# Adafruit Feather M0 RFM69HCW 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:** ~$24.95 - **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, circuitpython ## 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%2Fwww.adafruit.com%2Fimages%2Fproduct-files%2F2772%2Fatmel-42181-sam-d21_datasheet.pdf&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw-868-915&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-868-915&source=md-export) ## Protocols - **SPI**: MOSI: PA16, MISO: PA19, SCK: PA17 - **I2C**: SDA: PA22, SCL: PA23 - **UART**: TX: PA10, RX: PA11 - **RFM69 packet radio**: ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | PA11 | RX — UART Receive | UART | digital-input, digital-output | | PA10 | TX — UART Transmit | UART | digital-input, digital-output | | PA15 | D5 — GPIO / PWM | — | digital-input, digital-output, pwm | | PA20 | D6 — GPIO / PWM | — | digital-input, digital-output, pwm | | 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 | | PA02 | A0 — Analog In / DAC Out | — | analog-input, analog-output | | PB08 | A1 — Analog In | — | analog-input | | PB09 | A2 — Analog In | — | analog-input | | PA04 | A3 — Analog In | — | analog-input | | PA05 | A4 — Analog In | — | analog-input | | PB02 | A5 — Analog In | — | analog-input | ## Description ## Overview The Adafruit Feather M0 RFM69HCW (868/915 MHz) is the ARM-powered upgrade to the AVR-based Feather 32u4 RFM69 series. It pairs the ATSAMD21G18 ARM Cortex-M0+ at 48 MHz with the HopeRF RFM69HCW radio module (SX1231-based), delivering significantly more processing power and memory while maintaining the same compact Feather form factor. The SAMD21's 256KB of flash and 32KB of SRAM give Arduino sketches much more room to implement complex protocols, data processing, or sensor fusion on the same board that handles radio communication. Native USB support allows the board to enumerate as a serial port, HID device, or MIDI interface without additional silicon. The RFM69HCW radio operates in the 868 MHz (Europe) or 915 MHz (Americas) ISM bands with hardware AES-128 encryption and adjustable transmit power from +13 to +20 dBm (100mW peak). A u.FL connector accommodates external antennas for extended range. The RadioHead library provides a straightforward API for addressed packet networks with automatic acknowledgment. Power management is handled by a built-in 100mA LiPo charger with JST connector, enabling fully wireless operation from a single-cell LiPo battery charged via Micro-USB. With 20 GPIO pins, 10 analog inputs, 8 PWM channels, and hardware serial/I2C/SPI, this is a capable platform for long-range, low-power sensor network nodes. ## 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-868-915&source=md-export) — 24.95 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3176&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw-868-915&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit-Feather-M0-RFM-LoRa-PCB&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw-868-915&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-868-915&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-868-915&source=md-export) ## Tags `feather`, `rfm69`, `sub-ghz`, `868mhz`, `915mhz`, `atsamd21`, `arm-cortex-m0`, `iot`, `adafruit` ## Images ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/2b9f76b3ae17.jpg) ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/5ca51ef6a781.jpg) ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/b4ac321342ef.jpg) ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/df42373794c6.jpg) ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/85b5ba81c8ce.jpg) ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/c76222e79323.jpg) ![Adafruit Feather M0 RFM69HCW 868/915 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-868-915/83ff3e6ecad0.jpg) --- [View full device page](https://openhardware.directory/devices/adafruit-feather-m0-rfm69hcw-868-915)