Oneshot ? Try to reduce Yaw PIDs by half if they seem to high and see if that helps just for testing if that is the issue.
« Last Edit: June 20, 2017, 01:31:32 pm by Mateusz »

Re: dshot, blheli, and setup
« Reply #4 on: June 20, 2017, 04:15:46 pm »
AutoTune has a setting for that.  DerivativeFactor.  Range is 0 to 1.  Default 0.  Set it to 0.5 will cut D terms in half (and adjust PI to match).

Change System -> Settings -> SystemIdentSettings -> DerivativeFactor and simply "reexport" your PIDs without even flying another tuning flight.  Default way (no smoothquick slider set up) is to toggle FMS into and out of AutoTune mode 3 times.  Else if you have a smoothquick slider, just move it a little (and back to where you like it).

Also reducing the SmoothQuick knob position helps for this.

Re: dshot, blheli, and setup
« Reply #5 on: June 27, 2017, 02:01:47 am »
so ive almost got it my hex flying. it will take off and fly, but when I throttle down a little to come down in altitude the motors just stop, i up the throttle a little and it goes back up. im not sure if i missed something but I cant hover well at all. any thought

Re: dshot, blheli, and setup
« Reply #6 on: June 27, 2017, 07:50:29 am »
Did you change the throttle curve or are you using someone else's config that changed it?  (Input page)  It should be a straight line from lower left to upper right.

Have you calibrated ESCs and set neutrals?

Re: dshot, blheli, and setup
« Reply #7 on: June 27, 2017, 01:24:44 pm »
I did not change the throttle curve, its still a nice straight line :)  I didnt think that I had to calibrate or set neutrals  with dshot?

Re: dshot, blheli, and setup
« Reply #8 on: June 27, 2017, 04:32:16 pm »
I've never used DShot myself.  You could test/set the motor neutrals on the Output page, using DSHot and "test outputs" (props off).  I bet your neutrals are in the middle of the range and they should be at or close to the min for DShot.

Mateusz

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Re: dshot, blheli, and setup
« Reply #9 on: June 27, 2017, 05:16:04 pm »
I did not change the throttle curve, its still a nice straight line :)  I didnt think that I had to calibrate or set neutrals  with dshot?

You dont calibrate dshot, but you set neutrals. Mine are around 40, min is 0 and max is 2000.