Just a heads up, many boards (including ESP32 WROOM, at least from the schematics available) do not have a pull-up on flash /CS line. This means that when the ESP32 goes to sleep and GPIO is turned off, the /CS line is floating. This prevents the flash from going to standby mode. For my custom boar...

Does ch340g driver actually support these high baud rates? I never got ch340g working higher than 230400...

For the V3 WROVER-KIT, you don't need to connect any jumpers to get SD card working. We'll update the docs, thanks for the reminder.

Disabling interrupts for a long time (seconds), having tasks which run at high priority, suspending the scheduler — all these can cause similar errors.

You can pass extra arguments to Wire.begin:

https://github.com/espressif/arduino-es ... Wire.h#L55
https://github.com/espressif/arduino-es ... pp#L49-L63

esptool.py v2.0-beta1

That seems to be a fairly dated version of esptool (and hence the IDF). Support for D2WD was added to IDF in commit 6630877 (around first week of April). If your version of IDF is older than that, you will need to update it (including git submodule update to update esptool).

According to the spec (table 3-7 in ver 4.1) HS is mandatory for UHS50 and UHS104... So the issue is that TRAN_SPEED doesn't read 0x5a for some reason. I don't know why this is happening, but will order a few UHS cards to test. For HS mode we will also likely need to do delay tuning, especially for ...

const data is stored in flash by default.

Since IO0 and IO2 are also driven by RTS/DTR, maybe that's somehow part of the problem... Which OS and which terminal program do you use to connect to the board? Is there any difference in behaviour between connecting the board to a computer or to a USB charger?

Like this:
https://github.com/espressif/esp-idf/bl ... icon_bug.c