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BLHeli32 Dhot300-1200 Arducopter3.6.7- sometimes some engine does not start

(Dimitris Arampatzis) #6

Make again ESC calibration

(jlcortex) #7

I am trying to do throttle calibration, I have tested all possible but it seems ESC do not enter in throttle calibration when signal is Dshot.

I have found this:


“-PPM_Min and PPM_Max are now disabled for DShot, as the end-points are fixed, and ESC calibration isn’t needed anymore
-In Betaflight, min_command and max_throttle are ignored with D-Shot
digital_idle_percent replaces min_throttle
-unsynced_motor_output is removed for DShot as it’s no longer needed”

Could it be detecting the wrong protocol?

(Dimitris Arampatzis) #8

Check on values the min max pwm for ch3

(jlcortex) #9

PWM values of throttle channel coming from the radio is very very near from 1000uS to 2000uS

I repeat than multicopter works perfectly, i am flying with oneshot125, and i can fly with dshot300, dshot300 works almost always. it flies also en dshot1200. I have to re-start several times until all motors spin but then it works perfectly.

In any case I’d like to use dshot1200 because it is digital and it seems to fly ultra-stable. I usually think that these things are hardly noticeable, but in this case I think that it improves a lot.

Are there someone using dshot with no problems?

(S) #10

Yes… 4 arducopters all on dshot300-600. I fly daily. I did have some problems w/ motor starting, but in one case it was a bad esc, and in another it was the blheli-32 settings.
I think in general, my blheli_s esc’s have less issues than the blheli_32 ones… Not sure why.

(Giorgio Rinolfi) #11

Sure, I have more than 30 mini quadcopters and they are all blheli 32 dshot600

(jlcortex) #12

With Arducopter? Last firmware? Can you say me ESC brand/model?

(S) #13

I’m using a couple different Speedix ESC’s, and aikon ak32, and Airbot Ori32.
But like I said before, they’re all 300-600… I haven’t tried 1200. (Not even sure if these ESC’s support that speed).

(jlcortex) #14

ok, i will test a new quad with another ESC model and another pixhawk

(S) #15

One of my speedix esc’s was bad and had the same sort of motor starting issue. But it was always the same output… Front right, in my case… I returned it, and the next one worked fine.

Changing the timing to Auto, and… update rate or something (sorry I dont remember the exact parameter name) in the blheli config also caused motor starting issues for me.

(Filippo Franchini) #16

Hi all, I am a new user and I have the same problem. When I connect the battery and I arm the copter then one or even two motors do not spin and I am running dshot150. It worked perfectly without problems for 2 weeks and then it started to do display the incorrect behavior. I have bad frames on one esc as soon as I connect the pixahwk to blheli suite. As soon as I disconnect it then all motors work fine. I changed from auto timing to 16 degrees and I got the seme issue. I heard that 23 degrees is recommended so I will try this last set up maybe changing also pwm frequency from 48 to 24 khz but I am running out of ideas here. I was wondering if any of you figured out what the problem is. Thank you!

(Peter Hall) #17

try removing the SD card

(Filippo Franchini) #18

Than you for your reply Peter. I tried to erase the EEPROM and reinstall the firmware but nothing. You think the SD card has too many logs? I have 169 logs and some of them are 50 MB… could be that the I just reached a point where the SD card is starting to be too full for the AC3.6.8?

Edit: I just checked and I have a total of 1.8 GB of log files in my SD card, is this too much ?

(Peter Hall) #19

I had this the other week on my octo, I put it down to me messing about in the firmware, I found as the SD card got more logs on it motors were less likely to start. If I removed the SD card they all start every time. Possibly it is a proper bug, as I say try without the SD card, if that fixes we can try and find the bug.

(Filippo Franchini) #20

Hi Peter, this is actually very interesting since it might explain why it worked well for two weeks and then suddenly started to have problem. In the last few weeks I did many long flights and I filled the sd card a lot. I will try to remove the sd and see if the problem persists. If not I guess I should empty my sd card right?
Thank you!

Edit: one thing I forgot to mention is that when I connect my pixhawk 1 to blheli suite via passthrough and I press “read settings”, I am getting many bad mavlink messages such as bad gps, bad gyros, compass variance,… Probably some incompatibility between AC 3.6.8 and blheli32 firmware? However the messages disappear after 5 min or so, they do not seem to be a big issue but anyway I think this might create some troubles during power on ?

(jlcortex) #21

we have to do same test (remove the SD) because we assembly another unit all exactly the same, and it works Ok with dhost. we thought it would be something from that pixhawk unit, but it has not too much sense.

(Filippo Franchini) #22

Hi Peter,

I tried the following with no success.

  • formatted sd card
  • removed sd card
  • changed blheli32 from 32.6 to 32.4
  • tried different blheli suite
  • tried changing from auto to fixed timing 16 and 23 degrees

To me looks like something between AC and blheli. As soon as I connect to BL suite I get many warning messages from AC. If a motor does not spin I have to connect it via usb to blheli suite and then they all spin. The motor is not spinning because it has no power, after 10 min beacon is activated on that motor only and there is no way to make it spin even at 100% throttle. It does not seem this affects flight performance at all but it is indeed annoying and very strange that it worked smoothly for 2 weeks and then it started to show this behavior.
I am using tekko32 holybro escs with dshot150, blheli 32.6, AC 3.6.8 on Pixahawk 1.

Thank you!

Edit: From these experiments I conclude that this is probably not a hardware problem because if it was, then I cannot explain why simply connecting the board to the computer makes all motors spin. The strange messages from AC when I connect via blheli passthrough might indicate some conflicts between AC and blheli?

(Filippo Franchini) #23

The problem persists. I noticed that even when I connect the copter to blheli suite and then I disconnect it, I am not able to fly because I have many warnings from AC such as bad AHRS, gyros still setting, etc. Initially I disconnected the batteries in order to reboot the pixhawk, but this does not work. Mostly one but sometimes 2 motors do not spin. When I perform the motor test in blheli suite all motors always run perfectly. I am running dshot150 on brand new tekko32 escs and I am using a pixhawk 1 with AC 3.6.8 installed. On my copter I have long range mavlink telemetry, frsky passthrough telemetry, FPV equipment with OSD and a cooling fan. IMU load durning flight is 50%, maybe the motor start problem is due to the fact that the board is overloaded?

I also noticed that I have to use an old version of blheli suite in order to connect my escs and read the blheli settings but I do not know if this is related directly to the motor start problem.

My last option is just to reboot the pixhawk from mission planner (after connecting all escs to blheli suite) without having to unplug the batteries. Keeping current to the escs while rebooting AC might solve the issue temporarily.

This is annoying because dshot150 really improved flight time and vibrations on my copter especially under high velocities, and having the telemetry is a great thing that allow to monitor escs health in real time.

Any help is appreciated!

(Filippo Franchini) #24

I tested again and it seems that if I reboot the pixhawk from Mission Planner without unplugging the battery then the motors always start. So maybe it could be related to the fact that when I plug the battery some escs start slightly after the pixhawk sends the dshot frames. If I keep the battery plugged in then all escs are powered and when the pixhawk is rebooted there is no chance that all 4 escs will not receive the frames.

(jlcortex) #25

thats weird! because I did also similar test but the reverse, It you reset the ESC also works, i mean, if you keep the Pixhawk powered (connected to USB) and you do a power reset to the ESCs (disconnect the XT60 and re.plug) then always works.