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>
Add dual OTA partitions (ota_0/ota_1 × 1.75 MB each) and otadata to
both esp32s3/balance/ and esp32s3/io/ on 4 MB flash layouts.
Enable CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE and OTA HTTP on Balance.
Create esp32s3/io/ project scaffold with config.h pin assignments.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
