unstable Wi-Fi connection

[medo]

Does anyone know why I can't get a stable wifi connection? Sometimes I see data, sometimes I get the error message "Communication problem between ESP and STM"
I have already tested both modules, Olimex and Wemos D1, both have the same reaction

[johu]

It means the UART communication between ESP and STM32 has issues. E.g. bad connection, out of sync baud rate etc.

The latter can be improved by running the latest firmware that you find on github. I'm assuming ESP8266 https://github.com/jsphuebner/esp8266-web-interface

[medo]

The current firmware is already installed, so far nothing has helped, maybe a hardware error??

[uhi22]

I may be wrong, but my understanding was that this error message may be misleading. Because it not only pops up if there is a communication issue between the wifi module and the STM32, but also if there is a communication issue between the laptop and the wifi module. If this is true, I could imagine the following root causes:
- Wifi connection bad (due to shielding or/and distance)
- ESP resets due to bad power supply

To narrow-down such issues, I'm dreaming of some more debug information which could be observed in the web interface, like up-time, communication counters for RX and TX on serial line and CAN, number of TCP packets received and transmitted, ...

[medo]

I would prefer a wired environment with the appropriate software, wifi would always be second priority because it is susceptible to interference, that's how I did it in the smart home, everything wired, only where there is no possibility

I swapped the modules around and it is always the VCU that sporadically establishes a connection

[uhi22]

Yes, also my strategy regarding reliability is: "a wire is a wire". And second strategy regarding reliability: "Do not use the crappy ESP controllers."
But on the other hand, the Wifi stability has drastically improved over the last 20 years, and there are applications with the ESP which are running over years just stable.

What are the conditions/actions to loose the connection, and to heal the situation?
- Just randomly it disconnects and heals?
- Needs a reload of the web-page to heal?
- Needs a power-on reset to heal?
Any chance to observe the serial lines with an oscilloscope or logic analyzer or serial sniffer?
Maybe power supply issues of the ESP, or of the complete module. Any chance to change the power supply, or to inject a reliable 5V or 3.3V from a bench power supply?

[Zieg]

Aren't those olimex boards a bit flaky anyway? Mine does the same thing from time to time. I put a Wemos D1 Mini in my Tesla charger and noticed it seemed to perform a lot better.

[medo]

After I switched to the older version of the web interface firmware, everything works as before, the olimex is really rubbish, I have now switched to Wemos, I think the web interface 2.0 is not yet fully developed, at least on the vcu, even with the Wemos I keep having connection problems, my favorite remains a USB connection, which unfortunately does not exist

[medo]

Now I have switched everything to wemos with the latest firmware and logged into the home network, everything works fine, except for a few short connection losses

on the VCU

on the LDU

everything is OK, except for the error message cancounter, unfortunately I don't know what the reason is at the moment

I also inserted the can id's from 400-430 in the inverter as described, but nothing comes through on the VCU