Acquire nRF905 + ESP32 hardware for a native receiver (Path C1)

[andy778]

Why

The cleanest path to Home Assistant is not SDR — it's a second nRF905 radio configured with the same parameters the unit uses, letting the chip do GFSK demod + address match + CRC for us. An ESP32 then publishes to HA (ESPHome/MQTT). This needs the radio config we're extracting from firmware on stream/radio.

What to do (can order parts now — lead time)

• Buy an nRF905 868 MHz breakout module (NOT nRF24L01 — wrong band) and an ESP32 (e.g. ESP32-S3) dev board.
• Wire nRF905 SPI (SCK/MOSI/MISO/CSN) + control pins (TX_EN, TRX_CE, PWR_UP, CD/DR/AM) to the ESP32.

Then (after stream/radio yields the nRF905 CONFIG)

• Program the ESP32 to set the same RF channel, address width, RX address, payload width, and CRC mode, put the radio in RX (ShockBurst) mode, and dump received payloads over serial.
• Compare against rtl_433/SDR results as a cross-check.

Deliverable

• Confirmation parts are on hand; a minimal RX sketch printing raw payloads.

Related: stream/radio (config source), #52 (cross-check), #53 (field mapping).