The Heltec WiFi LoRa 32 V4 is the latest ESP32-S3 development board with long-range SX1262 LoRa,
solar charging support, GNSS expansion, and improved RF performance. Designed as a drop-in
replacement for the WiFi LoRa 32 V3, it offers higher transmit power, better sensitivity,
and double the Flash storage — ideal for IoT, LoRaWAN, GPS trackers, and Meshtastic nodes.
Main Features
- Based on the ESP32-S3R2 dual-core MCU and SX1262 LoRa transceiver, supporting Wi-Fi b/g/n, Bluetooth LE, and long-range LoRa communication.
- Equipped with 2 MB PSRAM and 16 MB Flash — ideal for complex applications, rich UIs, and graphics.
- High-power LoRa output up to 28 dBm (approx. 630 mW). Low-power version also available.
- Rugged PC screen housing with integrated 2.4 GHz FPC antenna.
- Fully compatible form factor and pinout with WiFi LoRa 32 V3.
- Dedicated solar-charging input (1.25-2P) and GNSS interface (1.25-8P).
- Improved lithium battery management and safe charging circuitry.
- Ultra-low power consumption: <20 μA in deep sleep mode.
WiFi LoRa 32 V3 vs V4 – Hardware Differences
| Feature | V3 | V4 | What It Means |
|---|---|---|---|
| MCU Variant | ESP32-S3FN8 | ESP32-S3R2 (with 2 MB integrated PSRAM) | V4 has integrated PSRAM → simpler design, more stable memory performance. |
| Flash | 8 MB | 16 MB | More space on V4 for firmware, logs, and filesystem. |
| Max LoRa TX Power | 21 ± 1 dBm | 27–28 ± 1 dBm (high-power version) | V4 can output ~4× the RF power → much longer potential range. |
| RX Sensitivity | ~–134 dBm | ~–137 dBm | Slightly better receive performance → improved link budget. |
| Display Module | Fixed SSD1306 OLED | SSD1315 OLED, removable + protective front cover | V4 display is replaceable and more durable for field use. |
| Antenna Options (2.4 GHz) | On-board antenna only | FPC antenna + selectable IPEX connector | V4 supports external Wi-Fi antennas. |
| Solar Input | No | Yes (dedicated header) | V4 can be powered directly from a solar source. |
| GNSS Header | No | Yes (8-pin GNSS) | V4 supports plug-in GPS modules, ideal for trackers. |
| Power Design | Standard | Enhanced for higher TX power & peripheral power-gating | V4 supports high-power TX and more energy-aware peripheral control. |
The Heltec WiFi LoRa 32 V4 is a drop-in upgrade to the V3, offering higher LoRa transmit power, improved RF sensitivity, double the flash memory, optional external Wi-Fi antennas, solar-charging capability, and a GNSS interface. For most IoT and Meshtastic projects, V4 provides better range and efficiency while remaining fully pin-compatible with the V3.
Specifications
| Parameter | Description |
|---|---|
| MCU | ESP32-S3R2 dual-core Xtensa® LX7 |
| LoRa Chip | SX1262 |
| Frequency Range | 863–928 MHz |
| Max TX Power | 28 dBm (high-power) / 21 dBm (low-power) |
| RX Sensitivity | –137 dBm @ SF12 BW125 |
| Wi-Fi | 802.11 b/g/n, up to 150 Mbps |
| Bluetooth | Bluetooth LE, Bluetooth 5, Bluetooth Mesh |
| Memory | 384 KB ROM, 512 KB SRAM, 16 KB RTC SRAM, 2 MB PSRAM, 16 MB Flash |
| Interfaces | USB-C, battery (1.25×2), solar (1.25×2), GNSS (1.25×8), IPEX LoRa & 2.4G antennas |
| Battery | 3.3–4.4 V Li-ion / LiPo |
| Operating Temperature | –20 to 70°C |
| Dimensions | 51.7 × 25.4 × 10.7 mm |
WiFi LoRa 32 (V3) – In the Box
- 1 × WiFi LoRa 32 (V3) Module (433–510 MHz)
- 1 × LoRa Antenna
- 1 × SMA-F to IPEX Pigtail
- 1 × SH1.25×2 Battery Cable
Frequently Asked Questions (FAQ)
| Question | Answer |
|---|---|
| 1. What about the 2.4 GHz antenna? | The V4 includes an integrated 2.4 GHz FPC antenna. To use an external IPEX antenna, remove the onboard inductor (marked “①”) and short the jumper pad (marked “②”). |
| 2. What development environments are supported? | Fully supported: Arduino, MicroPython, PlatformIO and Espressif IDF. Heltec provides reference libraries and LoRaWAN examples for ESP32. |
| 3. What battery connector does it use? | A standard SH1.25 × 2 Li-ion/LiPo connector is used for the battery input. |
| 4. Is there a version without the OLED display? | Yes. Heltec offers V4 boards without the OLED for bulk and custom orders. |
| 5. Are V3 and V4 compatible? | Yes. V4 is pin-compatible with V3. Note: V4 has higher TX power, so some firmware may need minor adjustments. |
| 6. I can’t upload firmware. What should I do? | Try a different USB-C data cable. To enter bootloader mode: • Hold PRG and connect USB-C, or • Hold PRG, press RST, then release PRG. |
| 7. Why are there no “868” or “915” resistors? | The V4 hardware supports both frequency bands natively. Early versions used separate hardware; now the design is unified. |
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