waiting for download (boot:0x3 DOWNLOAD_BOOT)
What it looks like
rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2)) waiting for download
What it means
The chip started in download mode and is waiting for new firmware instead of running the one it has. It does this when GPIO 0 (GPIO 9 on the C3, GPIO 0 on the S3) is low at reset.
Likely causes
- The BOOT button was held, or is stuck.
- A part wired to GPIO 0 (or GPIO 9 on the C3) pulls it low at reset.
- The board was left in download mode after a manual upload.
How to fix it
- Press EN or RST once, without holding BOOT.
- Move parts off the boot strapping pin, or make sure they cannot pull it low during 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
- Flashed fine, then nothing runs: GPIO 0 was low at reset, so the chip is waiting for firmware instead of running it. A part on GPIO 0 or a stuck BOOT button does this.