Brownout detector was triggered
What it looks like
Brownout detector was triggered ets Jun 8 2016 00:22:57 rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
What it means
The 3.3 V supply dipped below the safe level and the chip reset itself to avoid corrupting flash. It almost always happens when Wi-Fi or Bluetooth starts, because the radio draws bursts of several hundred milliamps.
Likely causes
- A long or thin USB cable, or an unpowered USB hub.
- A weak 3.3 V regulator on a cheap board, or a battery that is nearly flat.
- Motors, LED strips or servos powered from the same 3.3 V or 5 V pin.
How to fix it
- Use a short, good USB cable plugged straight into the computer or a powered hub.
- Put a 100 µF to 470 µF capacitor across 3V3 and GND, close to the board.
- Power motors and LED strips from their own supply, sharing only ground.
- Lower the Wi-Fi transmit power with WiFi.setTxPower(WIFI_POWER_8_5dBm) after WiFi.begin().
- Disabling the brownout detector hides the symptom and risks flash corruption; fix the power instead.
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.