Flash an expander ESP via serial?

[falkoschindler]

Currently we flash port expanders using a serial connection and G0/Enable pins. But to save pins and to simplify wiring of external port expanders, we think about flashing the external ESP with a serial connection alone. The idea is to use a similar protocol like OTA updates, but sending the binary over wire.

[falkoschindler]

I'll close this discussion in favor of #34.