# Heltec HRI-485X > Industrial RS-485 wireless converter with ESP32, LoRa SX1262, Ethernet, and ESPHome support. Converts RS-485/Modbus serial data to LoRa, LoRaWAN, LTE, or Ethernet for long-range industrial IoT communication. DIN rail mountable with IP65 protection and 4.5-28V wide voltage input. ## Quick Facts - **Brand:** Heltec Automation - **Board Type:** DTU - **Price:** ~$17.9 - **CPU:** Xtensa LX6 dual-core @ 240MHz, FPU, HW crypto (AES/SHA/RSA) - **CPU Architecture:** Xtensa LX6 - **CPU Cores:** 2 - **RAM:** 520KB SRAM - **Flash:** 4MB - **USB:** No - **Power:** 7-28V DC - **Operating Voltage:** 3.3V - **Operating Temp:** -40°C to +85°C - **Dimensions:** 120 × 70 × 32mm - **Weight:** 90g - **Antenna:** SMA female (LoRa) - **SD Card:** No ## Connectivity - **Wifi:** 802.11 b/g/n - **Bluetooth:** Bluetooth 4.2, BLE - **Lora:** SX1262 433/868/915MHz - **Ethernet:** 10/100 Mbps ## Use Cases - modbus-iot-gateway - industrial-rs485-communication - rs485-to-lora-bridge - rs485-to-wifi-bridge - building-management - lora-mesh-networking ## Components - **ESP32-D0WDQ6** (mcu): Xtensa LX6 dual-core processor at 240MHz with 520KB SRAM, 4MB flash, WiFi 802.11 b/g/n and Bluetooth 4.2/BLE. Provides the main processing, Ethernet MAC, and wireless connectivity for the converter. — [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-hri-485x&source=md-export) - **SX1262** (radio): Semtech SX1262 long-range, low-power sub-GHz RF transceiver supporting LoRa and FSK modulation in the 150-960MHz ISM bands. Provides +22dBm TX power with -134dBm receiving sensitivity for multi-kilometer range. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.semtech.com%2Fproducts%2Fwireless-rf%2Flora-connect%2Fsx1262&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) - **RTL8201** (ethernet-phy): Realtek RTL8201 single-chip 10/100Mbps Fast Ethernet PHYceiver connected via RMII interface, providing wired LAN connectivity for local configuration and data forwarding. — [Datasheet](https://openhardware.directory/r?to=http%3A%2F%2Frealtek.info%2Fpdf%2Frtl8201.pdf&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) - **MAX3485** (rs485-transceiver): Maxim MAX3485 half-duplex RS-485/RS-422 transceiver operating at 3.3V with up to 10Mbps data rate. Power-controlled via GPIO16 for energy-efficient RS-485 bus communication. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.analog.com%2Fen%2Fproducts%2Fmax3485.html&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) ## Protocols - **UART** (UART0): TX: GPIO33, RX: GPIO37 - **Ethernet (RMII)**: MDC: GPIO23, MDIO: GPIO18, CLK: GPIO17 - **Modbus RTU** ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | GPIO2 | HA Online LED | — | digital-output | | GPIO3 | Status LED | — | digital-output | | GPIO16 | MAX3485 Power Control | — | digital-output | | GPIO17 | Ethernet RMII CLK | Ethernet | digital-output | | GPIO18 | Ethernet MDIO | Ethernet | digital-input, digital-output | | GPIO23 | Ethernet MDC | Ethernet | digital-output | | GPIO33 | UART TX (RS-485) | UART | digital-output | | GPIO37 | UART RX (RS-485) | UART | digital-input | ## Description ## Overview The Heltec HRI-485X is an industrial-grade RS-485 wireless converter designed for bridging legacy serial devices to modern IoT networks. Built around the ESP32 MCU with an SX1262 LoRa transceiver and RTL8201 Ethernet PHY, it converts RS-485/Modbus RTU data to LoRa, LoRaWAN, LTE, or Ethernet — enabling remote monitoring and control of industrial equipment without running new cables. The device accepts 4.5-28V DC wide-range input, features IP65 environmental protection, and mounts on standard 35mm DIN rails for clean panel installations. A MAX3485 transceiver handles the RS-485 bus interface, while a built-in web configuration page (accessible via LAN at 192.168.4.1) makes setup straightforward. Multiple networking modes are supported including point-to-point, point-to-multipoint, mesh relay, and gateway configurations. Thanks to its ESP32 core, the HRI-485X can be flashed with ESPHome firmware — turning it into a native Home Assistant Modbus gateway. The ESPHome Devices database includes a ready-made configuration with Modbus sensor examples, making it easy to integrate RS-485 devices like energy meters, HVAC controllers, and industrial sensors into a smart home or building management system. Data encryption and communication keys provide security for sensitive deployments. ## Where to Buy - [Heltec Store](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fhri-485x%2F&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) — $17.90 - [Amazon](https://openhardware.directory/r?to=https%3A%2F%2Fwww.amazon.com%2FHeltec-Wireless-Converter-Reliable-HRI-4851-915MHz%2Fdp%2FB0DB27G4Z6&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) — $27.90 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fhri-485x%2F&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fdocs.heltec.org%2Fen%2Fready_to_use%2Fhri-485x%2Findex.html&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) - [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FHRI-485X%2FHRI-485x.pdf&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FHelTecAutomation&ref=openhardware.directory&product=heltec-hri-485x&source=md-export) ## Tags `rs485`, `lora`, `modbus`, `industrial`, `iot-gateway`, `esphome`, `ethernet`, `din-rail`, `esp32` ## Images ![Heltec HRI-485X](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-hri-485x/429044ba3e36.png) ![Heltec HRI-485X](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-hri-485x/36b94b0dfc18.png) ![Heltec HRI-485X](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-hri-485x/6b8b9b582db2.png) ![Heltec HRI-485X](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-hri-485x/122dfc8b1e4d.png) --- [View full device page](https://openhardware.directory/devices/heltec-hri-485x)