Remember if the LED was on or off after a reboot.

Press the boot button to toggle the LED.

Write "on", "off", or "toggle", then new line through USB to control the LED. You will get updates on if the LED is on or off.

Connect to BLE to read, write, and subscribe to notifications of the LED state.

• https://github.com/espressif/esp-idf/blob/5524b692ee5d04d7a1000eb0c41640746fc67f3c/examples/storage/nvs_rw_value/main/nvs_value_example_main.c
• https://github.com/esp-rs/esp-idf-svc/blob/master/examples/nvs_get_set_c_style.rs
• https://github.com/taks/esp32-nimble