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controlling 2 motors for two directions each

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Mon, 2022-06-06 07:17
#1
ori harush
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controlling 2 motors for two directions each

hi

I am making a wheelchair extension that helps move in rough terrains, for that I am using 2 BLDC motors (FLIPSKY 6384) and dual mini FSESC6.7 PRO.

The extension is track based (like a tank), so if I am at full stop and I am turning right I need the left motor to spin forwards and the right motor to spin backwards. It means that I need to be able to drive forwards and backwards and control each motor.

Is it possible?

How can I do that?

 

 

Thanks for the help

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Wed, 2022-06-08 19:16
x78163
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I'm sort of in the same boat.  

My 'solutions' are hacky.  Feed 2x esc's with PPM signals from an Arduino.  Use the arduino to receive remote input, calculate the PPM signal appropriate for each motor and then command the respective ESC.  

"Theoretically" you could use a raspi running VESC-Tool to send command line inputs via python script, with the whole remote decoding and motor calculation thing.  But that is nasty hacky.  

I've reached out to the forum to figure out how to address each motor independently via CANBUS.  Each motor has to have address (for traction control to work), I just don't know the vesc language/methodology well enough to program something via UART to CANBUS.

If the FSESC6.7 can handle dual PPM input and you can disable the CANBUS between the two...then I'd roll with arduino cranking out PPM signals.

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Thu, 2022-06-09 07:35
ori harush
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Thanks, I will use arduino and PPM signal, thats sound good.

I found that manual that may help you too:

https://flipsky.net/blogs/vesc-tool/how-to-control-fsescbase-on-vesc-wit...

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Thu, 2022-06-09 13:57
(Reply to #3)
x78163
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Amazing.  I've seen tons of articles on the PPM control, but that's the first one that included UART with CANBUS communication.  Thank you so much!!!

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Mon, 2022-06-20 17:26
Indy8976
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Hi all!

Same here! I am a computer engineer on a wheelchair (paraplegic from an accident) and was thinking how to make a powerful electric kit to make life easier.

My idea has been the same of x78163: use an Arduino to control via PPM two VESCs.I thought a nunchuk from WII could be used to send commands.

The electronic part should not be difficult:

  1.  Ardunio (even a nano shuould be ok)
  2.  A nunchuk from WII
  3.  Two of FSESC6.7 PRO 70A     ( I have not found a dual VESC that you can control engines independently from PWM  )
  4.  Two motors about 140/160KV
  5.  Battery (36/48V  50A)
  6.  Antispark Switch

My idea is to replicate this kind of propulsion ( I am sorry it is in Italian, I did not found an international page):

https://www.allmobility.it/prodotto/propulsore-simply-to-do/

That is what I have, but it is not very powerful (180W max per motor 775 type whit a planetary ) and even a little uphill can stop it!

So here where I need help:

  1. I have no idea how to attach the motor to the chair in a tough way ( with easy to find items)
  2. Have no idea how to make motors rotate backwards through Ardunio, all examples I have seen they all roll one direction and/or brake ( VESC setup?)

If you have ideas to share or just advices I would be grateful

Of course I still do not have the electronics because I would like have some clear idea about.

Thank you all!

 

 

 

 

 

 

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