Seeeduino XIAO - Keyboard Optimized


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Keyboard Optimized

Due to the limited memory and flash of the ATSAMD21G18, an optimized build of CircuitPython is needed for keyboard/keypad/macropad projects. The following modules are made available:

  • keypad for handing buttons and key matrices
  • rotaryio for handling rotary encoders
  • usb_hid for sending HID messages to the computer
  • adafruit_hid (frozen module) for configuring your Xiao as a keyboard

Note that a number of modules are removed to make space for those listed above. It is assumed that a keyboard or macropad doesn’t have sensors. As such, these modules are not included:

  • busio needed for I2C, SPI and UART
  • pulseio needed some sensors
  • onewireio needed for 1-wire devices

If you need one of the modules removed or if you want to absolutely be sure that you don’t run out of memory, consider using a better processor (RP2040 for example).

This build was tested with a 30 keys macropad which is the largest matrix the XIAO allows for (5x6 matrix = 11 GPIOs).

Seeduino XIAO:

SEEED Studio’s Seeeduino XIAO is a minimal, low-cost board that uses the Atmel c, a powerful 32-bit ARM Cortex®-M0+ processor running at 48MHz with 256KB Flash and 32KB SRAM. The board is 20 x 17.5mm in size which is perfect for wearable devices and small projects. It has multiple interfaces including DAC output, SWD Bonding pad interface, I2C, UART and SPI interfaces. It’s compatible with both Arduino IDE and CircuitPython and uses a USB-C connector.


  • CPU: ARM Cortex-M0+ CPU (SAMD21G18) running at up to 48MHz
  • Flash Memory: 256KB
  • SRAM: 32KB
  • Digital I/O pins: 11
  • Analog I/O pins: 11
  • I2C interfaces: 1
  • SPI interfaces: 1
  • UART interfaces: 1
  • USB Type-C connector for transferring code and power
  • Power requirements: 3.3V/5V DC
  • Dimensions 20 × 17.5 × 3.5 mm

Note: This microcontroller runs at 3.3V logic. Using a 5V device may damage the chip or device.

For power supply pins: The built-in DC-DC converter circuit is able to change 5V voltage into 3.3V, which allows you to power the device with a 5V supply via the VIN pin or 5V pin.



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Absolute Newest

Every time we commit new code to CircuitPython we automatically build binaries for each board and language. The binaries are stored on Amazon S3, organized by board, and then by language. Try them if you want the absolute latest and are feeling daring or want to see if a problem has been fixed.

Past Releases

All previous releases are listed on GitHub, with release notes, and are available for download from Amazon S3. They are handy for testing, but otherwise we recommend using the latest stable release. Some older GitHub release pages include the same binaries for downloading. But we have discontinued including binaries as assets on newer release pages because of the large number of files for each release.