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Hall sensor response (DRV5056A1)

Posted: Sun Dec 13, 2020 6:31 pm
by mprinz
Hi,
after some days of testing the setup my enthusiasm
Is gone. :(

I use the DRV5056A1 with 3.3V external power and
some 10x3 mm neodymium magnets.

I find it a kind of "noisy" and fast pedal movement leads to
incorrect CC04 values, meaning detecting just - let say - 80 even if the pedal is fully pressed down. On the next hit it detects 127.

Any suggestions?

EDIT: I prepared a video. I thought it is due to the slight rotation of the magnet when pushing down the pedal... but, it rotates always. Hmmm.
https://drive.google.com/file/d/1nlF02b ... sp=sharing

Greetings

Re: Hall sensor response (DRV5056A1)

Posted: Sun Dec 13, 2020 9:06 pm
by mprinz
Another vid showing the calibration and the "noise". I don't know if that's to much fluctuation.. is it?


https://drive.google.com/file/d/1IX2t_1 ... sp=sharing

Re: Hall sensor response (DRV5056A1)

Posted: Sun Dec 13, 2020 11:29 pm
by Rob
It shouldn't be that noisy. Firmware is build 9?

Re: Hall sensor response (DRV5056A1)

Posted: Sun Dec 13, 2020 11:35 pm
by Rob
And it might be necessary to put a capacitor between ground and 3.3v as close as possible to the hall sensor. This is especially true as the distance from the sensor to the supply increases and can also compensate for voltage ripple in modern switch mode power supplies, which are inherently noisy.

Re: Hall sensor response (DRV5056A1)

Posted: Sun Dec 13, 2020 11:49 pm
by Rob
layout.jpg
layout.jpg (186.59 KiB) Viewed 1465 times

Re: Hall sensor response (DRV5056A1)

Posted: Mon Dec 14, 2020 8:25 am
by mprinz
Ah okay.
Yap, I used very long wires to have more space.

And that cap will also solve the problem with the "sticky" CCs?

It's a shame, since I remember that TI graphics from the
documetation...

Thank you!

Regards

Re: Hall sensor response (DRV5056A1)

Posted: Mon Dec 14, 2020 8:33 am
by Rob
In general, any active electronic components need bypass capacitors.

Re: Hall sensor response (DRV5056A1)

Posted: Mon Dec 14, 2020 8:34 am
by mprinz
No, firmware is 1.3.2.8, I downloaded it a few days ago, and had some problems to update.
May it be good to go back to factory settings from time to time.

Is it correct that a device update is only possible with admin rights?

Re: Hall sensor response (DRV5056A1)

Posted: Mon Dec 14, 2020 8:43 am
by Rob
No, you do not need admin privileges. Build 8 is fine though. You don't have any caps? They are pretty common. You could probably salvage some from any old electronics you have kicking around.

Re: Hall sensor response (DRV5056A1)

Posted: Mon Dec 14, 2020 8:55 am
by mprinz
I'll get some caps.

During the last update it crashes in a normal user account.
Using the admin it went through.