Power FunctionUSB power input/output Regulated 3.3 V output Ground Controlled external 3.3 V outputWhat is on the Heltec V4?

At the center of the board is the ESP32-S3R2, a dual-core microcontroller running up to 240 MHz with built-in Wi-Fi and Bluetooth.

For long-range communication, Heltec uses the SX1262 LoRa transceiver. Depending on the antenna and environment, LoRa communication can reach several kilometers. Open-area setups with suitable high-gain antennas can achieve considerably longer distances, while buildings and interference can reduce the practical range.

 Other important hardware includes:

  • 0.96-inch OLED connected through I2C
  • USB Type-C for power, programming, and serial communication
  • Li-ion/LiPo battery connector
  • Solar-panel input
  • GNSS expansion connector
  • 2.4 GHz antenna system for Wi-Fi/Bluetooth
  • Dedicated LoRa antenna connector
  • Dual-row GPIO headers
  • User and reset buttons
  • Status LEDs
  • Onboard power-management circuitry

The GNSS connector is worth noting because the V4 does not contain a GPS receiver itself. Instead, it provides an interface for connecting an external GNSS module using UART and control signals.

Pinout

Setting Up Arduino IDE

The V4 requires the Heltec ESP32 framework rather than relying only on the standard ESP32 board package.

Start by installing the latest Arduino IDE.

Then open:

File → Preferences → Additional Board Manager URLs

Add the Heltec package URL:

https://resource.heltec.cn/download/package_heltec_esp32_index.json

Next, open Boards Manager, search for Heltec ESP32, and install the latest available package.

This package provides the board definitions, ESP32-S3 support, USB configuration, LoRa pin mapping, and OLED-related configuration required by the V4.

You should also install the Heltec ESP32 Dev-Boards library from Arduino IDE's Library Manager. Install any dependencies requested by the IDE.

If the V4 Does Not Appear in Arduino IDE

A common setup problem is seeing Heltec V2 and V3 boards in the board list while the WiFi LoRa 32 V4 is missing.

This can happen when an older Heltec framework is installed.

If updating through Boards Manager does not resolve the problem, the framework can be updated manually from Heltec's GitHub repository. Download the latest release, extract it, and replace the older framework files in the Arduino packages directory.

After restarting Arduino IDE, the V4 board definition should become available.

Then go to:

Tools → Board → Heltec WiFi LoRa 32 V4

Connect the board using a USB-C cable.

Native USB: The Setting That Is Easy to Miss

The move to native USB is one of the major hardware changes in the V4.

It removes the need for a separate CP2102 USB-to-serial chip and reduces hardware complexity. However, it also means that the USB serial configuration needs attention.

If your sketch uploads successfully but nothing appears in the Serial Monitor, check:

Tools → USB CDC On Boot → Enabled

USB CDC enables serial communication over the ESP32-S3's native USB interface during boot.

This small setting can save a lot of confusion during initial testing.

Final Thoughts

The Heltec WiFi LoRa 32 V4 is interesting because it brings several functions that normally require separate modules onto one ESP32-S3 platform. The combination of LoRa, Wi-Fi, Bluetooth, OLED, battery management, solar input, native USB, and GNSS expansion makes it a practical starting point for connected embedded projects.

The main thing to remember during development is that many ESP32-S3 GPIOs are already assigned to the OLED, LoRa radio, USB, GNSS interface, and power-management circuitry.

If you want a more detailed pin-by-pin explanation and setup reference, I also documented the board in greater depth on Play with Circuit.

For anyone building a project around this board, the next useful step is to identify the GPIOs that remain available after accounting for the onboard peripherals, then build the application around those pins.