openinverter forum

Hi, I have been starting up a Tesla SDU with a can-based wifi module.
Should have been simple enough but I have not been able to get the connection working between the STM and the ESP32. I measured all voltages and my best guess is the can transciever is shot. It measures 1.27 volts, CANL to ground when running but not connected.
I checked some trouble searching and this seems one indication of hardware fault.

Are there any other possible issues that could make the CAN interface not connect such as the software version on the openinverter card or should this be all clear?
In that case I guess my best bet is a new ESP32 card.

Thanks, Kristian

You need to run a recent version of the inverter firmware, like 5.27 or higher

Apart from that it's just baud rate and physical connection

Thanks for the fast reply, great work you’re doing here!

Problem is i only have the CAN card so it’s not easy to validate the baud rate nor check the sw version.
How do I go about this, can I run some commands using the uart directly with a rs232 interface?
Anty reference for the commands?
I tried to check around for this also but didn’t find much.
On the tesla sdu, pins 14 and 16 should be the uart of the stm so I can connect easily there.

Thanks again

There is no UART on the SDU pins, that is left over from very old boards.
Did you buy the pair (ESP and SDU card) from the shop?

If you manage to hook up a uart directly to the SDU board you can start at 115200k and send the command "json\n"

Ok, thanks. I hopked up directly to the pins on the breakpit to the sdu board. It works so I should be able to get the sw installed this way woth abuart interface. Unfortunately i did not solder pins here and now the board is installed with the current sensors…
I am out of town for a few days, will load newer sw when back again.
I can use the uploaded.py with the sine hex?
Thanks

Yes just stick some jumper cables in there and hold them under tension.

uart-updater.py is what you want to use https://github.com/jsphuebner/stm32-CANBootloader/

Great, will try when I get back. For the Tesla SDU, the stm32-sine.hex is the build to use, right?

stm32_sine.bin it is for the py script

Yes, thanks!!

OK, back and checking. It finally works. But with a twist... the whole time I set up the can nterface to connect to my wifi, following I was using inverter.local to connect and since my computer (Windows) doesn't pick it up, I was using my phone (iphone) with safari...
The phone doesn't work... however my computer does. So this is probably more of an ESP32 problem than with my connection.

So for anyone having trouble, the phone may have issues. You can pick up the ip there though and follow up with the computer.

Thanks, for the support and let me know if there is anything else you want to me to check to sort out the bug.
I did some ESP8266 programming previously and the simpler versions of web interface does not support multiple connections, this doesn't seem to be the issue here but maybe there is some other flavour of the builtin ESP32 libraries that have issues with the phone.