# Adafruit Feather 32u4 RFM69HCW 433 MHz > ATmega32u4 Feather board with RFM69HCW sub-GHz radio at 433 MHz with up to +20 dBm transmit power, AES-128 encryption, and built-in LiPo charger for long-range sensor networks in the 433 MHz ISM band. ## Quick Facts - **Brand:** Adafruit - **Board Type:** dev-board - **Price:** ~$24.95 - **Product Readiness:** developer - **CPU:** ATmega32u4 @ 8 MHz - **CPU Architecture:** AVR 8-bit - **CPU Cores:** 1 - **RAM:** 2.5KB SRAM - **Flash:** 32KB - **Power:** 5V + LiPo - **Operating Voltage:** 3.3V - **Dimensions:** 51 × 23 × 8 mm - **Weight:** 5.5g - **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 ## Use Cases - iot - long-range-sensor-network - remote-sensor-nodes - sub-ghz-communication - prototyping ## Components - **ATmega32u4** (mcu): 8-bit AVR microcontroller at 8MHz, 3.3V, native USB, 32KB flash, 2.5KB SRAM. — [Datasheet](https://openhardware.directory/r?to=http%3A%2F%2Fwww.atmel.com%2FImages%2FAtmel-7766-8-bit-AVR-ATmega16U4-32U4_Datasheet.pdf&ref=openhardware.directory&product=adafruit-feather-32u4-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-32u4-rfm69hcw-433&source=md-export) ## Protocols - **SPI**: MOSI: D16, MISO: D14, SCK: D15 - **I2C**: SDA: D2, SCL: D3 - **UART**: TX: D1, RX: D0 - **RFM69 packet radio**: ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | D0 | RX — UART Receive | UART | digital-input, digital-output | | D1 | TX — UART Transmit | UART | digital-input, digital-output | | D5 | D5 — GPIO / PWM | — | digital-input, digital-output, pwm | | D6 | D6 — GPIO / PWM | — | digital-input, digital-output, pwm | | D9 | D9 — GPIO / PWM / Analog | — | digital-input, digital-output, pwm, analog-input | | D10 | D10 — GPIO / PWM | — | digital-input, digital-output, pwm | | D16 | D11/MOSI — SPI MOSI | SPI | digital-input, digital-output | | D14 | D12/MISO — SPI MISO | SPI | digital-input, digital-output | | D15 | D13/SCK — SPI Clock / LED | SPI | digital-input, digital-output | | D2 | SDA — I2C Data | I2C | digital-input, digital-output | | D3 | SCL — I2C Clock | I2C | digital-input, digital-output | | D15 | A0 — Analog In | — | analog-input | | D4 | A1 — Analog In | — | analog-input | | D5 | A2 — Analog In | — | analog-input | | D12 | A3 — Analog In | — | analog-input | | D24 | A4/SDA — Analog In / I2C SDA | I2C | analog-input, digital-input, digital-output | | D25 | A5/SCL — Analog In / I2C SCL | I2C | analog-input, digital-input, digital-output | ## Description ## Overview The Adafruit Feather 32u4 RFM69HCW 433 MHz is the 433 MHz variant of Adafruit's sub-GHz radio Feather, targeting the 433 MHz ISM band used widely in Europe, Asia, and other regions. It combines the ATmega32u4 at 8 MHz with the HopeRF RFM69HCW radio module based on the Semtech SX1231. At 433 MHz, the radio achieves lower free-space path loss compared to 868/915 MHz, resulting in better penetration through walls and longer range. The RFM69HCW supports FSK and OOK modulation, AES-128 hardware encryption, and transmit power from +13 to +20 dBm (up to 100mW). A u.FL antenna connector allows attaching an optimized 433 MHz antenna. The board shares all the same Feather features: 20 GPIO pins, 10 analog inputs, 7 PWM channels, hardware I2C/SPI/UART, native USB, and a built-in 100mA LiPo charger. The RadioHead library for Arduino makes it easy to build addressed packet networks, automatic acknowledgment, and reliable point-to-point or small mesh communication systems. This variant is ideal for deployments in regions where 433 MHz is permitted for unlicensed ISM use, or for applications that benefit from the improved penetration characteristics of the lower frequency band. ## Where to Buy - [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3077&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw-433&source=md-export) — 24.95 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3077&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw-433&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit-Feather-32u4-RFM-LoRa-PCB&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw-433&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fadafruit-feather-32u4-radio-with-rfm69hcw-module%2Foverview&ref=openhardware.directory&product=adafruit-feather-32u4-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-32u4-rfm69hcw-433&source=md-export) - [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fcdn-learn.adafruit.com%2Fassets%2Fassets%2F000%2F031%2F603%2Fmedium800%2Ffeather_schem.png&ref=openhardware.directory&product=adafruit-feather-32u4-rfm69hcw-433&source=md-export) ## Tags `feather`, `rfm69`, `433mhz`, `sub-ghz`, `atmega32u4`, `iot`, `sensor-network`, `adafruit` ## Images ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/68b98f77222d.jpg) ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/3cdc3e0dd2d5.jpg) ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/0b63027a1bc0.jpg) ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/b9460d7d555d.jpg) ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/b4503b2ca2e5.jpg) ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/8d346023833d.jpg) ![Adafruit Feather 32u4 RFM69HCW 433 MHz](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-32u4-rfm69hcw-433/de67d865d108.jpg) --- [View full device page](https://openhardware.directory/devices/adafruit-feather-32u4-rfm69hcw-433)