--- title: Introducing Cygnet - The New STM32 Feather MCU from Blues description: Cygnet is a new Feather-compatible host microcontroller from Blues - supporting Arduino, C, C++, and soon CircuitPython. source_url: https://dev.blues.io/blog/introducing-cygnet-stm32-feather-blues/ canonical_url: https://dev.blues.io/blog/introducing-cygnet-stm32-feather-blues/ markdown_url: https://dev.blues.io/blog/introducing-cygnet-stm32-feather-blues.md --- # Introducing Cygnet - The New STM32 Feather MCU from Blues ![Introducing Cygnet - The New STM32 Feather MCU from Blues banner](https://dev.blues.io/images/blog/posts/introducing-cygnet/banner.png?v=d96c1520) December 18, 2024 ## Cygnet is a new Feather-compatible host microcontroller from Blues - supporting Arduino, C, C++, and soon CircuitPython. - [Announcement](https://dev.blues.io/blog/tag/announcement) [![Rob Lauer](https://dev.blues.io/images/blog/authors/rob-lauer.jpg?v=57fb21a7)](https://dev.blues.io/blog/author/rob-lauer/) [Rob LauerSenior Director of Developer Relations](https://dev.blues.io/blog/author/rob-lauer/) [Cygnet](https://shop.blues.com/products/cygnet?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link) takes flight today! While in real life a cygnet is a baby swan, at Blues we prefer to think of our Cygnet as a less expensive, but perfectly capable, cousin to the [Blues Swan](https://shop.blues.com/collections/swan/products/swan?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link). ![blues cygnet front view](https://dev.blues.io/images/blog/posts/introducing-cygnet/cygnet-front.jpg?v=6716c87f) ## What is Blues Cygnet? Like the Blues Swan, Cygnet is an [Adafruit Feather-compatible](https://learn.adafruit.com/adafruit-feather/feather-specification) host based on an STM32 microcontroller. It's a perfect companion to the [Blues Notecarrier F](https://shop.blues.com/products/notecarrier-f?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link), which includes a Feather-compatible socket. ![blues cygnet on notecarrier f](https://dev.blues.io/images/blog/posts/introducing-cygnet/cygnet-carr-f.jpg?v=81984db5) Cygnet is built around [ST's ultra low-power STM32L433](https://www.st.com/en/microcontrollers-microprocessors/stm32l433cc.html) and offers 256KB of flash memory and 64KB of RAM. Like Swan, Cygnet has an onboard Qwiic/StemmaQT connector, but also provides a USB C connector (instead of micro USB). The board has three independent power options – USB, battery, or line power – and provides a software-switchable 2 Amp regulator for powering external sensors. When operating in its low-power operating mode, **the entire Cygnet board draws only 4uA** while retaining all of its memory, making it ideal for battery-powered devices. ## Key Cygnet Specs and Comparison with Swan Cygnet includes the following features and capabilities: - Ultra low-power Arm Cortex-M4 core clocked at 80Mhz - STM32L433-based microcontroller - 256KB of flash and 64KB of RAM - Feather-compatible GPIO & Bus pins including: - RX & TX - SDA & SCL - SCK/MOSI/MISO - I2C - Qwiic/StemmaQT connector - USB C connector - Support for [Notecard Outboard Firmware Update](https://dev.blues.io/notehub/host-firmware-updates/notecard-outboard-firmware-update.md) When **comparing Cygnet and Swan** for your specific products' needs, consult the following table: | | Swan | Cygnet | | ---------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------- | | SOM Type | [STM32L4R5](https://www.st.com/resource/en/datasheet/stm32l4r5vi.pdf) | [STM32L433](https://www.st.com/resource/en/datasheet/stm32l433cc.pdf) | | Cortex CPU Type | M4 | M4 | | Flash Size | 2048KB | 256KB | | SRAM Size | 640KB | 64KB | | STOP2 RTC XTAL | ✅ | ✅ | | STOP2 Sleep Current | 8uA | 4uA | | QWIIC Connector | ✅ | ✅ | | Cortex Debug Connector | ✅ | ✅ | | 3V3 Output Enable | ✅ | ✅ | | 3V3 Output Capacity | 2A | 2A | | USB Connector Type | Micro USB | USB C | | PCB Pin Castellations | ✅ | ✅ | | PCB Pins | 65 | 28 | | [Notecard Outboard Firmware Update](https://dev.blues.io/notehub/host-firmware-updates/notecard-outboard-firmware-update.md) | ✅ | ✅ | | [Arduino Native Debugging](https://github.com/stm32duino/Arduino_Core_STM32/wiki/How-to-debug) | ✅ | ✅ | | Price | [$25](https://shop.blues.com/collections/feather-mcu/products/swan?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link) | [$15](https://shop.blues.com/collections/feather-mcu/products/cygnet?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link) | ## Programming Cygnet ![blues cygnet supported languages](https://dev.blues.io/images/blog/posts/introducing-cygnet/cygnet-lang.png?v=8510e1d2) Cygnet ships today with support for C/C++ and Arduino (with CircuitPython support coming soon!). You can program Cygnet using [Arduino IDE](https://www.arduino.cc/en/software), [STM32CubeIDE](https://www.st.com/en/development-tools/stm32cubeide.html) with an optional SWD programmer, or [PlatformIO](https://platformio.org/) (coming soon!). ### Debugging Cygnet Since Cygnet includes a CORTEX Debug connector, you can take advantage of debugging frameworks and tooling such as STLINK, JLink, OpenOCD, or GDB. What's more, like Swan, Cygnet supports step debugging with [Arduino Native Debugging](https://github.com/stm32duino/Arduino_Core_STM32/wiki/How-to-debug) on Arduino IDE v2 using an attached [STLINK programmer/debugger](https://shop.blues.com/collections/accessories/products/stlink-v3mini?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link). ![debugging sketch on cygnet](https://dev.blues.io/images/blog/posts/introducing-cygnet/cygnet-debug.png?v=9d6584cc) ## Getting Started with Cygnet Buy your own flock of Cygnets on the [Blues shop](https://shop.blues.com/products/cygnet?utm_source=dev-blues\&utm_medium=web\&utm_campaign=store-link) today for only $15 each. While you're waiting, peruse the [Cygnet datasheet](https://dev.blues.io/datasheets/cygnet-datasheet/cygnet-v1-2.md) and [follow the Arduino IDE quickstart](https://dev.blues.io/quickstart/cygnet-quickstart.md) when your Cygnet arrives. Happy Hacking! 🦢