# Heltec Wireless Bridge > ESP32 + SX1276 LoRa multi-protocol bridge in an aluminum enclosure, converting between WiFi, Bluetooth, and LoRa with 8MB flash and 8MB PSRAM. ## Quick Facts - **Brand:** Heltec - **Board Type:** wireless-bridge - **Price:** ~$28.9 - **CPU:** Xtensa LX6 dual-core @ 240MHz, FPU, HW crypto (AES/SHA/RSA) - **CPU Architecture:** Xtensa LX6 - **CPU Cores:** 2 - **RAM:** 520KB SRAM - **PSRAM:** 8MB (QSPI) - **Flash:** 8MB - **USB:** Micro-USB (CP2102) - **Power:** 5V via Micro-USB,3.7V LiPo - **Operating Voltage:** 3.3V - **Operating Temp:** -20°C to +70°C - **Dimensions:** 66 × 30 × 15mm - **Weight:** 140g - **Battery:** User-supplied LiPo (1.25mm JST) - **Antenna:** SMA female (x2) - **SD Card:** No ## Connectivity - **Wifi:** 802.11 b/g/n - **Bluetooth:** v4.2 BR/EDR, BLE - **Lora:** SX1276 433/868/915MHz ## Certifications CE ## Use Cases - lora-wifi-bridge - lora-ble-bridge - lora-mesh-networking - meshtastic-mesh - lorawan-node - iot-gateway ## Components - **ESP32-D0WDQ6** (mcu): Xtensa LX6 dual-core MCU running at 240MHz with integrated WiFi 802.11 b/g/n and Bluetooth 4.2 BR/EDR + BLE, 520KB SRAM, hardware crypto acceleration. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32_datasheet_en.pdf&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - **SX1276** (radio): Semtech LoRa transceiver covering 137-1020MHz with +18dBm TX power and -135dBm RX sensitivity, supporting LoRa and FSK modulation for long-range communication. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.semtech.com%2Fproducts%2Fwireless-rf%2Flora-connect%2Fsx1276&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - **CP2102** (usb-uart): Silicon Labs single-chip USB-to-UART bridge providing programming and serial debug interface via Micro-USB port. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.silabs.com%2Fdocuments%2Fpublic%2Fdata-sheets%2FCP2102-9.pdf&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - **ESP-PSRAM64H** (memory): Espressif 64Mbit (8MB) SPI PSRAM chip providing external memory for data buffering and protocol translation workloads. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp-psram64_esp-psram64h_datasheet_en.pdf&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - **TP4054** (battery-charger): Standalone linear Li-Ion battery charger IC providing constant-current/constant-voltage charging for the internal LiPo battery via the 1.25mm JST connector. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fmedia.digikey.com%2Fpdf%2FData%2520Sheets%2FUTD%2520Semi%2520PDFs%2FTP4054.pdf&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - **AO3401** (power-management): Alpha & Omega Semiconductor P-channel MOSFET used for power path switching between USB and battery sources. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.alldatasheet.com%2Fdatasheet-pdf%2Fpdf%2F216396%2FAOSMD%2FAO3401.html&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) ## Protocols - **SPI** (VSPI): SCK: GPIO5, MOSI: GPIO27, MISO: GPIO19, SS: GPIO18 - **I2C**: SDA: GPIO21, SCL: GPIO22 - **UART** (UART0): TX: GPIO1, RX: GPIO3 - **LoRa**: SCK: GPIO5, MOSI: GPIO27, MISO: GPIO19, NSS: GPIO18, RST: GPIO14, DIO0: GPIO26, DIO1: GPIO35, DIO2: GPIO34 - **PWM** ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | GPIO0 | Boot / User Button | Digital | digital-input, digital-output, pwm, strapping | | GPIO1 | UART0 TX | UART | digital-input, digital-output, pwm | | GPIO3 | UART0 RX | UART | digital-input, digital-output, pwm | | GPIO5 | SPI SCK / LoRa SCK | SPI | digital-input, digital-output, pwm | | GPIO14 | LoRa RST | LoRa | digital-input, digital-output, pwm, adc, touch | | GPIO18 | SPI SS / LoRa NSS | SPI | digital-input, digital-output, pwm | | GPIO19 | SPI MISO / LoRa MISO | SPI | digital-input, digital-output, pwm | | GPIO21 | I2C SDA / Vext Control | I2C | digital-input, digital-output, pwm | | GPIO22 | I2C SCL / LoRa LED | I2C | digital-input, digital-output, pwm | | GPIO23 | WiFi LED | Digital | digital-input, digital-output, pwm | | GPIO25 | Built-in LED / BLE LED | Digital | digital-input, digital-output, pwm, dac | | GPIO26 | LoRa DIO0 (IRQ) | LoRa | digital-input, digital-output, pwm, dac, adc | | GPIO27 | SPI MOSI / LoRa MOSI | SPI | digital-input, digital-output, pwm, adc, touch | | GPIO34 | LoRa DIO2 | LoRa | digital-input, input-only, adc | | GPIO35 | LoRa DIO1 | LoRa | digital-input, input-only, adc | ## Description ## Overview The Heltec Wireless Bridge is a compact multi-protocol communication device built around the ESP32-D0WDQ6 dual-core MCU and Semtech SX1276 LoRa transceiver. Housed in a high-strength aluminum alloy enclosure measuring just 66 x 30 x 15mm, it is designed to bridge between WiFi, Bluetooth, and LoRa radio protocols — enabling scenarios where data from one wireless domain needs to reach another. The board features 8MB SPI flash and 8MB PSRAM (ESP-PSRAM64H), giving it ample memory for buffering and processing protocol translations. Two external SMA antenna connectors — one for LoRa (sub-GHz) and one for 2.4GHz WiFi/Bluetooth — provide strong RF performance. The SX1276 supports frequency bands from 433MHz to 928MHz with up to +18dBm transmit power and -135dBm receiver sensitivity, making it suitable for long-range LoRa deployments. Power is supplied via Micro-USB through the integrated CP2102 USB-to-UART bridge, which also serves as the programming interface. An internal 1.25mm JST lithium battery connector with TP4054 charge management allows portable battery-powered operation, though accessing the battery connector requires opening the enclosure. The device includes CE certification, ESD protection, short-circuit protection, and RF shielding for reliable field deployment. The Wireless Bridge is supported in the Heltec Arduino development framework with a dedicated board definition, and Heltec provides a pre-built Meshtastic firmware binary. WiFi and Bluetooth can operate simultaneously, making it well-suited for protocol bridging, mesh networking, and IoT gateway applications. ## Where to Buy - [Heltec Store](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fwireless-bridge%2F&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) — 28.90 - [Amazon](https://openhardware.directory/r?to=https%3A%2F%2Fwww.amazon.com%2FHeltec-Development-Bluetooth-Compatible-902-928MHz%2Fdp%2FB0D3X2CZRZ&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) — 28.90 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fwireless-bridge%2F&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FHeltec-Aaron-Lee%2FWiFi_Kit_series&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fwiki.heltec.org%2Fdocs%2Fdevices%2Fopen-source-hardware%2Fesp32-series%2Flora-32%2Fwireless-bridge%2Fproduct-usage-guide%2F&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FWireless_Bridge%2Fbridge.pdf&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) - [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FWireless_Bridge%2FSchematic_Diagram_HTIT-WB_V0.2.pdf&ref=openhardware.directory&product=heltec-wireless-bridge&source=md-export) ## Tags `esp32`, `lora`, `wifi`, `bluetooth`, `bridge`, `meshtastic`, `lorawan`, `heltec` ## Images ![Heltec Wireless Bridge](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-wireless-bridge/28eed46f9e79.png) ![Heltec Wireless Bridge](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-wireless-bridge/c6ffac9ff31f.png) > **Battery Powered:** true --- [View full device page](https://openhardware.directory/devices/heltec-wireless-bridge)