# Adafruit Feather 32u4 RFM69HCW (868/915 MHz) > Feather-format development board combining the ATmega32u4 microcontroller with an RFM69HCW 868/915 MHz packet radio for low-power sub-GHz wireless applications. ## Quick Facts - **Brand:** Adafruit - **Board Type:** dev-board - **Price:** ~$24.95 - **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:** RFM69HCW 868/915 MHz sub-GHz packet radio ## 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-rfm69hcw&source=md-export) - **undefined** (radio): HopeRF RFM69HCW sub-GHz packet radio transceiver operating at 868/915 MHz with up to +20 dBm output and AES-128 encryption — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fcdn.sparkfun.com%2Fdatasheets%2FWireless%2FGeneral%2FRFM69HCW-V1.1.pdf&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw&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-rfm69hcw&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 RFM69HCW is a compact, all-in-one development board that pairs the popular ATmega32u4 microcontroller with an HopeRF RFM69HCW 868/915 MHz packet radio transceiver. Built on Adafruit's Feather form factor, it brings long-range sub-GHz wireless communication to a tiny, breadboard-friendly package, making it ideal for sensor nodes, wireless telemetry, and mesh network deployments where low power consumption is critical. 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 RFM69HCW radio module operates in the 868 MHz (Europe) and 915 MHz (North America) ISM bands, delivering up to +20 dBm output power and a receiver sensitivity of –120 dBm. It supports packet-based communication with built-in AES-128 encryption, CRC error checking, and RSSI measurement, making it well suited for point-to-point links, star topologies, and mesh networks using libraries such as RadioHead or the Adafruit fork of LowPowerLab's RFM69 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 $24.95](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3076&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw&source=md-export) ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3076&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw&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-rfm69hcw&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-rfm69hcw&source=md-export) ## Images ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/50cdedf15845.jpg) ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/dc6663a95cd2.jpg) ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/96746f3ee6aa.jpg) ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/d3038f8747d8.jpg) ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/7ec0c54cd6f7.jpg) ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/ed10e57bc062.jpg) ![Adafruit Feather 32u4 RFM69HCW (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw/e2e25284396a.jpg) > **Battery Powered:** Li-Po --- [View full device page](https://openhardware.directory/devices/adafruit-feather-32u4-rfm69hcw)