Yes, a TRM chapter for this peripheral is planned, however at the moment it is of a relatively low priority, so I can't give you any timeline.

The names "protocol" and "application" are somewhat of a legacy. In practice the only difference is that the CPU0 is responsible for application startup (up to the point when app_main runs). From that point on, FreeRTOS tasks can be created and run on CPU0, on CPU1, or scheduled automatically (on CP...

Please try disabling Wi-Fi modem sleep (which is enabled by default) using esp_wifi_ps_set function. Perhaps this will improve the situation?

No, the earliest you can register a GPIO ISR is when app_main starts. When deep sleep wake stub is running, FreeRTOS has not started yet, so interrupt servicing using the driver is not possible.

Thanks for checking, very interesting. Could you send me your application .elf and .bin files via a PM?
Also, is there anything special about the way you are building the application (new CMake build system, or something custom)?

In this case the path is going to be "0:foo.txt" (instead of "/sdcard/foo.txt"). See http://elm-chan.org/fsw/ff/doc/filename.html for the fatfs library format of file names. Normally when you use C library functions or POSIX functions which work with files, these functions translate full paths (such...

In this case, gdb server is provided by OpenOCD. If you are using xtensa GDB as the client (via MI), then it should be able to talk with OpenOCD. If you are running generic GDB (not cross GDB for Xtensa) then there certainly will be an issue. Can you trace somehow, which GDB binary is used by Micros...

Yes, f_utime should work, provided that you pass the correct path (e.g. 0:file.txt where 0 is volume number and file.txt is the file name inside FAT partition)

Sorry for the late reply. Could you try EXT0 or EXT1 wake up method for UART RX pin, and see if it can wake the chip up from light sleep when something is received? Another thing to try, connect the external serial device to UART0 instead of UART1, and see if wake up from UART0 works using your code.

Please see this example: https://github.com/espressif/esp-idf/bl ... /README.md