Seeed Studio XIAO Series are diminutive development boards, sharing a similar hardware structure, where the size is literally thumb-sized. The code name "XIAO" here represents its half feature "Tiny", and the other half will be "Puissant".
Seeed Studio XIAO nRF52840 Sense is carrying Bluetooth 5.0 wireless capability and is able to operate with low power consumption. Featuring onboard IMU and PDM, it can be your best tool for embedded Machine Learning projects.
 
Features
Versatile Microcontroller: Incorporate the Nordic nRF52840 chip with FPU, operating up to 64 MHz, mounted multiple development ports, supported by Arduino / CircuitPython
Wireless Capabilities: Implement Bluetooth 5.0, BLE functions with onboard antenna, also provide NFC connectivity
Elaborate Power Design: Provide ultra-low power consumption as 5 μA in deep sleep mode while supporting lithium battery charge management
Advanced onboard Functionality: Assemble additional digital microphone and 6-axis IMU in the tiny board for embedded Machine Learning applications
Thumb-sized Design: 21 x 17.5mm, Seeed Studio XIAO series classic form-factor, suitable for wearable devices
 
Seeed Studio XIAO nRF52840 Sense has an ultra-low power consumption of only 5 μA in the deep sleep mode, the embedded BQ25101 chip supports battery charge management which prolongs its use time. Moreover, Seeed Studio XIAO nRF52840 Sense supports the USB Type-C interface which can supply power and download code. It also has rich On-chip Memory of 1 MB flash and 256 kB RAM, and an Onboard Memory of 2 MB QSPI flash. There are 11 digital i/o that can be used as PWM pins and 6 analog i/o that can be used as ADC pins. It supports UART, IIC, and SPI all three common serial ports. 1 Reset button, 1 3-in-one LED, 1 Charge LED, and 1 Bluetooth antenna are on board, allowing developers to debug their code very easily.
As the advanced yet smaller version of the Seeed Studio XIAO nRF52840, it carries two extra onboard sensors. One of them is a digital microphone created through Pulse Density Modulation(PDM) module on the nRF52840 chip. It can receive audio data in real-time which allows it can be used for audio recognition. The board can receive audio data through the MSM261D3526H1CPM microphone. The other one is 6-axis Inertial Measurement Unit(IMU) which can be applied in TinyML projects like gesture recognition.
The powerful performance makes it perfect for TinyML AIoT projects requiring gesture/voice recognition, and the tiny size allows it to be used in wearable devices and Internet of Things projects, not just for prototypes but the mass production. Furthermore, Seeed Studio XIAO nRF52840 Sense is friendly to the communities for its strong software compatibilities, which supports Arduino, Micropython, and CircuitPython. Except for the software, flexible I/O allows it to speak to almost any external device.

SpecificationItemSeeed Studio XIAO nRF52840Seeed Studio XIAO nRF52840 SenseProcessorNordic nRF52840The same as Seeed Studio XIAO nRF52840ARM® Cortex®-M4 with FPU runs up to 64 MHzWirelessBluetooth 5.0/NFCThe same as Seeed Studio XIAO nRF52840On-chip Memory1 MB flash and 256 kB RAMThe same as Seeed Studio XIAO nRF52840Onboard Memory2 MB QSPI flashThe same as Seeed Studio XIAO nRF52840Interface1xUART, 1xIIC, 1xSPI, 1xNFC, 1xSWD,The same as Seeed Studio XIAO nRF5284011xGPIO(PWM), 6xADCSensors -Onboard PDM digital microphoneOnboard 6-axis IMUDimensions21 x 17.5mmThe same as Seeed Studio XIAO nRF52840PowerCircuit operating voltage: 3.3V@200mAThe same as Seeed Studio XIAO nRF52840Charging current: 50mA/100mAInput voltage (VIN): 5VStandby power consumption: <5μAApplicationSmall and flexible wearable deviceWifi/Bluetooth controlled wireless connection projectEmbedded Machine Learning ProjectIoT and TinyML AI applicationsGreat for mini Arduino projectsHardware Pinout