Very slow wheels speed after restart in Hovercar mode

[mmaruys]

Variant

HOVERCAR

Control type

FOC

Control mode

Torque

Description

Hi everyone,

For some days I'm trying to solve a problem on my project about wheels going very very slow after firmware update, calibration of the acceleration lever and motherboard restart in Hovercar mode.

I want to use the Hovercar mode, torque mode, right wheel reversed.

So I make the firmware update, on the first start of the mainboard I make the auto calibration and everything works fine but if I restart the board then the wheels are rotating very very slow, like not enough power, like the calibration settings are not the same anymore.

If I reinstall again the firmware, make the first calibration, is ok, but again if I restart it does not work.

VERY IMPORTANT: in ADC mode this problem does not occur, speed is OK after restart. Only in Hovarcar mde I have this problem.

I use this kind of acceleration lever: https://piesetrotinete.ro/wp-content/uploads/2021/10/Maneta-Acceleratie-trotineta-electrice-jpg.webp

Any ideas on how to solve it? or why the speed is becoming very slow after restart in Hovercar mode?

[Candas1]

Hi,

Disable multi-mode

[EFeru]

Candas, what do you say should we disable multi mode by default?

[Candas1]

Hi Emanuel,

Yes I think it makes sense, it can still be documented for people that need it.

[mmaruys]

@Candas1 it works, you’re right, thank you very much! it’s super now. I saw that piece of code and thinking about it for later but never tought that the very slow rotation could be the first mode at such low power. At least if you ask me it could be a good idea to be disabled by default. All the best!

[IerwinDE]

It seems I've ran into the same issue as OP and assume its for the same reason of Multi-mode beeing default after calibration. However I have not found out how to disable that mode yet.

I will dig deeper through the documentation and update here as I think the answere should definetly be here

EDIT: Found it in the commit comments and it is so easy I am ashamed I did not figure it out. Anyway, if someone else comes here with the same issue:

• BEGINNER MODE: Power ON + Brake [released] + Throttle [released or pressed]
• INTERMEDIATE MODE: Power ON + Brake [pressed] + Throttle [released]
• ADVANCED MODE: Power ON + Brake [pressed] + Throttle [pressed]

[Candas1]

adding leading // will comment out this line, thus disabling multimode

[mmaruys]

Hi again, built an electric scooter to move around and works great guys! thanks again for all your study and back engineering. I have one more thing would like to solve about the squizzing sound the motors make when accelerating at maximum, saw somewhere could be connected to current limitation? what do you think?

[Candas1]

That's probably the current chopping. You can try increasing i_dc_max https://github.com/EFeru/hoverboard-firmware-hack-FOC/wiki/Setup-current-and-speed-limits#zap-current-limit

[Candas1]

Please let me know if it works, I'll update this in the wiki

[mmaruys]

I'll try today. Was thinking to increase I_MOT_MAX from 15->20 and I_DC_MAX 17->24 and see how it reacts. Also, what are the recommended maximum limits for these 2 parameters and how can I spot I am in the risk zone? too much heat on the mosfets radiator or on the motors? I guess it's connected with the maximum handle of the mosfets, right? I have a big battery 10s9p (2000mAh cells) and 2 hoverboard battery BMS put in parallel to handle more current, I hope I will not fry the motherboard :))

[Candas1]

The maximum I tried was 25 and 27 I think. Yeah It depends on mosfets, and I am not sure how accurate the current measurement is so I wouldn't go higher than that.

[mmaruys]

Please let me know if it works, I'll update this in the wiki

it’s the same, no change (with I_MOT_MAX from 15->20 and I_DC_MAX 17->24)

[Candas1]

Can you erase before flashing, in case some of those values are stored in eeprom

[mmaruys]

yes, I always erase

[Candas1]

Are you using foc or sinusoidal?

[mmaruys]

FOC

[Candas1]

Can you share a good quality picture of you mainboard?

[mmaruys]

it's the same sound for 2 different mainboards with the same firmware, I have two projects started, as I will be off town for the weekend I will make pictures when come back.

[mmaruys]

Managed to get the pictures today. ![Uploading F1BCD621-7DAD-466A-BA8B-1F3A14E13717.jpeg…]()

[mmaruys]

[mmaruys]

[Candas1]

Ok I thought you could have different shunt resistors but it looks like 2 X R007 as usual