M4v2/N4 with external ESC: PWM problems

[saihv]

Hello,

I have an M4 v2 (r1) and N4 combination that I want to use with an external ESC, which is a SimonK based 10 A 4 in 1 ESC. This in turn runs the motors for a QAV 250 sized frame with 5 inch propellers.

The main problem I'm having is an inconsistent PWM signal from the Autoquad. The ESC signal cables are connected to ports 5, 6, 7 and 8 on the N4 with a Quad X configuration, and initially I tried setting the arm PWM ~ 975, minimum to 1100 and maximum to 1800. The motors stop beeping when the Autoquad is armed, but the motors spin randomly when throttle is raised (either only one motor spins, or two spin, usually at a very high speed). Even through tweaking these values around, and/or changing the MOT_VALUE2_A1, A2 and SCAL parameters, there's no improvement. If I monitor the SERVO_OUTPUT data in QGroundControl and raise the throttle, the PWM values of the four motors are unequal and two motors jump to the range of 3000-4000 immediately, and two stay around 1000. I couldn't find any information about how exactly to fine tune the A1, A2 and SCAL parameters, so I was wondering if I could get some suggestions/pointers about what's going wrong and what I can do to fix it?

Thank you very much,
Sai

[aBUGSworstnightmare]

[saihv]

Hi Joerg,

Thanks for the reply. And yes, I made sure I flashed the external ESC firmware. The version that's currently on the board is this: aqv7.1.1852-hwv8.6-ext_esc.zip : for some reason, the "STABLE" link is broken in the firmware wizard so I had to download the "LATEST" one.

I didn't know that the A1, A2 and SCAL were only for QUATOS, that makes sense why they weren't helping. But when it comes to the PWM parameters, I also tried using something like this : ARM 1100, MIN 1150, MAX 1900-2000, and some other values around that, but response was still very much random:

- Not all motors spin, and the ones that spin are at high speeds
- Values in the SERVO_OUTPUT graph going up to 4000
- All four motors have unbalanced outputs

which is why I'm very confused. Am I right in assuming that the SERVO_OUTPUT data is actually the PWM pulse width of the signal generated by the AUTOQUAD?

- Sai

[Max]

[aBUGSworstnightmare]

[JussiH]

Do you have the Vsense wire hooked up?

[saihv]

No, I do not have the Vsense connected yet: would that be a problem?

[LPR]

Sai

Yes that is a problem.

Larry

[JussiH]

Autoquad scales output to battery voltage, so without Vsens line set up you will get drifting Vin resulting in "pulsing" outputs

[Crizz]

I bought a M4 v1.1 with N4 v 1.1 Expander few days ago and have actualy the problem, that i cannot flash other FW tpo the board. When is started it in Bootolader-mode the first time, Windows installed STM32-in-bootloader-driver, and the device is found. But when i try to flash the FW , i get the message

"opening dfu capable device"
"cannot open device"
"Filter on vendor = 0w0483 product = 0xdf11"

what is goint wrong there ? Is it needed to dismount the N4 from the M4 fcu ? I cant hardly believe....

Even VSense is hooked up and i have no selection in QGC for external voltage sensor, how to deal with it ? Any advice ?