openinverter forum

Hello everyone,

Im new here. I have some experience with programming, Arduino, python, html.
Bought 2 pieces of Damian Maguire tesla model 3 BMB control boards.
Watch all videos, see all schematics, read all topics, but cant get it work.
Soldered 4 batman chips, 2 myself, 2 by a pro, no result at all.

Setup: I only connect 12v power, GND, isoSPI+, isoSPI-
I should see values. I select M3 board, 1 module, and I tried also 4 modules.

When disconnecting SPI lines from connected tesla BMB I see 2 chiptemperatures.
Chipt0 = 87,5
Chipt1 = 5518.87

When connecting SPI lines,
Chipt0 = 87,5
Chipt1 = 10,68

So I think there is some data??
Both boards are doing it this way.

CPU load stm between 0-1.5%
Loopcount is updating, and refreshing.

So in my opinion:

Batman chip damaged? I heat it up to desolder it with flux at 250 degrees...
Dont know if this is okay? If not, any suggestions? Do someone know to buy complete boards, who are working?
Or anyone willing to do it, I have enough batman chips...

Thanks in advance,

Hans Kraaijeveld

So you have the V2 board with the added function of Maxim bms slaves. First thing to do is check you have your wiring correct as per the attached for the M3 slaves. I've gone ahead and added schematics and board layout for the V2 board to the Github repo :
https://github.com/damienmaguire/Tesla- ... M32_M3_Bms

Before connecting to a battery module at all , connect a scope to J2 and verify you are getting isospi out of the board.

Also please post a few photos of your setup so we can help with diagnosis.

Hello Jack,

I think I have not the v2 boards. I have these:

https://evbmw.com/index.php/evbmw-websh ... odel-3-bms
I connect M1 L1 H1 G1. I followed SPI+ and SPI- and they are connected on same way as on the test board on video from Damian.

My friend has a scope, tomorrow Ill make some pictures.

Without connected to BMB, only scope connected to Damian Maguire M3 control board

Can you please post a picture of your BMB and wiring?

Please post your params and spot values.

I'm guessing you have tried swapping the polarity of the isospi lines?

Is it possible to get a straight on picture of the BMB, specially focusing on the BMS chips. As this board looks different then the ones I have used and seen used with the BMS.

Jack Bauer wrote: ↑Sun Oct 05, 2025 5:13 pm I'm guessing you have tried swapping the polarity of the isospi lines?

Yes I have tried swapping SPI lines, because I didnt find in readme/wiring diagram what iso spi+ or iso spi- was. Only board, but not on Tesla BMB module...

tom91 wrote: ↑Sun Oct 05, 2025 5:27 pm Is it possible to get a straight on picture of the BMB, specially focusing on the BMS chips. As this board looks different then the ones I have used and seen used with the BMS.

Its laying upside down in a rack, so diffecult to take a good picture from above, but its exactly the same as I always see:

A next test point is the SPI data being sent and received via the Batman chip.

J4 has all the SPI chips broken out. Please attach a logic analyser to this and capture the traffic so we can analyse it.

There always is the possibility of the wiring being loose between the BMB and BMS, the purple connectors are super weak and very prone to destroying the traces on the pcb.

Hello,

What is good?

I have pinout batman ods: I have checked this by my damian board:
So what is wrong? Batman pinout ods or my board?

No I need a logic trace capture of the SPI comms to verify data is flowing as it should.

The trace will show:
1. Data from STM32 to Batman soldered on the board is working
2. Data from Batman to STM32 is working
3. Data from BMB to Batman to STM32 is working

I dont think I have a logic analyzer, and how to catch up.

But why is CS and EN not the same as it is in batman.ods?

Logic capture software: https://www.saleae.com/pages/downloads it is free

Logic analyser I use : https://www.amazon.co.uk/dp/B08JV4W1CD

I have this logic analyzer in stock

I think: connect GND (power also needed?) and miso channel 1 mosi channel 2?

Please grab a capture of a minute or 2 long and save it in the logic2 format and share it with us.

Its original a *.sal file, but I could not upload it, so zipped it

ShouldnI make 2 traces from both boards?