I have been using the ATmega328P TQFP32 chip for quite a while and I would like to try something new. I came across the ATSAMD21G18 used by Arduino Zero and M0. However, there aren't any information online regarding how to develop a standalone, very basic setup of it.

Previously, I have used...

  • ATmega328P TQFP32

  • For the crystal: 16Mhz and 22pF caps

  • For bootloading: 10 11 12 13 for Arduino ISP

  • For uploading programs: TX and RX of an Arduino Uno with its chip removed.

For the ATSAMD21G18, I am also looking for a similar setup. I checked out the Sparkfun Mini breakout schematics, but I am not good at reading them and there seems to be a lot of components just for protection and to make it more stable, which I don't need as you can probably know from the setup I used for the 328.


What are the basic required components for it to work properly?

For bootloading, am I required to use the Atmel Ice? If so, what are the pins and components needed for burning the Arduino Zero bootloader?

For uploading a program, am I required to use the USB functionality built in? How can I use it (components pins and connections)? Can I use Arduino ISP using an Arduino Zero?

Finally, what should I bear in mind when switching from an ATmega328P to an ATSAMD21G18?

Thanks in advance!

  • Datasheet says? Dec 9, 2016 at 9:28
  • Google Samd21 xplained pro. It's got a similar chip but with more features. It also has an on board debugger/programmer.
    – PhillyNJ
    Feb 22, 2017 at 11:22

1 Answer 1


This seems to be the simples form of the Arduino M0 I could find.

From this tutorial site

The ICE programmmer makes it very easy to program and all you need is the SWD pins to program the bootloader.

ISP is for AVR chips where as with ARM chips like SAMD21 you will need to use JTAG/SWD to program it.

I am also try to make a home brew Zero but I am getting stuck after the bootloader where the board just does not want to expose a Serial port.

Basic M0

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