Maker Zero SAMD21

by Cytron Technologies

Image of Board

Do you need a powerful microcontroller with low power consumption for your project? Introducing Maker Zero SAMD21, a development board based on the famous ATSAMD21 chip featuring a 32-bit ARM Cortex® M0+ core.

Maker Zero SAMD21 is packed with convenient yet exciting features such as a servo ports, grove ports, GPIO LED indicators, RGB LEDs, programmable push buttons and a piezo buzzer. It has the same form factor as Arduino Uno and compatible with Arduino Zero.

The SAMD21 chip offers higher performance, enabling project opportunities for a variety of devices, and as a great educational tool for learning 32-bit applications. The SAMD21 chip applications span from smart IoT devices, wearable technology, high-tech automation, to robotics.

The Maker Zero SAMD21 is shipped with bootloader from Adafruit that accepts code from Arduino IDE. The bootloader also allows you to easily change the board to CircuitPython mode by double-tapping the reset button and copying the .uf2 file that contains CircuitPython firmware into the board.

Technical details

  • Arduino Uno form factor
  • Compatible with Arduino Zero
  • Powered by Atmel’s ATSAMD21
  • Arm Cortex-M0+ processor
    • Up to 48MHz operating frequency
    • 32KB of SRAM
    • 256KB of Flash memory
  • 8x Grove Ports (Digital I/O, PWM Output, UART, I2C, Analog Input)
  • 4x Servo Ports
  • 17x Status indicator LEDs for GPIOs
  • 1x Piezo buzzer with mute switch
  • 2x Push button
  • 2x RGB LEDs (WS2812 Neopixel)
  • 1x Maker Ports, compatible with Qwiic, STEMMA QT, Grove (via conversion cable)
  • Support Arduino IDE, CircuitPython



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CircuitPython 8.2.6

This is the latest stable release of CircuitPython that will work with the Maker Zero SAMD21.

Use this release if you are new to CircuitPython.

Release Notes for 8.2.6

Built-in modules available: analogio, array, board, builtins, busio, busio.SPI, busio.UART, collections, digitalio, math, microcontroller, neopixel_write, nvm, os, pwmio, rainbowio, random, rotaryio, rtc, storage, struct, supervisor, sys, time, touchio, usb_cdc, usb_hid, usb_midi

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. These releases are even newer than the development release listed above. Try them if you want the absolute latest and are feeling daring or want to see if a problem has been fixed.

Previous Versions of CircuitPython

All previous releases of CircuitPython are available for download from Amazon S3 through the button below. For very old releases, look in the OLD/ folder for each board. Release notes for each release are available at GitHub button below.

Older releases are useful for testing if you something appears to be broken in a newer release but used to work, or if you have older code that depends on features only available in an older release. Otherwise we recommend using the latest stable release.

Update UF2 Bootloader

Latest version: v3.15.0

The bootloader allows you to load CircuitPython, MakeCode, and Arduino programs. The bootloader is not CircuitPython. You can check the current version of your bootloader by looking in the INFO_UF2.TXT file when the BOOT drive is visible (FEATHERBOOT, CPLAYBOOT, etc.).

It is not necessary to update your bootloader if it is working fine. Read the release notes on GitHub to see what has been changed. In general, we recommend you not update the bootloader unless you know there is a problem with it or a support person has asked you to try updating it.

To update, first save the contents of CIRCUITPY, just in case. Then double-click the reset button to show the BOOT drive. Drag the update-bootloader .uf2 file to the BOOT drive. Wait a few tens of seconds for the bootloader to update; the BOOT drive will reappear. After you update, check INFO_UF2.TXT to verify that the bootloader version has been updated. Then you will need to reload CircuitPython.