WiFi LoRa 32 (V4) - image 1
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Heltec·Dev Board

WiFi LoRa 32 (V4)

Upgraded ESP32-S3R2 + SX1262 LoRa dev board with 2MB PSRAM, 16MB flash, 0.96" OLED, switchable FPC/IPEX 2.4G antenna, GNSS interface, and solar input. Meshtastic and LoRaWAN ready.

Starting from

$17.90

Specifications

Components

Xtensa LX7 dual-core at 240MHz with 512KB SRAM, 2MB integrated PSRAM, WiFi 802.11 b/g/n, BLE 5.0, 45 GPIOs, hardware AES/SHA/RSA crypto, and AI vector instructions.

Semtech SX1262 LoRa transceiver supporting 433/470/868/915MHz bands. Standard version: +21dBm TX; high-power variant: +28dBm TX, -137dBm RX sensitivity at SF12 BW=125kHz.

Solomon Systech SSD1306 driving the onboard 0.96-inch monochrome OLED display at 128×64 resolution via I2C.

Silicon Labs CP2102 USB-to-UART bridge enabling serial programming and debug output over USB-C.

GPIO Map

GPIO8
LoRa NSS (SPI CS)
digital-output
SPI
GPIO9
LoRa SCK
digital-output
SPI
GPIO10
LoRa MOSI
digital-outputadc
SPI
GPIO11
LoRa MISO
digital-input
SPI
GPIO12
LoRa RESET
digital-output
SPI
GPIO13
LoRa BUSY
digital-input
SPI
GPIO14
LoRa DIO1
digital-input
SPI
GPIO17
OLED SDA
digital-output
I2C
GPIO18
OLED SCL
digital-output
I2C
GPIO21
OLED RST
digital-output
I2C
GPIO35
LED (built-in)
digital-outputpwm
GPIO36
Vext (external 3.3V power control)
digital-output
GPIO3
I2C SDA (user)
digital-inputdigital-outputadctouchpwm
I2C
GPIO4
I2C SCL (user)
digital-inputdigital-outputadctouchpwm
I2C
GPIO43
UART TX
digital-output
UART
GPIO44
UART RX
digital-input
UART
GPIO1
ADC / User GPIO
digital-inputdigital-outputadctouchpwm
GPIO2
ADC / User GPIO
digital-inputdigital-outputadctouchpwm
GPIO5
ADC / User GPIO
digital-inputdigital-outputadctouchpwm
GPIO6
ADC / User GPIO
digital-inputdigital-outputadctouchpwm
GPIO7
ADC / User GPIO
digital-inputdigital-outputadctouchpwm
GPIO33
User GPIO
digital-inputdigital-outputpwm
GPIO34
User GPIO
digital-inputdigital-outputpwm
GPIO45
User GPIO (strapping)
digital-inputdigital-outputpwmstrapping
GPIO46
User GPIO (strapping)
digital-inputdigital-outputpwmstrapping
GPIO47
User GPIO
digital-inputdigital-outputpwm
GPIO48
User GPIO
digital-inputdigital-outputpwm

Overview

The WiFi LoRa 32 (V4) is Heltec's enhanced successor to the V3, upgrading the MCU to the ESP32-S3R2 which adds 2MB integrated PSRAM alongside 16MB of external flash — a significant step up for applications requiring larger buffers, bitmap rendering, or lightweight TLS/TLS stacks. The board retains the familiar 0.96-inch OLED display, SX1262 LoRa transceiver, and USB-C interface in a nearly identical 51.7 × 25.4mm footprint.

A major addition in V4 is the switchable 2.4GHz antenna system: a built-in FPC antenna for compact installations and an IPEX connector for external antennas when range or enclosure mounting demands it. The board also adds a 1.25×8P GNSS header for direct connection to a GPS/GNSS module (such as the companion L76K), and a 1.25×2P solar input accepting 4.7–6V for off-grid deployments. A high-power LoRa variant is available offering up to 28dBm TX power.

The V4 is fully compatible with Meshtastic, MeshCore, and LoRaWAN, and supports Arduino, MicroPython, PlatformIO, and ESP-IDF. Deep sleep power consumption drops below 20µA, making it well suited for battery- or solar-powered sensor nodes and mesh relay nodes.

Use Cases

6

Resources

Where to Buy

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