rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)

[Vinayak]

Hi ESP Community.
I have connected 2 ESP modules by using SDIO. When I reset the HOST I am getting the following error message.

rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
flash read err, 1000
ets_main.c 371
ets Jun 8 2016 00:22:57

[ESP_Dazz]

Probably means that something when wrong when during the first stage bootloader. My guess is that your SD pins (or pull ups/downs) are conflicting with the SPI flash pins (they share the same GPIOs after all), thus why SPI flash boot has an error.