Add Heltec WiFi LoRa 32 V3 board documentation

docs/basics/compatible-controllers.md

@@ -128,6 +128,7 @@ ESP-01 | ESP8266 | One of the first and cheapest ESP8266 boards available. **_No
 ![Gold Member](../assets/images/content/akemi_gold.png)<br/> [ESP32 Mini Dev Board 16mb by SerKo (aka Serg)](https://www.tindie.com/products/28858/)| ESP32 | ESP32 Dev Board with latest WROOM-32E module, USB Type-C, PTC fused, over-voltage protection. D1 Mini32 form factor and compatible [pin out](https://github.com/srg74/WLED-wemos-shield/blob/master/resources/ESP32_mini/Resources/ESP32_mini_board_pinout.pdf)
 [H803 WiFi](https://github.com/srg74/WLED/wiki/H803WiFi) | ESP8266 | ESP8266EX based controller with level shifter inside. Data pin GPIO1 Clock pin GPIO14. Tested with WS2813 strip and [Firmware fork is here](https://github.com/srg74/WLED/tree/H803WF).
 [Heltec WiFi Kit 8](https://heltec.org/project/wifi-kit-8/) | ESP8266 | Another alternative of ESP8266 board. OLED display 128X32 pixel, battery charger on board. Almost the same functionality and price as the Wemos board. Plus it can be used in projects with external batteries.
+[Heltec WiFi LoRa 32 V3](https://heltec.org/project/wifi-lora-32-v3/) | ESP32-S3 | Compact board with ESP32-S3FN8, 8MB Flash, 320KB RAM (**NO PSRAM**), 0.96" SSD1306 OLED display, and LoRa 915MHz. **Must use `heltec_wifi_lora_32_v3` build environment.** Onboard I2C display (GPIO17 SDA, GPIO18 SCL, GPIO21 RST, GPIO36 Vext). Supports WiFi, Bluetooth, and display usermod. See compatible hardware section for OLED setup with FLD_PIN_RST and HELTEC_VEXT_PIN.
 [Lolin32 Lite](https://www.aliexpress.us/item/3256806000205489.html) | ESP32 | Low cost ESP32 board optimized for battery usage.  Does not have a 5v pin but can be powered with 5v on battery connector.
 [NodeMCU](https://github.com/nodemcu/nodemcu-devkit-v1.0) | ESP8266 | Another popular ESP8266 development board. A bit bigger than the D1 and has pins pre-soldered. There are multiple versions with slight differences, not all are tested.
 NodeMCU-32s | ESP32 | The most common ESP32 development board. Works well, depending on the board you might have to press the "Boot" button while USB flashing

docs/basics/compatible-hardware.md

@@ -72,6 +72,26 @@ How to connect Levelshifters:
 [CH340](https://www.aliexpress.com/item/32761423124.html) | CH340 module instead of CP2102, PL2303 or FTDI/FTDT. The CH340 can deliver more current which is needed while the flash process depending on the board type. The timing is also much more stable. **For boards with an USB/TTL adapter onboard this is NOT needed**
 [ESP uploader](https://github.com/srg74/ESP-uploader) |  CP2102N module. Same USB to UART converter as many recent Dev boards using. Featuring latest USB-C connector. For use with many ESP32, ESP8266, ESP8255 and Tuya based modules. 3.3V logic and 5V power pass through for custom boards.
 
+## OLED Display Setup with FLD_PIN_RST and HELTEC_VEXT_PIN
+
+Some OLED displays, particularly the SSD1306 found in boards like the Heltec WiFi LoRa 32 V3, require specific control pins for optimal operation:
+
+- **FLD_PIN_RST (Display Reset Pin):** Provides a hardware reset pulse during initialization, ensuring the display initializes correctly. Set via `-D FLD_PIN_RST=<pin_number>` in platformio_override.ini. For Heltec V3: `-D FLD_PIN_RST=21`
+
+- **HELTEC_VEXT_PIN (Power Control Pin):** Controls a switchable power rail (Vext) that powers external peripherals. This allows the display and other components to be powered down to save energy. Set via `-D HELTEC_VEXT_PIN=<pin_number>`. For Heltec V3: `-D HELTEC_VEXT_PIN=36`
+
+**Example for Heltec WiFi LoRa 32 V3:**
+```ini
+build_flags =
+  ${env.build_flags}
+  -D FLD_PIN_RST=21
+  -D HELTEC_VEXT_PIN=36
+  -D I2C_SDA=17
+  -D I2C_SCL=18
+```
+
+Refer to the compatible controllers section for the Heltec WiFi LoRa 32 V3 board details.
+
 ## Miscellaneous
 
 Sorting: Sensors, Displays, Actuators