# Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz) > ATSAMD21G18 ARM Cortex-M0+ Feather board with RFM69HCW sub-GHz radio at 868/915 MHz. Up to +20 dBm TX power, AES-128 encryption, 256KB flash, 32KB RAM, native USB, and built-in LiPo charger. ## Quick Facts - **Brand:** Adafruit - **Board Type:** dev-board - **Price:** ~$29.95 - **Product Readiness:** developer - **CPU:** ATSAMD21G18 ARM Cortex-M0+ @ 48 MHz - **CPU Architecture:** ARM Cortex-M0+ - **CPU Cores:** 1 - **RAM:** 32KB SRAM - **Flash:** 256KB - **Power:** 5V + LiPo - **Operating Voltage:** 3.3V - **Dimensions:** 51 × 23 × 8 mm - **Antenna:** U.FL/IPEX ## Connectivity - **Lora:** RFM69HCW 868/915MHz SX1231 (FSK/OOK, not LoRa) ## Open Source - **Firmware:** Yes - **Schematics:** Yes - **PCB Layout:** Yes ## Compatible Firmware arduino, platformio ## Use Cases - iot - long-range-sensor-network - remote-sensor-nodes - sub-ghz-communication - prototyping ## Components - **ATSAMD21G18** (mcu): ARM Cortex-M0+ at 48MHz, 256KB flash, 32KB SRAM, native USB. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2FSAM_D21_DA1_Family_DataSheet_DS40001882F.pdf&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) - **RFM69HCW** (sub-ghz-radio): HopeRF RFM69HCW 868/915MHz radio module based on SX1231, +13 to +20 dBm TX, AES-128, FSK/OOK modulation. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fcdn-shop.adafruit.com%2Fproduct-files%2F3076%2FRFM69HCW-V1.1.pdf&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) ## Protocols - **SPI**: MOSI: PA16, MISO: PA19, SCK: PA17 - **I2C**: SDA: PA22, SCL: PA23 - **UART**: TX: PA10, RX: PA11 - **RFM69 packet radio**: CS: PA06, RST: PA08, IRQ: PA09 ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | PA02 | A0 — Analog In / DAC Out | — | analog-input, analog-output | | PA05 | A1 — Analog In | — | analog-input | | PB08 | A2 — Analog In | — | analog-input | | PB09 | A3 — Analog In | — | analog-input | | PA04 | A4 — Analog In | — | analog-input | | PB02 | A5 — Analog In | — | analog-input | | PA11 | RX — UART Receive | UART | digital-input, digital-output | | PA10 | TX — UART Transmit | UART | digital-input, digital-output | | PA09 | D3 — Radio IRQ | — | digital-input, digital-output, pwm | | PA08 | D4 — Radio RST | — | digital-input, digital-output, pwm | | PA15 | D5 — GPIO / PWM | — | digital-input, digital-output, pwm | | PA20 | D6 — GPIO / PWM | — | digital-input, digital-output, pwm | | PA06 | D8 — Radio CS | SPI | digital-input, digital-output | | PA07 | D9 — GPIO / PWM / Analog | — | digital-input, digital-output, pwm, analog-input | | PA18 | D10 — GPIO / PWM | — | digital-input, digital-output, pwm | | PA16 | D11 — SPI MOSI | SPI | digital-input, digital-output | | PA19 | D12 — SPI MISO | SPI | digital-input, digital-output | | PA17 | D13 — SPI SCK / LED | SPI | digital-input, digital-output | | PA22 | SDA — I2C Data | I2C | digital-input, digital-output | | PA23 | SCL — I2C Clock | I2C | digital-input, digital-output | ## Description ## Overview\n\nThe Adafruit Feather M0 RFM69HCW 868/915 MHz combines the ATSAMD21G18 ARM Cortex-M0+ microcontroller running at 48 MHz with the HopeRF RFM69HCW sub-GHz radio module. Designed for the 868 MHz (Europe) and 915 MHz (North America) ISM bands, this Feather form-factor board makes it straightforward to add reliable long-range packet radio to battery-powered projects.\n\nThe ATSAMD21G18 provides 256KB of flash and 32KB of SRAM — significantly more than ATmega-based alternatives — along with native USB support for programming and serial communication. The RFM69HCW radio module, based on the Semtech SX1231, supports FSK and OOK modulation with hardware AES-128 encryption and transmit power adjustable from +13 to +20 dBm. A u.FL connector accepts an external antenna for optimized range.\n\nAll standard Feather peripherals are present: 20 GPIO pins, 6 analog inputs, one DAC output, 8 PWM channels, and hardware I2C, SPI, and UART. A JST connector and built-in 100mA LiPo charger make it easy to run from a rechargeable battery, while the USB port charges the battery when connected. The onboard LED on D13 doubles as a status indicator.\n\nThe RadioHead library provides a straightforward API for addressed packet communication with acknowledgment and retries. Compatible with both the Arduino IDE and PlatformIO, this board is well suited for sensor networks, remote telemetry, and any application requiring dependable sub-GHz wireless links. ## Where to Buy - [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3176&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) — 29.95 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3176&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit-Feather-M0-Radio-PCB&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fadafruit-feather-m0-radio-with-rfm69-packet-radio%2Foverview&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) - [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fcdn-shop.adafruit.com%2Fproduct-files%2F3076%2FRFM69HCW-V1.1.pdf&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw&source=md-export) ## Tags `feather`, `samd21`, `rfm69`, `packet-radio`, `868mhz`, `915mhz`, `sub-ghz`, `adafruit`, `cortex-m0` ## Images ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/8e78fc02102e.jpg) ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/5ca51ef6a781.jpg) ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/0bf922d89d39.jpg) ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/f5131c69e0ef.jpg) ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/94e1adccb9ab.jpg) ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/54024fcf25aa.jpg) ![Adafruit Feather M0 RFM69HCW Packet Radio (868/915 MHz)](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw/8475e90ff655.jpg) --- [View full device page](https://openhardware.directory/devices/adafruit-feather-m0-rfm69hcw)