openinverter forum

Hey all,

Currently combining all my parts to test a first motor spin. Previously I tested communication between the Zombie and my Outlander motor, inverter and charger, this all went well for as far as i could test them. After that I calibrated a throttle pedal which i picked up. When testing the motor, inverter and charger I also tested the BMW S-BOX to see if the contactors worked like they should, by setting UDCSW to 0 volt the contactors happily clicked away at the moment they needed to.

Recently I did a Zombie update to 2.20. Now I'm at the point where I want test the motor, but before that, I wanted to make sure that all component were connected and functioning well, so I fired up de Zombie webpage and saw that UDCSW had a value of -20 (negative). I have tired to change this value many times but it keeps reverting back to -20 after I hit refresh. Other parameters gave no problem changing them. I Have tried to change the UDCSW value with and without my components connected. I tried flashing the 2.20 software again this didn't result in what I hoped for.

Even when the UDCSW value is at -20 the Zombie goes into RUN mode when pushing the start button, but at that point I hear no clicking of the contactors (double checked the wiring).
Any one has an idea how to be able to change the value?

Many thanks!
Sander

In the Zombie SBOX code, UDCSW is set to the (Battery Voltage - 20) Volts, So no need to set it via the params.
From the GIT history, seems to have been added going into v2.20

https://github.com/damienmaguire/Stm32- ... a44317R300

Yes the UDCsw is now based on your reported battery voltage -20V. Next step would be to have hv or any voltage/number of modules (over 20V) into the Sbox check you UDC values populate and your udcsw updates accordingly.

Hi Tom and Mitchy,

Ok, great! Thanks for your ultra fast response

I'll connect some power to the S-BOX and proceed testing. I'll report my findings here.

Cheers

Hey,

I've tested everything again, after connecting the S-BOX to CAN 1 instead of CAN 2 and connecting a 30V power supply, UDCSW did show a positive value. At that point it was possible to close the contactors, UDC and UDC2 both show comparable values.

So that all worked out nicely. I have to admit that this new way of setting the UDCSW voltage is a good safety addition!

Cheers and thanks again!
Sander

Sjanders wrote: ↑Sat Feb 22, 2025 1:13 pm new way of setting the UDCSW voltage is a good safety addition!

This only works with compatible Shunts. So its a more "clean" way of doing UDCsw makes it nice and dynamic