60v* ESP32-C3 and PwrTool 500

[minor cipher]

Hi friends! Late last year, I released my FLIP_C3 dev board which is designed to work on 12-48v battery systems via a built in 5v/2a buck converter. It seems pretty popular despite the slight issue in the first round if you're using above 50v (check the docs). Working on fixing this in the next version coming in about a month. Anyways, I designed it to be used in a few upcoming projects, one of which in pre-launch on Crowd Supply. I decided to design my own 500a smart shunt for battery monitoring and I call it the PwrTool 500. I'd love whatever feedback you have.

https://wiki.vdbx.io

[tawdry trail]

I might be blind, but can't find where you're selling those.

And are you plannig a version with less Amps ? I plan to monitor my fridges power usage

[tender ravine]

well if its a DC fridge for RV or marine usage, then it'd work fine as is, just at lower resolution. But of course its DC only and not suitable for home fridges as a result

(as for me, I am interested in one of these for some DC applications, especially once the 60V inrush issue is fixed)

[tawdry trail]

Marine usage yes, 12V DC fridges

[minor cipher]

I have the FLIP_C3 available on https://www.vdbx.io and amazon, but the PwrTool isn't released yet as I'm going to be doing a Crowd Supply campaign for funding production. I do plan on doing smaller and larger versions in the future, but have not yet gotten to prototyping them yet.

[minor cipher]

Testing next version right now and results are promising. Current version can be connected to a battery when it's below 50 and still be in spec at 58+ when it's charged. As long as you don't have any switching on its power input.

Also these are really good for just grabbing a random power supply from your hoard or say you're working with 12-48v stepper motors

[tawdry trail]

@minor cipher Please ping me when the crowsupply starts. If I can afford it at the time I'll buy some. It's very addictive to have home automation on the boat you live full time in.

[minor cipher]

Totally! You can also put your email in on the CS page. I designed all this for the bus I’ve been living in for the last 4 + years, so I know what you mean. 😊

[tawdry trail]

Living on the boat for last 4 years, but in countries where I have no address so makes it hard to order things 😛

[tender ravine]

Yeah that's the problem. Where the module is likely to be mounted, it will have switched power and often at full charge of a 13S lipo

Still, I know you're working on it, I'll probably grab a few when available

[tawdry trail]

I dont have the problem I'm all 12V 🙂

[sick estuary]

what is the resolution of the voltage and current measurements?

the new revision that's currently being brought to market, it will have the inrush issue fixed and be compatible with 16s LiFePO4?

[sick estuary]

making some assumptions looks like the resolution is about 0.01 amp just based on the max amperage and adc resolution, any possibility of different shunt sizes for different ranges / increased resolution for lower power circuits?

[sick estuary]

in fact I could probably use a 1000 amp, 500 amp, and a couple 100 amp, any update on manufacturing @minor cipher ?

[minor cipher]

the resolution is 16bit from the ADC, but normal home assistant use doesn't need all that, so it's not default, but can be changed in the ESPHome config.

[minor cipher]

The FLIP_C3 v1.1 with proper TVS protection is being produced as we speak

[minor cipher]

I do plan on various shunt versions and a DIY bare board version, but I'm focusing on getting thru funding from the crowd supply on the base model so I can not have to live in my bus anymore. I don't wanna push myself with that many SKUs rn

[sick estuary]

that's fair enough, do you think the shunts will follow soon after the flip revision or will it be a bit longer? just wanna say I love this product, it really fits a gap in the market and is well designed with some thoughtful features

[minor cipher]

the shunts probably wont be shipping until spring

I'm thinking CS finishes around new year then production

[minor cipher]

thank you so much.... I'm doing bay area maker faire in about 4 weeks if you're local

[sick estuary]

seattle at the moment unfortunately... I'm subbed to the email list though, and look forward to any updates, this is exactly the product I was looking for!

[reef pilot]

@minor cipher hi, what is the power consumption of the buck converter if the esp is in deepsleep?

[minor cipher]

I don't have any testing done in deep sleep, but from the datasheet, if the load is under 400mA (which the C3 itself shoudn't get above on it's own) the buck converter will have a quiescent current of 40 uA https://www.ti.com/lit/ds/symlink/lmr16020.pdf

BTW y'all, I have v1.1 in-house and I'll be processing them soon.

[reef pilot]

awesome. what changed in 1.1?

[reef pilot]

So your are using that chip to go from <60V to 5v and the linear regulator to go to 3.3v?

I guess the linear regulator is similar efficient?

[minor cipher]

Ah, yeah. I can check that in a bit. I can’t remember off the top of my head, but it’s probs decent.

I’ll write some stuff up for that too so it’s not stuck in the schematic/BOM.

[reef pilot]

thanks. I would want to use it with two lithium cells to gather sensor data every few seconds, so power consumption would be crucial.

[minor cipher]

Honestly, you’re better off with a standard dev board with a charging circuit, unless you have a specific reason to put them in series and have your own charging circuitry.

[tender ravine]

"every few seconds" "battery" "wifi" are not something that typically goes together well

It wont be the LDO thats the problem there either, though an LDO going 5v to 3.3V is gonna be 66% efficient at best

[reef pilot]

No wfi needed

[minor cipher]

sorry for the delay - quiescent current is ~100uA on the LDO

[cedar kindle]

@minor cipher thanks for making these 🙂 I just got my first one (ordered from Amazon) as a test unit. Such a relief to have a 12/24V powered ESP32 on a bus 🙂 No more mucking about with separate unreliable buck converters for simple projects

[minor cipher]

Yeah, I was so tired of fiddly trim pots or limited input voltage.

Best compliment, thank you! Lmk what you come up with.

V1.1 is up on Amazon now if I hadn’t already mentioned it.

[cedar kindle]

Probably going to use them everywhere now :). I have a Victron smart shunt I want to monitor via … is it VE Direct? (I saw you will be releasing some shunts soon… that will be cool!). I’ve got a tank monitor that has an RV-C interface… will use another one there since I have no other RV-C on the bus. I’ll use them all over the place for lighting. Probably another to replace my AC powered zwave relay box that I use to control my diesel heater (which is, itself, 12V powered).

[minor cipher]

i'm reading the Ve direct from a smart shunt via one of my PwrTool 500s to test against it. It should be live on Crowd Supply in Jan/feb

[cedar kindle]

@minor cipher with WLED, can I mix LED types? I.e. can I use L8 with a WS2814 strip? Or... because the onboard LED is WS2812 that will mess with things? (I've got my WS2814 strip hooked up using L8 as the output... and while it controls the strip, the colors are all wrong. I choose green and the LED on the Flip is green... and the strip is red.). Wondering if I should just move it to a different GPIO. Also... I copied my WLED config from a different ESP32 dev board where I wasn't using the onboard LED as a level shifter... so... I'm a little lost 🙂

[minor cipher]

I haven't done extensive testing on this, but I would probably suggest just switching to another GPIO unless you can get it to behave with one of the other protocols in the list. I would assume this would end up making the onboard LED the wrong color if it does work.

usually you should have a level shifter for 5v data, but with the LEDs I've used, they're usually fine on 3.3 logic if the first pixel is close to the board

[cedar kindle]

Hmm. This has me stumped. I can’t seem to get it to control my light strip from another GPIO.

[cedar kindle]

That is what I assumed should happen. But… it doesn’t seem to work that way.

Hmph. Well. Sleep for now. Will look again another day. I’m sure I’m missing something.

[minor cipher]

it's not working on a different GPIO?

[cedar kindle]

Nope 😦 Though... the whole WLED interface is acting a little weird, and it seems to be dropping off my network periodically. I'm gonna try reflashing it... or maybe swap to a different device and see if it behaves any better.

[sick estuary]

@minor cipher when I asked previously, you said that the shunts wouldn't ship till spring - no worries, and I know I'm a bit early in asking this, but it's been a few months and your design really does perfectly fit my use case - so I'm just wondering if you can give an update on expected timeline? thanks! really looking forward to being able to purchase these (and, bug in your ear for long-term, 50, 100, 500, 1000 amp options would be really nice!)

[arctic linden]

1000 amp!?

[minor cipher]

I'm currently in the process of moving from the bay area to the socal desert and I'm gonna be boondocking in my bus on public land until I find a place. I'm gonna be real and say the actually shipping date is gonna be fall. I do have beta units (which are basically final hardware) available to anyone who can provide feedback, and preferably post about it.

[sick estuary]

@minor cipher I'm a software engineer with hobby level hardware design background and have made some contributions to esphome itself, I can certainly test them and provide feedback but I don't have a large social presence

[sick estuary]

at 12v 500 amp is only 6000 watts 😉

[minor cipher]

that's all i ask honestly - there's a link to my discord at https://wiki.vdbx.io