Develop a QCA7000 board?

[uhi22]

Just remove all components which are connected to the TX lines of the QCA, and measurse both TX lines with oscilloscope.

[Gabriel]

The problem was the Flash memory, which recorded normally, but erased after some time. I don't know why yet. The memory is W25Q16.

Thanks for the tips.

[uhi22]

Do you know, whether in this case the software version of the modem was reported with "Bootloader" on the serial console?

[johu]

So it seems like I have (at least partially) killed my Foccci with over voltage.
I recently added the changeover relay between stationary battery and EVSE connected one.
I am currently travelling and the relay was connected to the stationary battery. That means the small HV source hasn't got anything to work against that stops the voltage from going sky high. I wouldn't be surprised if it reaches multiple kV with the way I have it set up right now.

My wife decided to plug in the car because it was quite sunny. I saw the state machine reach Precharge and then it dropped back to off. After that I could not get any communication going anymore. plctools still find the EVSE modem so that seems fine.

My wife then drove to the shop and reported the EPC signal was blinking. That is very unusual as the EPC light reacts to the P-FET that is switched on when PP goes low.

So not 100% sure what is damaged and why. Maybe the high voltage somehow made it over to the PFET and killed it on some weird way that it now blinks? Or it traveled through the temperature sensors that have good thermal connection to the HV pins.

This is an old revision Foccci with no protection on PP. So this might not have any implications for current revisions. Quite sure I need to swap the board though