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Second Life EV Batteries has Telsa P100D shunts cheap https://www.secondlife-evbatteries.com/ ... hunt-p100d @tom91 has some code for them https://github.com/Tom-evnut/Tesla-Current-Shunt

I've just had one delivered to play with.

Already forgot I wrote code for this item. .

Please note the Shunt is HV referenced, you NEED a digital isolator somewhere in your interface.

tom can you rember if the shunt needed 5v or 3.3v vcc when you used it?

Its is an arduino Uno Sketch so 5V was most likely used. You can first try 3.3V to see if it works.

I have created a simple SPI isolator in easyeda and was wondering if any EEng could give some advice ... I have placed the tracks as far apart as possible for isolation however i have not used a ground plane is that probably ok in this situation? also as the voltage is at most 400v it didn't seem necessary to make a machined air gap is rhat also ok? Any advice would be appreciated.
PS ic is ADUM1401CRWZ-RL & 3,3v to 5v DCDC is TBA 1-0311m also this will be released publicly once finished,

rstevens81 wrote: ↑Sat Apr 10, 2021 9:51 pm I have created a simple SPI isolator in easyeda and was wondering if any EEng could give some advice ... I have placed the tracks as far apart as possible for isolation however i have not used a ground plane is that probably ok in this situation? also as the voltage is at most 400v it didn't seem necessary to make a machined air gap is rhat also ok? Any advice would be appreciated.
PS ic is ADUM1401CRWZ-RL & 3,3v to 5v DCDC is TBA 1-0311m also this will be released publicly once finished,
Screenshot from 2021-04-10 22-42-06.png

Great idea!
I would use a DC/DC with greater physical leg distance between primary and secondary side, for example https://www.mouser.se/ProductDetail/CUI ... blDw%3D%3D
I also suggests use of 2pcs of bypass capacitors(ceramic) of 100nF connected between pin1 & pin2 resp. pin15 & pin16 on the adum isolator IC, located as close to the IC as possible.
I would avoid any routing making the isolation distance shorter than the component leg distance, ie no routing under the components over the isolation barrier. Also, might be good idea to have a ground plane on each side of the barrier, on the backside of the board.

I think i have captured your suggested changes any further suggestions or and mistakes i have made

Looks good to me.
There is no harm in extending the ground planes to fill the entire board, except for the isolation barrier, but will work as is.

published:
https://oshwlab.com/rstevens81/SPI-Isolator-Tesla-Shunt

Have ordered pcb (from JLC along with components from LCSC) will feed back any findings.

Note: DCDC changed to more readily available one.

Got one up and running with 3.3v.
Contains a IHM-A-1500 from ISABELLENHÜTTE https://studylib.net/doc/18803520/ihm-a-1500, a STM8AF6266TC and a 2903AVQ.

Based on datasheets 3.3 or 5v should be fine, based on my uneducated reading of them

I've used a DC clamp meter to take some measurements

https://docs.google.com/spreadsheets/d/ ... sp=sharing

It looks to be little endian, divide by 2 and then divide by 10 for amps.

Thanks for your work put into this design! The links are not working anymore. Does someone still have the schematic and board files? I would appreciate it very much, as I have a Tesla shunt lying around.

Please note the Shunt is HV referenced, you NEED a digital isolator somewhere in your interface.
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For clarification/understanding - the shunt monitors and calculates current and voltage measurements. The digital isolator that you speak of is another component.If so, what are you using with the the shunt for isolation monitoring?

This only provides a current that needs to be obtained by querying it over SPI.

The shunt is 5V powered and thus has a ground reference. Due to it being a resistive based (thus a shunt) its ground is tied to what ever it measures.

All info is on the github i posted. https://github.com/Tom-evnut/Tesla-Curr ... 0Shunt.pdf

This clearly is an advanced electronics/software project for someone with sufficient knowledge to tackle. If you cannot code and create electrical circuits DO NOT attempt this.

My advice is to get an ISA shunt, even at full price they are worth every penny... But if you wait around normally someone starts selling them cheap from time to time (keep eye on DIY electric also). I did a design with isolated dcdc and an spi isolator chip using a wemos D1 for can however I couldn't get the isolator chip to work right, and found a cheap shunt so abandoned the design.
It's not easy as you have to deal with isolation gaps etc. in my honest opinion given the time needed to make a safe design you could probably buy a few at full price!! And the ISA shunt is a well designed bit of kit used by the OEMs!!

Message me if you are looking for an ISA Shunt. I'm arranging a group buy to the UK.

Thank you for your honest opinions! I'll go for an Isabellenhütte shunt then (though I'm not based in the UK).