V2.2.1 - FeatherS3-D bring-up prep

Summary

FeatherS3-D bring-up preparation. Two behavioural changes affect FeatherS3-D only; Heltec WiFi Kit 32 V2 build is byte-for-byte equivalent to V2.2.0.

Changes

Pin remap to Feather A0..A5 (FeatherS3-D)

The FeatherS3-D pin map now uses Feather A0..A5 (left-edge) hole positions instead of arbitrary GPIO-numbered right-edge positions. This makes the wiring harness portable across Feather-form-factor boards: the same harness drops onto e.g. Adafruit ESP32-S3 Feather #5323 by changing only the GPIO numbers in hal.h (no PCB rewiring).

Signal	Feather position	FeatherS3-D GPIO
HV_CAP_FUL	A0	17
GMC_COUNT	A1	18
HV_FET_OUT	A2	14
SPEAKER_P	A3	12
SPEAKER_N	A4	6
HWTESTPIN	A5	5 (reserved)

External-antenna toggle (FeatherS3-D u.FL)

New "Use External Antenna Port" checkbox in the WiFi section of /config. Default OFF (onboard PCB antenna). When ticked, drives IO41 HIGH to route the WiFi front-end to the u.FL external connector via the onboard SPDT RF switch. The checkbox is greyed out and disabled on Heltec, which has no antenna switch.

Boot log shows the active routing:

• antenna routing: internal PCB (gpio 41 = 0)
• antenna routing: EXTERNAL u.FL (gpio 41 = 1)

Heltec V2

No behavioural change. Both code paths above are gated by HAL_HAS_ANTENNA_SWITCH / per-board pin macros.

Artefacts (10 files)

Five files per board, board-suffixed. For OTA upload (existing devices), grab geiger_v2_<board>.bin. For first-flash on a fresh module, use geiger_v2_merged_<board>.bin at offset 0x0.