[Roberto-Gomes]

What

• New Heltec_v2_sensor env, building examples/simple_sensor for the Heltec WiFi LoRa 32 V2.
• The base Heltec_lora32_v2 section now pulls ${sensor_base} flags/lib_deps and
  helpers/sensors, and target.h/.cpp use EnvironmentSensorManager instead of
  SensorManager, the same way heltec_v3 does.
• ENV_INCLUDE_GPS=0: the V2 has no GPS, so no MicroNMEALocationProvider is built
  (same override as minewsemi_me25ls01 and wio_wm1110).

Why

The V2 had no sensor env, and its SensorManager only reports battery. With
EnvironmentSensorManager, I2C sensors on the OLED bus (SDA=4, SCL=15) are
auto-detected, e.g. an AHT25 at 0x38 next to the OLED at 0x3C.

Testing

• All Heltec V2 envs build (PlatformIO). Size before (dev 428a95c) and after this change, in bytes:

  env	RAM before	RAM after	Flash before	Flash after	Flash Δ
  Heltec_v2_repeater	60520	62336	1151941	1203525	+51584 (+4.5%)
  Heltec_v2_repeater_bridge_espnow	62192	64016	1162745	1214241	+51496 (+4.4%)
  Heltec_v2_room_server	64208	66024	1147337	1198901	+51564 (+4.5%)
  Heltec_v2_terminal_chat	61116	62940	530577	587597	+57020 (+10.7%)
  Heltec_v2_companion_radio_usb	66628	68436	608381	660129	+51748 (+8.5%)
  Heltec_v2_companion_radio_ble	104112	105920	1426281	1478769	+52488 (+3.7%)
  Heltec_v2_companion_radio_wifi	109928	111752	1079381	1131293	+51912 (+4.8%)
  Heltec_v2_kiss_modem	25552	27372	505321	566501	+61180 (+12.1%)
  Heltec_v2_sensor (new)	–	60384	–	1209789	–

  The cost is about 52 KB of flash and 1.8 KB of RAM per env, from the sensor_base drivers.
  The largest env (companion_radio_ble) uses 44.2% of the 3342336-byte app partition.

• Hardware test with four Heltec V2 boards, all on the same build: a Heltec_v2_companion_radio_usb
  driven by meshcore-cli, a Heltec_v2_repeater, and two Heltec_v2_sensor, each with an AHT25
  on SDA=4/SCL=15.

  • With -D MESH_DEBUG=1, both sensors log Found AHT10/AHT20 at address: 38 at boot
    (AHT25 picked up by the existing Adafruit_AHTX0 driver, no code change).

  • With the normal build, the companion received the sensors' adverts, and after login,
    req_telemetry returned the AHT25 readings on channel 2 next to the battery voltage on channel 1:

    SensorA: voltage 3.95 V (ch1), temperature 28.6 °C (ch2), humidity 76.5 % (ch2)
    SensorB: voltage 3.95 V (ch1), temperature 29.2 °C (ch2), humidity 74.0 % (ch2)
    

I used Claude Code to help with this change. I reviewed the diff and ran the tests above on my own boards.

[cronyx]

Hello! You can set -D PIN_GPS_RX=12 -D PIN_GPS_TX=13 for use external GPS module and the build will complete successfully