rst:0xc (SW_CPU_RESET)
What it looks like
ets Jun 8 2016 00:22:57 rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
What it means
The firmware restarted the chip itself. That is either a deliberate ESP.restart() or the panic handler restarting after a crash. If you did not call ESP.restart(), scroll up: the crash message is just above this line.
Likely causes
- A Guru Meditation error, abort or assert, followed by the automatic restart.
- A brownout on boards that report it as a software reset.
- Code or a library calling ESP.restart(), for example after a failed Wi-Fi connection.
How to fix it
- Read the lines above the reset; that is where the reason is.
- Call esp_reset_reason() in setup() and print it to log the cause of the last reset.
Paste your full log
The lines around the error usually say more. Paste everything from the reset to the backtrace and the crash translator explains each part. It runs in your browser; nothing is sent anywhere.
From the hall of flames
- Dies the moment Wi-Fi starts: The radio pulls a burst of current at start-up and the 3.3 V rail dips. Long thin USB cables and unpowered hubs are the usual reason.