Pixhawk not working with EMAX 12A SimonK ESC.

[Bill Bonney]

Hi,

Has anybody heard of an issue with SimonK ESCs and Pixhawk where the ESCs fail to work, but work fine without the pixhawk or APM2.x?

I've just had a friend here trying to get his pixhawk to communicate with a http://www.emaxmodel.com/views.asp?hw_id=1434 esc with no luck. After testing the setup with and APM2.6 and direct connection to a D4R-II, which all work as expected. I put the saleae on the PH output and the D4R-II output.

The only difference in the signal is that the Pixhawk goes high for 160ms before valid PWM signal is emitted. Connecting a D4R-II the outputs just starts without the long high pulse. The voltage where all as expected.

Anybody else experience this?

I don’t have any idea what version of SimonK was on the ESC either.

Thanks

Bill

[Philip Rowse]

Yes, lots of talk.  Other than power management issues or bad user setups, we have yet to see a reproducible issue that is actually caused by the Pixhawk.  That being said, one processor, the ATMega8A is I bit fussy on wanting TTL to switch on at around 3v rather than the 1.4v that it should accept.  So if you have not connected your signal ground, it is theoretically possible that you don't get the full 3.3v that the pixhawk is spitting out.

Have a look at the Cargo cult thread here on drones discus, it has lots of opinions, and even some good data :)

I have seen a servo spit it and go full lock with that initial pulse before, that may be worth investigating.

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[Andrew Tridgell]

Hi Bill,

> Has anybody heard of an issue with SimonK ESCs and Pixhawk where the
> ESCs fail to work, but work fine without the pixhawk or APM2.x?

there have been sporadic reports of things like this

> I've just had a friend here trying to get his pixhawk to communicate
> with a http://www.emaxmodel.com/views.asp?hw_id=1434 esc with no
> luck. After testing the setup with and APM2.6 and direct connection to
> a D4R-II, which all work as expected. I put the saleae on the PH
> output and the D4R-II output.

I've just ordered one of those ESCs to see if I can reproduce it

> The only difference in the signal is that the Pixhawk goes high for
> 160ms before valid PWM signal is emitted. Connecting a D4R-II the
> outputs just starts without the long high pulse. The voltage where all
> as expected.

how did you get the voltags on the saleae? Or did you connect a DSO as
well?

If you still have access to the ESC can you please let me know the
following:

1) which output of the Pixhawk were you using? Is the behaviour the
same on all outputs?

2) does the ESC behave the same if it is connected to the PH after the
PH is already outputting the PWM signal? (that would eliminate the
startup pulse as an issue)

3) did you get an oscilloscope trace? One theory about these issues is
it may be that the ESC requires more drive current on the signal pin
than the PH can deliver. That should show up in a comparitive
voltage trace between the PH output and the D4R-II output.

Cheers, Tridge

[Bill Bonney]

Hi Tridge,

I don’t have the ESCs in my possession at the moment, but I can try and get hold of them again. 

I used the Logic Pro in analog mode, not digital so I could see the voltage like a DSO. PH was 0.03V to 3.26V & D4R-II was 0.01V to 3.14V

I have attached two screen grabs showing the startup captures for each of the ESCs, with the interesting timings annotated.

A1) The output used was CH3 AFAIR. I didn’t check each of the channels.

A2) Didn’t try that, but I can. (but when i get the ESC back)

A3) The traces I have are voltage traces, I can send a link to the .logdata files so you can peruse them at your leisure. (they a 1GB each)

Hope that helps :)

Bill

[Bill Bonney]

> On Feb 15, 2015, at 14:42, Philip Rowse <phi...@3drobotics.com> wrote:
>
> Have a look at the Cargo cult thread here on drones discus, it has lots of opinions, and even some good data :)

I’m aware of that, hence I have all the measurements and results from the tests that I did.
But i’m sure it worked better when standing on my left leg only ;-)

bill

[Bill Bonney]

PS: I should add that the ESCs made the initialization sounds with the D4R-II but not when connected to the Pixhawk.

On Feb 15, 2015, at 15:05, Bill Bonney <billb...@communistech.com> wrote:

Hi Tridge,

I don’t have the ESCs in my possession at the moment, but I can try and get hold of them again. 

I used the Logic Pro in analog mode, not digital so I could see the voltage like a DSO. PH was 0.03V to 3.26V & D4R-II was 0.01V to 3.14V

I have attached two screen grabs showing the startup captures for each of the ESCs, with the interesting timings annotated.

A1) The output used was CH3 AFAIR. I didn’t check each of the channels.

A2) Didn’t try that, but I can. (but when i get the ESC back)

A3) The traces I have are voltage traces, I can send a link to the .logdata files so you can peruse them at your leisure. (they a 1GB each)

Hope that helps :)

Bill

<PWMOutD4R.png><PWMOutPixhawk.png>

[Philip Rowse]

But i’m sure it worked better when standing on my left leg only ;-) 

Lol!

Philip Rowse 

Lead Systems Engineer

3DRobotics

Ballarat

Australia

[Jaime Machuca]

I also just came across this information, one of the guys in a Facebook group posted that the pixhawk does not work with the ESCs, even the webpage for the ESCs states that they do not work with the Pixhawk.

http://m.banggood.com/Emax-Simonk-Series-12A-20A-25A-30A-40A-ESC-For-Quadcopter-QAV-250-p-918126.html

Look under product description:

Features:
Based on Simon K firmware, further optimized to perfect drive performance.
Low-voltage protection, over-heat protection and self-check functions.
Separate power supply for MCU and BEC, enhancing the ESC’s ability of eliminating magnetic interference.
Parameters of the ESC can be set via program card or transmitter.
Throttle range can be set to be compatible with different receivers.
Equipped with built-in BEC.
Max speed: 210,000 rpm for 2-pole, 70,000 rpm for 6-pole, 35,000 rpm for 12-pole.

Note: this ESC can not work with pixhawk flight controller.

Jaime Machuca Mercado

CTO | Droidika | www.Droidika.com

Mail. Ja...@Droidika.com

Tel. +52 (33) 3777 5327

Cel. +52 1 (33) 3945 3350

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[john...@gmail.com]

If I remember correctly the PW does has a 900us "initialization" pulse during startup. Since 900us is "out of spec" this could potential confuse a ESC. Another problem is that some ESC's will use the first pulse to define the throttle starting point.

[Andrew Tridgell]

> I used the Logic Pro in analog mode, not digital so I could see the
> voltage like a DSO. PH was 0.03V to 3.26V & D4R-II was 0.01V to 3.14V

I'm jeolous! I only have the Logic16.

> A1) The output used was CH3 AFAIR. I didn’t check each of the channels.
> A2) Didn’t try that, but I can. (but when i get the ESC back)

that would be worth checking I think

> A3) The traces I have are voltage traces, I can send a link to the
> .logdata files so you can peruse them at your leisure. (they a 1GB
> each)

no need - as long as you've confirmed no voltage sag then it should be
good.

meanwhile I'll get some logic traces and see if I can reproduce the
timing you saw.

Cheers, Tridge

[Bill Bonney]

Hi Tridge,

Did you manage to get hold of these ESCs? I’ll request them from the original owner my end and see if we can resolve this issue (sorry, been a bit busy with other things recently)

Thanks

Bill

On Feb 15, 2015, at 15:05, Bill Bonney <billb...@communistech.com> wrote:

Hi Tridge,

I don’t have the ESCs in my possession at the moment, but I can try and get hold of them again. 

I used the Logic Pro in analog mode, not digital so I could see the voltage like a DSO. PH was 0.03V to 3.26V & D4R-II was 0.01V to 3.14V

I have attached two screen grabs showing the startup captures for each of the ESCs, with the interesting timings annotated.

A1) The output used was CH3 AFAIR. I didn’t check each of the channels.

A2) Didn’t try that, but I can. (but when i get the ESC back)

A3) The traces I have are voltage traces, I can send a link to the .logdata files so you can peruse them at your leisure. (they a 1GB each)

Hope that helps :)

Bill

<PWMOutD4R.png><PWMOutPixhawk.png>

[Donatas Montrimas]

Hi all,

Maybe someone knows are Pixhawk works with Turnigy Multistar 20A ESC

Thanks

[Victor Soares]

Does it work with the APM 2.5?

[Paul Atherton]

Not sure about The Turnigy Multistar, but the Turnigy Plush nfet 30a ESC flashed with BLHeli (13.2) does have issues with the Pixhawk (not sure if this is BLHeli specific as have never tested with the stock Turnigy ESC firmware. Often, at least one of the ESCs fails to initialise at powerup (I have BRD_SAFETYENABLE=0 and no safety switch) and will therefore not spin after arming. On occasion, all 4 of my ESCs do the same. Occasionally, they all initialise and I can fly! ;o) In my readings about this issue on another forum, it is being reported as specific to the BLHeli ESC firmware not sure if specifically Silabs specific ESCs or this extends to Amtel also). Incidentally, the ESC reported in the original post, although it is described as SimonK, it is not actually, as its a Silabs chipset (it may be based on SimonK code, but I believe SimonK code is Amtel specific).

[Rajesh Sachdev]

Hi,

I had Turnigy plush 30A ESC's working with Pixhawk, i flashed them with Blheli hoping for better performance and they stopped working with Pixhawk, but they still work with APM so it is Blheli issue for sure. 

...Rajesh

[Bill Bonney]

I think it's Pixhawk. It outputs a long high pulse first before the PWM pulse train. Other controllers do not. This confuses some ESC firmware on startup. Check earlier posts to this thread as I posted the signal timings and levels. I don't have the failing ESCs to test, I only had one for a couple of hours. If somebody sends me one, I could get more data.

Thx

Bill

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[Jesus Alvarez]

Bill.

That info is very clarifying as we have random problems with a Hobbywing Platinum 100A Pro 3 in our aircrafts.

It randomly gets crazy when safety switch is activated and starts beeping. No way to get out of that status but to reset the whole system and try again.

I have thought all this time that the problem was the ESC but maybe is that long pulse from Pixhawk.

[Robert Lefebvre]

Hmmm...  I'm using the HW PP V3 100A on my main test helicopter without issue.  And have used the 50 A units.  And have 8 HW Xrotor 40A's on my Octo, and a number of HW Quattro ESC's with no issue at all.  Of note, I don't use the safety switch on any of my aircraft, so the signal starts coming out much earlier.  Not sure if that's relevant.

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[Bill Bonney]

I’m not saying the Pixhawk doesn’t work, clearly it does. Only some ESCs clearly don’t work. In particular the EMAX 12A ‘SimonK’ ESC. It’s not the levels that are the issue. the only difference I could detect is the long start high pulse from the Pixhawk. The tests I did was with the safety switch disabled.

I’ll see if I can get hold of these ESCs again (The Original owner just converted his 250 racing quad to use Naze instead of PH)