Seeed Studio XIAO SAMD21 - Ultra-Small ARM Cortex-M0+ Development Board
Microcontroller and Dev Modules
₹700
The Seeed Studio XIAO SAMD21 is a thumb-sized, highly capable development board powered by the Atmel ATSAMD21G18 ARM Cortex-M0+ processor. Measuring just 21 x 17.5mm, it is the perfect core for wearable devices, mini robotics, and space-constrained IoT projects. Key Features: Tiny Footprint: As small as a thumb, designed specifically for wearables and compact PCB integration. Powerful Core: 32-bit ARM Cortex-M0+ running at 48MHz with 256KB Flash and 32KB SRAM. Modern Interface: Features a reliable USB Type-C connector for power and programming. Rich I/O: 11 digital/analog pins, 10 PWM pins, 1 DAC output, along with I2C, UART, and SPI interfaces.
Overview
The Seeed Studio XIAO SAMD21 (formerly Seeeduino XIAO) is the smallest member of the Arduino-compatible microcontroller family. Despite its incredibly small footprint, it packs the processing power of a 32-bit ARM Cortex-M0+ microcontroller. This makes it significantly more powerful than traditional 8-bit boards like the Arduino Nano, while occupying a fraction of the space.
Whether you are building a custom macro pad, a smart wearable device, or a miniature sensor node for your next robotic build, the XIAO SAMD21 provides the perfect balance of size, power, and ease of use.
Technical Specifications
| Feature | Specification |
|---|---|
| Microcontroller | Atmel ATSAMD21G18 |
| Processor | ARM® Cortex®-M0+ 32-bit @ 48MHz |
| Memory | 256KB Flash, 32KB SRAM |
| Operating Voltage | 3.3V (5V tolerant on VIN pin only via internal regulator) |
| Digital I/O Pins | 11 |
| Analog Input Pins | 11 |
| DAC Output | 1 (True analog output on A0) |
| PWM Pins | 10 |
| Interfaces | 1x I2C, 1x UART, 1x SPI |
| Connector | USB Type-C |
| Dimensions | 21 x 17.5 x 3.5 mm |
Pinout and Interfaces
The XIAO SAMD21 is designed to be breadboard-friendly, with castellated holes that also allow it to be soldered directly onto a custom printed circuit board as a module.
- True Analog Output: Unlike standard Arduino boards that only offer PWM, Pin A0 provides a true Digital-to-Analog Converter (DAC) output, perfect for audio generation.
- Touch Interfaces: Several pins natively support Q-touch functions, making it easy to create capacitive touch buttons for interactive displays.
- Power Pads: The back of the board features dedicated pads for connecting a battery directly to the circuit.
⚠️ Important Voltage Warning: The logic level of the XIAO SAMD21 is 3.3V. Applying 5V to any of the standard GPIO pins will permanently damage the microcontroller. Always use logic level converters when interfacing with 5V sensors.
Software Compatibility
The board is fully open-source and flexible. It can be programmed using:
- Arduino IDE (Simply install the Seeed SAMD Boards package)
- CircuitPython
- MicroPython
