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Rough Motor Running When USB Cable At Vesc Tool is Disconnected

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David Cunliffe
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Rough Motor Running When USB Cable At Vesc Tool is Disconnected

Hi Guys,

I have my motor running on the Vesc MK6 controller and everything works perfectly until I unplug the USB cable on the Vesc.  As soon as I then send a command to turn the motor via CAN the motor oscillates back and forth.  If i plug the USB cable back into the board and connect to my laptop, as soon as the computer "chimes" to recognise the connection the motor returns to normal operation before the Vesc tool is even connected.

Any ideas please!

Thanks in advance.

frank
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How is CAn connected? Only CAN H and CANL? Anything else connected? Do you run it from a battery source?

David Cunliffe
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Hi Frank,

Yes only CAN Hi and Lo are connected and i have a 120R across the bus at each end.  The Vesc is powered from a 48v battery.  My device sending messages via CAN is connected to a +12v bench power supply.  It all works perfectly until unplug the USB cable from the board.

 

DCDAVE

frank
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48V nominal is too much! The max voltage for a fully charged battery should be 51.X Volts. 48 nominal is 54,73 fully charged! That is too close to the 60V rating. Small voltage spikes can take down your unit.

2x 120R is not needed, there is a resistor inside the unit already. 3x 120R is too low. Please take out the resistor and try again. USB should not affect CAN.

You can try with one 220R at the CAN controller side (if that has no resitor buit into it).

 

David Cunliffe
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Hi Frank,

You helped me via a Zoom call last week if you remember - the 48v seems to work Ok.  I have removed the resistor and the result is the same.  When i have the USB connected the system works as it should.  As soon as i unplug the USB the issue occurs.  Is there maybe a different version of Firmware i should try?  I'm currently using Fw 5.3

DCDAVE

frank
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No, the Version is fine, but you could download the latest version again. This is a bit strange. Is the battery discharged a bit?

David Cunliffe
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The battery is sitting at around 50 but is very stable.with no spikes.  You think re-flashing the firmware will do it then?  This is the link you sent me before - is this the correct one to use? . https://vesc-project.com/node/2859

DCDAVE

David Cunliffe
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I've re flashed the firmware with the link in the above post, reloaded the app and motor configs and i get the same situation when i unplug the USB.  You hear the sound from the motor is different from when the USB is connected or not so somehow the configuration seems to change when you unplug the USB.

DCDAVE

frank
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I need to get feedback from Vedder on this issue. Will get back to you on Monday.

David Cunliffe
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Thanks Frank,

I'll drop you an email.

DCDAVE

frank
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What kind of encoder do you run? Hall?

Can you make a video for us?

David Cunliffe
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Have just emailed it to you Frank.

DCDAVE