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VESC Questions from the newbie

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mendez
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VESC Questions from the newbie

Hey Guys, I'm new in the forum and I recently purchase a VESC (4.12) and I love it. I have a lot of respect to the creator!

I'm trying to decide if the VESC is a good fit for my application; and I have a few questions:

1. Just to clarify; VESC 6 is compatible with 6V Motors (min)? I can test 2S RC Motors with it?

2. Is there a way to configure the motor via UART?

3. Is there a way to configure the Input Setup via UART?

* I guess I want to be able to configure the motor without using the VESC Tool

4. Is the Firmware Open source?

Thanks a lot guys!
 

 

TheFallen
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1. Not really, 3S and up.
2. Yes, same GUI as the USB/Bluetooth one
3. I guess if you use the UART to send the config settings but you could lock yourself out that way.
Why do you not want to use VESC Tool? It's usually a one time thing.
4. The firmware ought to be: https://github.com/vedderb/bldc

sam.vanratt
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Hi mendez

the VESC 4.12 is not the VESC6 (while they share the same start), you are aware of that I guess.

1) afaik the VESC needs about 10V to start

2) there is a documentation of the language spoken via seriell (VCP) to program the VESC; that could be done while running (well not advised...) The better way is via Bluetooth+Dongle+App

3) see 2)

4) absolutely; that is what the whole project is all about (well Benjamin has to state this); read the Ethos section on this site. There are quite a lot of mods already "on the market" with application specific changes thanks to opensource

 

The VESC6 seems a big step forward in possibilities but a bit of an overkill for RC applications if you want my opinion.

 

Cheers

Sam

Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC

mendez
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Thanks guys for the promptly response. Let me clarify; I intended to use this ESC to control a range of motors for testing on an small inertia dyno; thus, I don't plan on using it for RC cars. Now, I'm trying to find an ESC that can allow me to test a range of motors (2S to 10S) and by the same time understand their electrical characteristics. 

1. VESC 6 uses the DRV8001 and that is why I though you could use 7.4V motors because the DVR min voltage in the datasheet is 6V.
2. It looks like I can do 2S if I use VESC Mini then?
3. Because my application is for motor testing using a dyno; I need to swap motors constantly; thus I need to configure the VESC for every motor. Where can I find more information about motor and input configurations via UART using an Arduino? I saw a Github file for just reading live information but not for changing the settings.

Thanks!

sam.vanratt
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Hi mendez

the driver alone is just a part in the chain. The VESC is validated from 8-60V operation (according to the docu). As the FETs needs a certain voltage differential (which doesn't say anything about your special VESC, as if thirdparty build they could use different FETs with different specs) to have their RDSon available. I've not looked into the circuit diagram, but I'm sure there's a reason why 8V is the minimum.

When I tried in my very small lab to get my VESC (4.12) to run, 5,2V was not enough to even boot the uC, while it operates with 3,3V (after a SPS of course with a minimum Vin).

Ben is surely the one to answer the why, maybe Frank as well.

You could of course trim the parts to operate at low voltage, building a custom VESC for low voltage.

 

As alternative: have you looked into ST or National offering for evaluation boards. Some build their uC with a BLDC driver and leave a lot of specs open. As you get a software and testing suite with it it might give you the same freedom, while having a testlab instead of a programmable ESC like the VESC. The VCP is described by ST on their STM032 website. I guess the VESC description what register/value is controlling what function is mainly in the source code, but again Benjamin might be a better source. Mabye he see's a value in your project and helps you to have in return a gain on his project. Bribing with money might help as well ;-)

Cheers

Sam

Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC

mendez
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Hi Sam,

Thanks for your help!!. I will check the VCP; and also contact Ben. 

Here is why I was confused: I found in Trampa the following VESC 6 Specs:

Technical Data Sheet
- Voltage: 6V – 60V (Safe for 3S to 12S LiPo).
- Voltage spikes may not exceed 60V!
- Current: Continuous 80A, Burst 120A.  Values depend on the temperature and air circulation around the device!
- 5V 1A output for external electronics
- 3.3V 0,5A output for external electronics
...................................and more

 

Now; 1S = 3.7Volts; thus 3S = 11.1V. This is why I'm confused; the specs for VESC 6 shows 6Vmin; but "Safe for 3S.." Why then they say 6V min? Do you understand my confusion?

 

 

sam.vanratt
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Hi mendez

I'd not talk about Trampa, or how they do their specs (remember: the VESC is open source so there are a lot of variants possible all under the hood of VESC), but the voltage is normally absolute, while the 3S could mean a lot depending on the cell chemistry and the range of empty/full.

LTO ranges from 2.2-2.5V

LFP from 2.5-3,7V

LiMn from 2.5-4.2V (often called LiIon)

LiCr from 2.7-4.2V (often called LiIon)

LiPo from 3,1-4.2V

so 3S4P just says about the cell connection, but quite less about the voltage/amperage as long as you do not know the chemistry as well. Most mean LiIon/LiPo but as the operating voltage means it should work fully charged just as safe as fully discharged. I'd not tell anything about the VESC6, as I've not seen the schematics, but maybe Benjamin changed the startup voltage.

Cheers

Sam

 

 

Cheers

Sam

Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC

mendez
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Hi Sam,

I understand your point now. Thanks a lot for your help! 

mendez
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Hey Guys,

I'm trying to understand the VESC 6 Schematic and can anyone tell me what is U11? Is it a switch?

sam.vanratt
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Hi

(as I've no schematic at hand) U normally mean passive parts like a switch. There are only three points where a switch 'd make sense:

a) SoftPower ON function, so a fixed on/off switch (AFAIK not implemented yet by Ben)

b) HALL/SENSOR/Temp Voltage selection=two way switch or jumper to select either 3.3V or 5V for powersupply of  (makes sense for a few situations)

c) a reset switch (on=reset) (my VESC never died to need a reset, but helps a lot when debugging)

 

Cheers

Sam

 

P.S.: Such questions are better put into the VESC original hardware part of the forum

Pedelec usage in combination with a GoldenMotor MagicPie3 BLDC

frank
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11.1V is the minium for the V6. I changed that on the website.