Balance side (uart_ota.c): downloads io-firmware.bin from Gitea to RAM,
computes SHA256, then streams to IO over UART1 (GPIO17/18, 460800 baud)
as OTA_BEGIN/OTA_DATA/OTA_END frames with CRC8 + per-chunk ACK/retry (×3).
IO side (uart_ota_recv.c): receives frames, writes to inactive OTA partition
via esp_ota_write, verifies SHA256 on OTA_END, sets boot partition, reboots.
IO board main.c + CMakeLists.txt scaffold included.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
sl-firmware
7ef6220e15