Seeed Studio XIAO Expansion board


A powerful functional expansion board for Seeed Studio XIAO series of only half Raspberry Pi 4 size. It enables build prototype and project in easy and quick way. With its rich peripherals including OLED, RTC, expandable memory, passive buzzer, RESET/User button, 5V servo connector, multiple data interfaces… you could explore infinite possibilities of Seeed Studio XIAO series. Circuit python is also well supported by this board. 




Since more and more Seeed Studio XIAO series have been launched, we have realized the product names of the XIAO series might not be consistent enough. Hence, as the time of new Seeed Studio XIAO product coming out, we have changed all Seeed Studio XIAO series product name. For further information, please refer to here.

Key Features

  • Quick Prototyping: Easy debug and Reset with RESET button and SWD pin led out to the male header. 0.96” OLED, enables visual data to display without PC serial monitor.
  • Rich peripherals: OLED display, RTC, expandable memory space, passive buzzer, user button, on board battery management chip… One board on hand to explore infinite possibilities of Seeed Studio XIAO series.   
  • No Soldering Needed: All pin led out. Convenient plug and play Grove connectors support multiple data protocols, including IIC, Uart, Analog/Digital.
  • Circuit Python Supported: Well supports circuit python. Mini SD card slot enables memory space expand, making it possible to allocate more libraries needed in prototyping and project building.
  • Mini Size: Compact and elegant with only half Raspberry Pi 4 size, perfect for tiny and wearable projects.


Seeed Studio XIAO Expansion Board is a powerful functional expansion board for Seeed Studio XIAO series of only half Raspberry Pi 4 size. It enables build prototype and project in an easy and quick way. With its rich peripherals, you could explore infinite possibilities of Seeed Studio XIAO series. Circuit python is also well supported by this board.

Hardware Overview

Many users adore Seeed Studio XIAO series because of its mini size and elegant design, so we try our best to keep the size as mini as we could when persuing the powerful function and rich interfaces. As you could see, the board is of only half Raspberry Pi 4 size.

Rich peripherals on board including:

  • OLED display: Visual data display without connecting to PC, which enables debug in a more efficient way, and builds application such as a sensor hub, data monitor system, .etc

  • RESET button: No more jumper wire and short circuit, easy reset with just one click. 

  • SWD debug: SWD pin led out as male pin header, making debugger connection and firmware download much easier.

  • High precision RTC: High precision real-time clock with battery backup, enable maintain accurate time when the main power is turned off.

  • Expandable memory: With a MicroSD card slot on the back, no worry about the memory limit any more when adding libraries and using circuit python.

  • User button: Besides the RESET button, also provide another user-defined button.

  • Passive buzzer: Same passive buzzer on Wio Terminal, with which you could change the PMW frequency to award different beep sound to get a "buzzer music".

  • Grove connectors: All pin led out, plug and play grove connectors support common data protocols (Grove IIC2, Grove UART1, A0/D0 Grove*1)

  • Lipo Battery Charging: JST2.0mm standard lipo battery connector and battery management system, supports both USB and lipo battery power supply, and easy onboard battery recharge.

  • 5V servo connector: 5V output led out to male header for 5V servo and sensor connection.

Though with all these rich peripherals, you may find Seeed Studio XIAO Expansion Board also has very high cost performance as Seeed Studio XIAO does.

Seeed Studio SAMD21 XIAO has become one of the hottest products in the Seeeduino series since its release. You may adore its small size and elegant design, powerful CPU powered by SAMD21, or rich interfaces of GPIOs, but no matter what reason makes Seeed Studio XIAO attract to you, now you have one more reason now - Seeed Studio XIAO Expansion Board, which will definitely help you to explore infinite possibilities with Seeed Studio XIAO Series.

Seeed Studio XIAO expansion board supports Seeed Studio XIAO SAMD21, Seeed Studio XIAO RP2040, Seeed Studio XIAO nRF52840, Seeed Studio XIAO nRF52840 Sense. 


  • SWD debug
  • Rapid prototyping
  • Data display
  • Mini Size Project


More Accessories are on the way

Acrylic Case for Seeed Studio XIAO Expansion Board 


Power Supply 5v / 3.7V Lithium Battery
RTC chip PCF8563T/5
RTC battery CR1220
Expandable memory MicroSD Card
Screen 0.96 OLED display
Other External Equipment Passive buzzer, user button, 5Vservo connector
charging current Max: 460mA
Grove Interface Grove I2C *2, Grove UART *1, A0/D0 Grove *1


Part List

Seeeduino XIAO expansion boardX 1


Seeed Studio XIAO products and battery is not included in this product, please click here if you need to get a Seeed Studio XIAO SAMD21.


HSCODE 8543909000
USHSCODE 8543908885




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  1. Product Quality
    from order view
    Makes it easy to test and develop.
  2. Product Quality
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  3. Product Quality
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    Great features, quality build.
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  5. Documentation
    Product Quality
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    I will use the expansion board to be faster with the prototype development and to have less wiring.


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