don't wire ADC to 5v

You need to use adc,. And hopefully your hall sensor chip can take a 3.3 volt input, cause adc maxes out reading above 3.3

I can walk you thought it when you’re ready

Up to you if you want a break regen switch
4153412281

1 Like

apparently it doesn’t “max out” but permanently damage the VESC if you have more than 5V on ADC

just FYI

5 Likes

I had more then that for a minute or two.

It didn’t die

2 Likes

@NuRxG get ur fax srt8

Sorry buddy, but if you’re attempting to call me out for telling people not to supply 5v to an stm32f4, its not gonna end well for you.

Here is the data sheet https://www.st.com/resource/en/datasheet/dm00037051.pdf

See page 15 for the voltage limitation (3.6v), and page 78 for the ABSOLUT MAXIMUM above which your chip will fry(4.0v).

Its cool that he had 5v for a minute or two and his didn’t break, I’m really happy for him. But I never have, and never will tell anyone to wire 5v to ADC, because IT WILL BREAK YOUR VESC.

6 Likes

fex extremely str8 now thx

3 Likes

my adc is wired to 5v 🤷

4 Likes

Mitch’s EUC comes screeching to a halt outside your apartment

Before you know it all your VESCs have had the STM chips desoldered and blended to dust

and IMUs added

2 Likes

Since there is almost no load, and whatever you’re wiring to it is probably some sort of resistor, I believe it will drop the voltage somewhat. I would still recommend switching it to 3.3v, but its not the same as shorting it to 5v. If your are shorting it to 5v, maybe you’re lucky it wont die, still not worth the risk, and not something you’ll ever hear me recommend.

4 Likes

Doesn’t this mean it is 5v tolerant?

4 Likes

we’re talking about throttle, no?

1 Like

Nope. Just specific pins are 5v-tolerant. Which ones depends on the specific stm32

No one promised that exactly this adc pin used for adc input on the vesc is tolerant

3 Likes

@longhairedboy can you merge all this into
“DON’T WIRE ADC TO 5V”

I want more than spintend customers and Mitch looking at this.

Thankz

2 Likes

Interesting find, I didn’t realize any of the pins are 5v tolerant (i don’t know the cpu that well). But i did a few minutes of reading and according to the datasheet page 59 section 5, even the 5v tolerant pins are only 5v tolerant when they’re not in analog mode, and ADC is analog mode.

4 Likes

the discussion was about throttle, not footpads which I think is what you’re talking about

ADC pins on HW6


I/O Structure for those pins

I/O Structure definition, TTa is not 5v tolerant

3 Likes

Properly designed hardware would have a resistor diode clamp to 3.3V so that at least the MCU doesn’t become damaged.

Or already made precompatible by buffering the signal with an op-amp and using a 1:2 resistor divider.

6 Likes

Are you saying throttles(not footpads) should not be wired to 5V?

In the schematic it looks like the ADC pins are wired directly to the output. I don’t really know much about circuits tho. Am i missing it in the official schematic? Is it guaranteed to have have those components on every vesc?

3 Likes

If the “official” schematic doesn’t have it, then chances are anything based off of it doesn’t have it. While the designers themselves know better, most will choose not to mess with “what already works”.

3 Likes