---
product_id: 203224713
title: "XIAO SAMD21"
brand: "seeed studio"
price: "€ 35.84"
currency: EUR
in_stock: false
reviews_count: 9
category: "Seeed Studio"
url: https://www.desertcart.ie/products/203224713-xiao-samd21
store_origin: IE
region: Ireland
---

# 48MHz ARM Cortex-M0+ CPU - 3x faster than Arduino Uno Tiny 20mm x 17.5mm footprint - fits anywhere 14 GPIO pins with UART, I2C, SPI & USB-C XIAO SAMD21

**Brand:** seeed studio
**Price:** € 35.84
**Availability:** ❌ Out of Stock

## Summary

> 🚀 Tiny Tech, Massive Possibilities — Power Your Next Wearable Revolution!

## Quick Answers

- **What is this?** XIAO SAMD21 by seeed studio
- **How much does it cost?** € 35.84 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.ie](https://www.desertcart.ie/products/203224713-xiao-samd21)

## Best For

- seeed studio enthusiasts

## Why This Product

- Trusted seeed studio brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Arduino IDE Ready:** 100% compatible with Arduino IDE for rapid prototyping and effortless coding.
- • **Plug & Play USB-C:** Modern USB Type-C interface for seamless connectivity and HID device support.
- • **Compact Yet Loaded:** Smallest Arduino-compatible board packing 14 versatile GPIO pins and multiple communication protocols.
- • **Wearable & Low Power:** Designed for tiny, power-efficient wearable devices and innovative DIY projects.
- • **Blazing Fast Processing:** 48MHz 32-bit ARM Cortex-M0+ CPU powers complex projects with ease.

## Overview

The Seeed Studio XIAO SAMD21 is the smallest Arduino-compatible microcontroller board featuring a 48MHz ARM Cortex-M0+ CPU, 256KB flash memory, and 32KB SRAM. Despite its thumb-sized footprint (20mm x 17.5mm), it offers 14 GPIO pins with support for UART, I2C, SPI, and a USB Type-C port, making it ideal for wearable devices, rapid prototyping, and compact DIY electronics. Fully compatible with Arduino IDE, it delivers high performance in a power-efficient package favored by makers and professionals alike.

## Description

desertcart.com: Seeed Studio XIAO SAMD21 - Smallest Arduino Microcontroller with Rich Interfaces for Wearable Devices, 100% Arduino IDE Compatible, 3pcs : Electronics

Review: My go to for sooo many reasons - I bought 3 of these a couple years ago to play around with. At the time, it was just because they were cheap and quick to get on desertcart. I quickly fell in love. Though they aren't perfect. Pros: Size. They're tiny. Even 2 years on, most microcontrollers are *at least* 2 to 4 times the size. The small size makes them easy to fit into almost any project. They're literally the size of a postage stamp. I can cover one with my finger. Which brings me to the next pro: I/O. Even at this tiny size, you still have tons of I/O, with support for hardware interrupts, UART, I2C, SPI, and true analog pins with DAC. The big one for me, though, is HID support through the USB type C port. That's a much less common feature than you'd think. If you want to make devices that can talk to other devices as an input device, you need this. Speed. You don't really think that a simple Arduino device needs to be fast, but having a 48mhz processor and 32mb of SRAM to work with open up a LOT of possibilities. Take, for example, my most recent project. I wanted to make a vintage laptop keyboard work with a modern laptop motherboard. But I wanted to do so without damaging the original keyboard. So to interface the two, I needed the Xiao to be able to read the PS/2 protocol that the keyboard was talking in, and give USB HID protocol commands to the computer. Reading the PS/2 protocol takes very precise timing. Your code has to execute within a certain number of microseconds, otherwise the command will fail. Because of the speed of the processor, I could have more code executing in the interrupts while still staying under the threshold. Cons: Storage. While I've never run up against the limit, the Xiao has 256 kB of flash memory. That's not the smallest, but it's certainly not the biggest I've seen on a microcontroller. So I do get a little nervous when I start importing a bunch of libraries. So far, my most involved project, the keyboard that I talked about earlier, only uses about 25% of that storage. And that's importing two different libraries plus my custom code. But if you have a large project that takes many libraries or a whole lot of code, you might run into problems with storage. Bootloader Corruption. I've only had it happen once and it was after hundreds upon hundreds of code uploads. These guys saying they're bricking after 50 uploads have to be doing something wrong. Or maybe it's because they're on Mac hardware, I don't know. But I've had to upload 50 times pretty much everyday I've worked on this project and so far it's not been a problem. But like I said, I did have one of my original three stop responding to USB. So the problem does exist. The device itself still does what the last upload of code told it to do, but I can no longer get it to talk with the Arduino software. And resetting the unit didn't resolve it. So you're mileage may vary.
Review: Awesome tiny microcontroller! - This tiny microcontroller is great for small projects. Actually, it's quite powerful for what it is and has plenty of I/O pins. My son uses it for Star Wars props and Cosplay. It's great for wearables, controlling LEDs, and just about anything an Arduino can do but just more. The setup can be a little confusing at first, but the documentation on the SeedStudio site is really good. It will walk you through with setting up the Arduino IDE or setting up Circuit Python, since the setup is very different from each other. I've programmed this little microcontroller with both the Arduino IDE and with Circuit Python. Circuit Python might be more beginner friendly. I really like that it has USB Type-C connector because then I can use the same cable as my Mobile Phones. It's annoying to have so many different cables around. One thing to make note is that these microcontrollers are not 5v tolerant. Yes, you can power it with 5 volts, but the inputs and outputs are 3.3 volts. The one thing I wish it had was a reset button, but it's so small I'm sure it would be impossible to fit. You can add a reset button because there are soldering pads for it, but it doesn't have one on the board it self. So, if you are making wearables this would be great. Actually, you can use it to control servos, led light strips, and a ton more. It even has a DAC so you can technically make it produce sound too!

## Features

- 🌱【Powerful CPU】 The Seeeduino XIAO is equipped with an ARM Cortex-M0+ 32bit 48MHz microcontroller, which is three times faster than Arduino Uno and Arduino Nano. Furthermore, this Arduino IDE compatible board XIAO has 256KB flash memory and 32KB SRAM.
- 🌱【Rich Interfaces in a Tiny Size】 The device has 14 GPIO pins, each of which has 11 analog channels, 11 digital channels, I2C*1, UART*1, and SPI*1, USB Type-C interface*1 in a tiny space, just 20mm*17.5mm (about the size of your thumb). Seeeduino XIAO is the smallest Arduino compatible board in the Seeeduino series.
- 🌱【Fully compatible with Arduino IDE】 Seeeduino XIAO development board is perfectly compatible with Arduino IDE and you can easily create small projects using the extensive and comprehensive Arduino library. It has a 2.54mm pin pitch and can be used even when inserted into a breadboard because it is an Arduino microcontroller.It has a 2.54mm pin pitch and can be used even when inserted into a breadboard because it is an Arduino microcontroller.
- 🌱【Applications】 Seeeduino XIAO is suitable for Wearable devices, Rapid prototyping, DIY keyboard, USB to multi-channel TTL/USB host mode, etc.
- 🌱【Perfect for Wearable and Tiny Arduino Projects】 This microcontroller has good performance in processing but needs less power. As a matter of fact, it is designed in a tiny size and can be used for Arduino wearable devices and small projects.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B08745JBRP |
| Best Sellers Rank | #283 in Single Board Computers (Computers & Accessories) |
| Brand | seeed studio |
| Color | 3PCS |
| Customer Reviews | 4.4 4.4 out of 5 stars (739) |
| Date First Available | April 15, 2020 |
| Item Weight | 0.317 ounces |
| Item model number | 110010004 |
| Manufacturer | seeed studio |
| Number of Processors | 1 |
| Operating System | Windows, macOS, Linux |
| Package Dimensions | 3.58 x 2.24 x 0.51 inches |
| Processor | 48 MHz none |
| Processor Brand | ARM |
| RAM | SRAM |
| Series | Seeeduino XIAO |
| Wireless Type | 802.11b |

## Product Details

- **Brand:** seeed studio
- **CPU Model:** None
- **Memory Storage Capacity:** 256 KB
- **Model Name:** Seeeduino XIAO
- **Ram Memory Installed Size:** 32 KB

## Images

![XIAO SAMD21 - Image 1](https://m.media-amazon.com/images/I/41ednqv7gXL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ My go to for sooo many reasons
*by R***S on May 10, 2021*

I bought 3 of these a couple years ago to play around with. At the time, it was just because they were cheap and quick to get on Amazon. I quickly fell in love. Though they aren't perfect. Pros: Size. They're tiny. Even 2 years on, most microcontrollers are *at least* 2 to 4 times the size. The small size makes them easy to fit into almost any project. They're literally the size of a postage stamp. I can cover one with my finger. Which brings me to the next pro: I/O. Even at this tiny size, you still have tons of I/O, with support for hardware interrupts, UART, I2C, SPI, and true analog pins with DAC. The big one for me, though, is HID support through the USB type C port. That's a much less common feature than you'd think. If you want to make devices that can talk to other devices as an input device, you need this. Speed. You don't really think that a simple Arduino device needs to be fast, but having a 48mhz processor and 32mb of SRAM to work with open up a LOT of possibilities. Take, for example, my most recent project. I wanted to make a vintage laptop keyboard work with a modern laptop motherboard. But I wanted to do so without damaging the original keyboard. So to interface the two, I needed the Xiao to be able to read the PS/2 protocol that the keyboard was talking in, and give USB HID protocol commands to the computer. Reading the PS/2 protocol takes very precise timing. Your code has to execute within a certain number of microseconds, otherwise the command will fail. Because of the speed of the processor, I could have more code executing in the interrupts while still staying under the threshold. Cons: Storage. While I've never run up against the limit, the Xiao has 256 kB of flash memory. That's not the smallest, but it's certainly not the biggest I've seen on a microcontroller. So I do get a little nervous when I start importing a bunch of libraries. So far, my most involved project, the keyboard that I talked about earlier, only uses about 25% of that storage. And that's importing two different libraries plus my custom code. But if you have a large project that takes many libraries or a whole lot of code, you might run into problems with storage. Bootloader Corruption. I've only had it happen once and it was after hundreds upon hundreds of code uploads. These guys saying they're bricking after 50 uploads have to be doing something wrong. Or maybe it's because they're on Mac hardware, I don't know. But I've had to upload 50 times pretty much everyday I've worked on this project and so far it's not been a problem. But like I said, I did have one of my original three stop responding to USB. So the problem does exist. The device itself still does what the last upload of code told it to do, but I can no longer get it to talk with the Arduino software. And resetting the unit didn't resolve it. So you're mileage may vary.

### ⭐⭐⭐⭐⭐ Awesome tiny microcontroller!
*by J***A on November 13, 2022*

This tiny microcontroller is great for small projects. Actually, it's quite powerful for what it is and has plenty of I/O pins. My son uses it for Star Wars props and Cosplay. It's great for wearables, controlling LEDs, and just about anything an Arduino can do but just more. The setup can be a little confusing at first, but the documentation on the SeedStudio site is really good. It will walk you through with setting up the Arduino IDE or setting up Circuit Python, since the setup is very different from each other. I've programmed this little microcontroller with both the Arduino IDE and with Circuit Python. Circuit Python might be more beginner friendly. I really like that it has USB Type-C connector because then I can use the same cable as my Mobile Phones. It's annoying to have so many different cables around. One thing to make note is that these microcontrollers are not 5v tolerant. Yes, you can power it with 5 volts, but the inputs and outputs are 3.3 volts. The one thing I wish it had was a reset button, but it's so small I'm sure it would be impossible to fit. You can add a reset button because there are soldering pads for it, but it doesn't have one on the board it self. So, if you are making wearables this would be great. Actually, you can use it to control servos, led light strips, and a ton more. It even has a DAC so you can technically make it produce sound too!

### ⭐⭐⭐⭐⭐ Mostly good, but some quirks.
*by A***E on March 13, 2025*

Very good Stamp sized controller. Best in the series, the ESP32S3 chip is one of the best performers. My application involved an I2S interface to a microphone and four RMT interface outputs to SM2812B leds. Issue #1: The 3.3v regulator on this board has fluctuating output and I need to run my microphone on a separate regulator or I can 'hear' the CPU processing as noise in the microphone. Other arduino boards do not have this issue. The oscilloscope revealed that this chip makes it's power rails rather noisy! Issue #2: Pin 7 (GPIO43) has a part on it that makes the bandwidth poor. This pin isn't usable for high bandwidth control. It's a design choice on their part. Darn good board. Five stars.

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*Product available on Desertcart Ireland*
*Store origin: IE*
*Last updated: 2026-03-31*