# Adafruit Feather M0 RFM69HCW 433 MHz > ATSAMD21G18 ARM Cortex-M0+ Feather board with RFM69HCW sub-GHz radio at 433 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 433MHz 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-433&source=md-export) - **RFM69HCW** (sub-ghz-radio): HopeRF RFM69HCW 433MHz 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-433&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 433 MHz is the 433 MHz variant of the M0 RFM69 Feather series, targeting the 433 MHz ISM band used widely in Europe, Asia, and other regions. It combines the ATSAMD21G18 ARM Cortex-M0+ at 48 MHz with the HopeRF RFM69HCW radio module based on the Semtech SX1231. Like its 868/915 MHz sibling, this board brings ARM-class processing power to sub-GHz radio applications. The SAMD21's 256KB flash and 32KB SRAM allow more sophisticated firmware than ATmega-based alternatives. The 433 MHz frequency provides better RF propagation through walls and obstacles compared to higher frequencies. The RFM69HCW supports FSK and OOK modulation with hardware AES-128 encryption and transmit power from +13 to +20 dBm. A u.FL connector allows use of an optimized 433 MHz external antenna. The RadioHead library provides a complete API for packet radio communication with addressing and acknowledgment. All standard Feather features are present: 20 GPIO pins, 10 analog inputs (one with DAC), 8 PWM channels, hardware SPI/I2C/UART, native USB, and a built-in 100mA LiPo charger. This makes it well suited to sensor nodes and remote monitoring applications in regions where 433 MHz is the preferred ISM band. ## Where to Buy - [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3177&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw-433&source=md-export) — 24.95 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3177&ref=openhardware.directory&product=adafruit-feather-m0-rfm69hcw-433&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-433&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-433&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-433&source=md-export) ## Tags `feather`, `rfm69`, `433mhz`, `sub-ghz`, `atsamd21`, `arm-cortex-m0`, `iot`, `adafruit` ## Images ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/3e5be434ae4b.jpg) ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/3ec0fc16f213.jpg) ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/f21a7e254af9.jpg) ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/f6c0096e6807.jpg) ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/cd22fa7e3a8a.jpg) ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/9049455034c4.jpg) ![Adafruit Feather M0 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m0-rfm69hcw-433/1310dc5ade49.jpg) --- [View full device page](https://openhardware.directory/devices/adafruit-feather-m0-rfm69hcw-433)