# Adafruit Feather 32u4 RFM95 LoRa (900 MHz) > Feather-format development board combining the ATmega32u4 microcontroller with an RFM95 LoRa 868/915 MHz transceiver for long-range, low-power IoT applications. ## Quick Facts - **Brand:** Adafruit - **Board Type:** dev-board - **Price:** ~$34.95 - **Product Readiness:** developer - **CPU:** AVR ATmega32u4 @ 8MHz - **CPU Architecture:** AVR - **CPU Cores:** 1 - **RAM:** 2KB SRAM - **Flash:** 32KB - **Power:** 3.7V LiPo via JST or 5V Micro-USB - **Operating Voltage:** 3.3V - **Dimensions:** 51.0 × 22.8 × 8mm - **Weight:** 5g - **Battery:** external LiPo (JST connector) - **Antenna:** U.FL/IPEX ## Connectivity - **Lora:** RFM95 LoRa 868/915 MHz (SX1276-based) ## Open Source - **Firmware:** Yes - **Schematics:** Yes - **PCB Layout:** Yes ## Compatible Firmware arduino, platformio ## Use Cases - iot - lora-mesh-networking - environmental-monitoring - asset-tracking ## Components - **undefined** (mcu): 8-bit AVR microcontroller with native USB, 32KB flash, 2KB SRAM, running at 8MHz on 3.3V — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2FAtmel-7766-8-bit-AVR-ATmega16U4-32U4_Datasheet.pdf&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) - **undefined** (radio): HopeRF RFM95 LoRa transceiver (SX1276-based) operating at 868/915 MHz with configurable spreading factor for long-range, low-power communication — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fcdn-shop.adafruit.com%2Fproduct-files%2F3179%2Fsx1276_77_78_79.pdf&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) - **undefined** (battery-charger): Microchip MCP73831 single-cell LiPo/LiIon battery charger IC providing up to 100mA charge current via USB — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2F20001984g.pdf&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) ## Protocols - **I2C**: SDA: D2, SCL: D3 - **SPI**: MOSI: D16, MISO: D14, SCK: D15, CS: D10 - **UART**: TX: D1, RX: D0 ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | D0 | RX — UART Receive | UART | digital-input, digital-output | | D1 | TX — UART Transmit | UART | digital-input, digital-output | | D2 | SDA — I2C Data | I2C | digital-input, digital-output | | D3 | SCL — I2C Clock | I2C | digital-input, digital-output, pwm | | D4 | Radio RST | GPIO | digital-input, digital-output | | D5 | GPIO / PWM | GPIO | digital-input, digital-output, pwm | | D6 | GPIO / PWM | GPIO | digital-input, digital-output, pwm | | D7 | Radio IRQ | GPIO | digital-input | | D8 | Radio CS | SPI | digital-input, digital-output | | D9 | GPIO / PWM | GPIO | digital-input, digital-output, pwm | | D10 | SPI CS / PWM | SPI | digital-input, digital-output, pwm | | D11 | GPIO / PWM | GPIO | digital-input, digital-output, pwm | | D13 | LED / PWM | GPIO | digital-input, digital-output, pwm | | D14 | MISO — SPI | SPI | digital-input, digital-output | | D15 | SCK — SPI Clock | SPI | digital-input, digital-output | | D16 | MOSI — SPI | SPI | digital-input, digital-output | | A0 | Analog Input 0 (D18) | GPIO | digital-input, digital-output, analog-input | | A1 | Analog Input 1 (D19) | GPIO | digital-input, digital-output, analog-input | | A2 | Analog Input 2 (D20) | GPIO | digital-input, digital-output, analog-input | | A3 | Analog Input 3 (D21) | GPIO | digital-input, digital-output, analog-input | | A4 | Analog Input 4 (D22) | GPIO | digital-input, digital-output, analog-input | | A5 | Analog Input 5 (D23) | GPIO | digital-input, digital-output, analog-input | ## Description ## Overview The Adafruit Feather 32u4 RFM95 is a compact, all-in-one development board that pairs the popular ATmega32u4 microcontroller with an HopeRF RFM95 LoRa transceiver operating at 868/915 MHz. Built on Adafruit's Feather form factor, it delivers the range and penetration advantages of LoRa modulation in a tiny, breadboard-friendly package suited to sensor networks, remote monitoring, and IoT deployments requiring kilometre-scale wireless links across the popular 868 MHz (Europe) and 915 MHz (North America) ISM bands. The ATmega32u4 is an 8-bit AVR microcontroller running at 8 MHz with 32KB of flash and 2KB of SRAM. It features native USB support, eliminating the need for a separate USB-to-serial chip and enabling USB HID, CDC, and MIDI device emulation out of the box. The 3.3V operating voltage ensures compatibility with modern sensors and radio modules without level shifting. The RFM95 module is based on the Semtech SX1276 silicon and supports LoRa spread-spectrum modulation with link budgets exceeding 148 dB, enabling multi-kilometre communication in open environments. Configurable spreading factors (SF7–SF12), coding rates, and bandwidths allow fine-grained trade-offs between throughput and range. The module is well supported by the RadioHead and Arduino-LoRa libraries and is compatible with LoRaWAN network stacks via the MCCI Arduino LoRaWAN library. Conforming to the Feather specification, the board measures 51.0 × 22.8 × 8 mm and includes a built-in 100 mA LiPo charger (MCP73831), a JST PH connector for a 3.7 V LiPo battery, and Micro-USB for programming and charging. Mounting holes and a U.FL/IPEX antenna connector complete the hardware. The board is fully supported by the Arduino IDE and PlatformIO, and Adafruit publishes open-source schematics and PCB layout files. ## Where to Buy - [Buy for $34.95](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3078&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3178&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fadafruit-feather-32u4-radio-with-rfm69hcw-module&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit-Feather-32u4-Radio-PCB&ref=openhardware.directory&product=adafruit-feather-32u4-rfm95&source=md-export) ## Images ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/71a24dbcb3dd.jpg) ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/c2ad35ee0153.jpg) ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/372ac37bbd79.jpg) ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/482964090403.jpg) ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/aa5dc3f76f8e.jpg) ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/a160b24cac8e.jpg) ![Adafruit Feather 32u4 RFM95 LoRa (900 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm95/24dfc4c1ffef.jpg) > **Battery Powered:** Li-Po --- [View full device page](https://openhardware.directory/devices/adafruit-feather-32u4-rfm95)