Motors won't respond to RC throttle

ArduCopter Copter 4.4
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1

I have an old firmware Pixhawk, if i’m reading correctly in the Mission Planner monitor message box, the firmware is a version 2.x. BTW for some reason, the Mission Planner won’t agree to complete downloading newer firmware versions.

It’s an X8 configuration drone.

The radio transmitter is a Devention Devo 7E.

I had everything on the drone running and flying fine until very recently.

But the ESCs, model DYS BLHeli 40A, were old and probably not very high quality and also probably a little underpowered for my motors, in a nutshell, the ESCs started toasting after a nice amount of flying hours of working well.

So i decided to upgrade to APD ESCs of the following model:

Since then, it has been more than 10 days of running around my tail, which i don’t have, but still can’t make the drone functional again.

Initially, been getting from the APD ESCs a 6 beep error sequence, then also a 1 beep with 10 second spacing, been using the following APD troubleshoot page:

Been tweaking around with values of Mission Planner ESC calibration, radio calibration, parameter tree: RC2_ values, RC3_ values, MOT_SPIN values and other values as well, but currently to no avail.

Been changing the ESC protocol from Normal to Dshot150,300,600,1200 and other protocols, in the drop down box in the ESC calibration page, to no avail.

If i do only one ESC calibration and then only one radio calibration in Mission Planner, which does show that all the green bars are indeed moving when i move the RC transmitter stick, then i get the 6 beep sequence from the ESCs, as if the throttle is above 1020uS, and then there is no response from RC transmitter and can’t arm the drone and the Mission Planner motor test won’t work and won’t make the motors spin.

But then, if i don’t do any more ESC calibration or radio calibration and go to the parameter tree and change RC3_MIN from the radio calibrated value of 1085 to 1005 and re-write the parameters, then suddenly there is a sound from the FC, 6 beep sequence stops and 1 beep sequence stars and the motor test stars working, the motors start spinning, but the RC transmitter still won’t respond and won’t arm.

But then, if while still not doing any new ESC or radio calibration, i go to the parameter tree and change the RC3_MIN value back from 1005 to 1085 and re-write the parameters again, motor test still works and if i push the pitch stick (right stick) all the way down and right, i hear an arming sound, but still after the arming sound, the throttle stick won’t make the motors spin.

At this situation, if i do an ESC calibration again, i go back to 6 beeps with nothing responding.

If i change the RC_MIN value to 1100 or above and write the parameters, the motors start spinning immediately.

If i change the MOT_SPIN_ values via parameters tree or via ESC calibration page, it doesn’t seem to affect anything.

What should be my next steps so i can get this drone flying again?

Thanks

2

You might be able to do the firmware update with QGC.
You should do whatever you can to do the firmware update to latest stable. The firmware update should upgrade or convert any parameters as it goes, but save parameters to a file just to be sure (you cant reload them on updated firmware, but you can use them as a reference)

Set the motor type back to PWM for testing, MOT_PWM_TYPE,0
Disable the safety switch, BRD_SAFETYENABLE,0
In MissionPlanner motor test, do some motor tests in there - what happens?
MissionPlanner motor test is the place to get everything working properly before anything else.

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3

In motor test, if i increase the percentage, all 8 motors move faster. If i set the running time to a certain amount of time, all 8 motors run that requested amount of time.

What other tests should i try in motor test to get more clues about the situation?

4

You can do “all in sequence” to ensure they are all activated in the correct order. “A” is front right, “B” is the next one around clockwise, and so on until you get back to front left motor.

Use motor test to find out the minimum reliable percentage where all the motors will operate smoothly. Say it’s 8% as an example.
Set MOT_SPIN_ARM to 0.08
then add a bit, say +0.03, and set MOT_SPIN_MIN to 0.11

If the motor order is correct, and all the props spin in the correct direction it should fly.

Then you can look at using DSHOT and the ESC telemetry/data for driving the harmonic notch filter and general diagnostics as required.

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5

Ok this sounds like the hell i been in trying to config a quadsitter the last few days. even QGC was acting odd doing a motor cal. I finally just did a copter flash in QGC and gave up.

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6

Not all esc’s are 32 bit some are “S” I thinking this could have some issues right now. I could be suffering the same issue with my 4 in 1 esc. the other setting to try is Oneshot

Never buy a esc unless it’s 32bit if you can.

2 Likes
7

i’ve re-flashed the Pixhawk FC firmware and at last the drone is able to arm and all 8 motors are spinning and increase spinning when pushing throttle stick forward.

Now i have a few new problems:

  1. Pixhawk FC will advance from the yellow LED blink and make the ready beep and show the ready blue LED blink, only after i push the safety switch and after much longer time than before. I thought it was because there are no telemetry components on the drone, but anyway i don’t need any GPS at all, so i’ve wholly disabled the GPS via the parameter tree, but still the FC does the same thing.

  2. When pushing the throttle stick forward, the motors do not increase their spinning speed gradually and subtly as was before, but in a much more aggressive fashion, also the same problem when pushing the throttle stick down and decreasing the motor speed, the granularity is too rough, all this is really not good if i’m goin to put the props on.

  3. i chose as an ESC protocol the Dshot 1200, is that a good choice? What should be the reasons to chose one type of protocol and not another?

How can i fix these issues?

Thanks

8

  1. there’s no reason to choose anything more that DHSOT600. DSHOT300 or even 150 is more reliable and more than “fast” enough for anything despite what some small acro quad people might think, and the only reason to stick with 300 or 600 is we’ve seen where some ESCs dont seem to like those lower data rates.

  2. throttle tests on the ground are not definitive in any way - the copter expects to be able to fly when you increase throttle and there will be strange results when it is not able to. MissionPlanner motor test is the only ground-based test that has any real meaning.

  3. Disable the safety switch BRD_SAFETYENABLE,0 Disabling the GPS will basically limit you to Stabilise and AltHold mode. If your flight mode switch was set to Loiter (for example) the copter will never be ready for arming. You miss out on all the good features without a GPS.
    If you do have a GPS I would suggest it be enabled and working.

EDIT:
DSHOT600 seems to fit in nicer with our loop rates too, so it has become the “go to” setting.

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