Bolt not applying thrust to one motor, but responsive(?)

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cookies42
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Bolt not applying thrust to one motor, but responsive(?)

Post by cookies42 »

Hello!

I am currently working with the Bitcraze Bolt, and I am emulating the following Bitcraze blog post as closely as possible:

https://www.bitcraze.io/2020/10/testing ... ll-li-ion/

It is going well so far, however, I am having a problem where when trying to take off the drone does not apply any thrust to Motor 4 (M4, front-left) of the drone. It seems to be able to apply uniform thrust to all other motors, however. I switched the working motor and ESC on M3 to be connected to the M4 position and this motor remains unresponsive, leading me to believe this is not an ESC, soldering, or motor issue.

What I found strange is that if I allow the drone to sit turned on, but disconnected from the cfclient, it will eventually go into the beeping sequence (after maybe.... 5minutes of sitting?) where it very slightly twitches each of the four motors as it beeps. During this cycle it is able to move M4 just as much as the other motors, which makes me think everything is connected properly. Any thoughts on why I might not be able to get thrust to my M4 motor for take-off?

I did find a separate recent forum post that was very similar, however they are doing a much larger drone with a single ESC, which I figured was different enough from my application where I am emulating the bolt/li-ion build at the link above which has 4 separate ESCs.

This is the similar & recent forum post: viewtopic.php?f=5&t=4697&p=21487&hilit= ... tor#p21487

Any thoughts or recommendations would be greatly appreciated! I would share a picture but I cannot seem to find how to do so...

Thank you,
Chris
PXL_20210413_195011365_compress.jpg
tobias
Bitcraze
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Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: Bolt not applying thrust to one motor, but responsive(?)

Post by tobias »

That looks very nice, let's try to get it into the air!

Have you been able to check that you get a signal output on M4? I guess that since after 5min M4 actually is starting to run rules out any HW problem with the Bolt.

My guess is that there is some calibration settings issue with the M4 ESC. And this is where it gets tricky since we don't have a BLHeli passthough interface implemented yet. I did build one with a arduino nano to configure my ESCs. Search the internet with "blheli arduino nano" and you will find many guides and I think most arduinos work. The signal range settings for the M4 ESC is probably wrong "PPM Min throttle" and "PPM Max throttle".
cookies42
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Re: Bolt not applying thrust to one motor, but responsive(?)

Post by cookies42 »

Thank you, Tobias!

I have not yet done any calibration of the ESCs, though I had run into some information previously regarding that piece of the puzzle. I'll look into doing this post-haste. Is it possible to do with the motors and connectors already soldered to the ESC? Or is it only possible with an unsoldered ESC?

When I apply thrust to the motors, in cfclient I was able to see "green" output for M1, M2, and M3, but not M4. Not sure if this might help us narrow-down the issues.

Thanks!
-Chris
tobias
Bitcraze
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Joined: Mon Jan 28, 2013 7:17 pm
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Re: Bolt not applying thrust to one motor, but responsive(?)

Post by tobias »

Did you use the connectors so you can unplug the ESC? If so you can connect the ESC to an arduino and program it using BLHelisuite without having to unsolder the ESC.

When you refer to "Green" is that an LED on the ESC? If you unplug the M4 ESC and measure the signal with a multimeter in DC mode it should not show ~0V or ~3.0V but something in between, like ~1.4V if the motor signal output is working correctly.
cookies42
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Joined: Tue Apr 13, 2021 7:36 pm

Re: Bolt not applying thrust to one motor, but responsive(?)

Post by cookies42 »

Hi Tobias,

I did solder the connectors included with the Bolt so that I am able to plug the ESC directly into the Bolt without soldering. The motor is soldered directly to the other side of the ESC. Thanks! I will look into connecting the ESC directly to an arduino. That is helpful.

When I refer to "green" I am referring to the motor column thrust indicators in the cfclient GUI (Thrust, M1, M2, M3, M4). When I apply uniform thrust (up on my control stick), I only see thrust ("green") in M1,M2, and M3. But not M4. I'll include a pic below of where I am referring to in cfclient.

Thanks,
Chris
cookies42
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Re: Bolt not applying thrust to one motor, but responsive(?)

Post by cookies42 »

Bitcraze1.png
tobias
Bitcraze
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Location: Sweden

Re: Bolt not applying thrust to one motor, but responsive(?)

Post by tobias »

Then I suggest measuring the voltage of the M4 signal as I suggested before. I don't know what motor signal protocol you have selected but the default PWM@400Hz should give you a voltage around 1.4V when no throttle is applied. You can also try another protocol like the OneShot125, maybe this will work better with the ESCs.
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