Q: How to implement reliable firmware updates over UART on STM32?
Answer
UART bootloader is built into STM32 System Memory. Enable it by setting BOOT0 pin high or configuring option bytes. The host uses STM32 Cube Programmer or custom protocol via YMODEM or raw binary. For custom OTA: divide firmware into packets with CRC16/32 integrity check version number and sequence number. Implement a dual-bank update: write to inactive flash bank verify CRC then swap boot selection. On STM32 with dual-bank flash enable boot selection via option bytes. Always reset the watchdog timer during the update process. The bootloader receives at 115200-460800 baud depending on clock speed.
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