openinverter forum

Is there a way to get rid of the whole WIFI thing? In the time that I always wait until a shaky connection is established, I could have laid a cable from the motor to the PC 10 times!

If you manage to route UART TX/RX out of the enclosure and convert to USB at some point, then yes you can.
Mind you, you do start out with only the text console and can then run the web interface locally on your computer. The kind of stuff that needs lots of explanation that I wanted to get rid of
Also USB or UART is prone to EMI. Try it.

EDIT: in the same way you could connect the wifi module outside the enclosure.

From my experience, the issue is mostly the device having more than one (VCU) WiFi connection available and switching to the best signal. Solution: Forget all connections except the VCU

Also get a wifi scanner app for your phone and have a look at what channels are free around your house. A company setup near me last year offering "community wifi broadband" and it caused me HUGE problems with inverter wifi connects until I changed to a channel they don't use.

This solved all my wifi issues.
https://github.com/martin-ger/esp_wifi_repeater I have a NodeMCU with cheap buck converter in a plastic box about 12" from the inverter. I can connect from outside my garage.

I am also playing with some CAN bootloader examples Ive come across. Since all my devices are on a 500k bus, it would be interesting to wire in an OBDII port and be able to flash any node on the bus.

Here is a libopencm3 CAN bootloader example I found.
https://github.com/cvra/can-bootloader

I've been working the purely C stm32 HAL space so what Im playing with hasnt been directly applicable to the open inverter projects yet.

Yes I've been thinking about CAN firmware updates ever since I introduced CAN to the hardware. No one ever requested it so I couldn't be bothered

A SDO request could send the device to the boot loader and the firmware would be dumped onto 0x7ff ID. So with multiple devices you want to get your node ids right

A bit of handshaking would be good, like a start datagram specifying number of pages, a crc request and result. Thats about it, much like the UART variant.

I have wifi only in my main microcontroller, Teensy 4.0 with 4 CAN bus. Then I can control charger, inverter, BMS, heat/cool, instrument panel and more from one unit. This way I can have dedicated CAN bus for the inverter and BMS, and no trouble with different speed and CAN bus traffic.
Would be nice to have firmware update also from CAN, a update on USB stick plugged in to the Teensy?

viewtopic.php?f=16&t=433

johu wrote: ↑Wed Jun 30, 2021 8:57 pm Yes I've been thinking about CAN firmware updates ever since I introduced CAN to the hardware. No one ever requested it so I couldn't be bothered

A SDO request could send the device to the boot loader and the firmware would be dumped onto 0x7ff ID. So with multiple devices you want to get your node ids right

A bit of handshaking would be good, like a start datagram specifying number of pages, a crc request and result. Thats about it, much like the UART variant.

This is the way togo imho too.
If at all the car needs to have one wifi and from there we update over CAN all modules.
(atleast thats the way i see it).

Now doing it over the OBD2 port might be challengeing because many cars have a gateway coordinating that traffic.
If the main car MCU is pulled out there might be UDS adresses available of wich i suspect the gateway only forwards that traffic to it.
To check that we should unraffle the OBD2 spec to see what the gateway makes of those packages.

Another trick is to simple populate the BUS on 2 pins which are unused on the OBD2 port and make a special adapter or cable.

This aged well!