Xiao nRF52840 developer module

Another module from the SeeedStudio XIAO series now available in our offer. This time it’s based on the nRF52840 from Nordic Semiconductors. This chip is designed for use in IoT devices operating on Bluetooth 5.0 networks (the module comes with a built-in antenna). In addition to BLE 5.0, it also supports Bluetooth Mesh, Thread, Zigbee, and 802.15.4.

As usual with the XIAO series, the dimensions are compact — 21 x 17.8 mm. This module also includes a LiPo battery charging circuit and a USB-C connector.

The processor itself is an ARM® Cortex®-M4 with FPU, capable of running at a maximum clock speed of 64 MHz. The FPU (Floating Point Unit) means that floating-point operations are hardware-accelerated, so advanced calculations required for many algorithms will not be a bottleneck.

The processor has 256 kB of RAM and 1 MB of built-in flash memory. Additionally, the module includes a second 2 MB flash memory connected via QSPI (Quad SPI), offering high throughput.

The module features a reset button and a user-programmable LED (capable of displaying three colors) as well as a charging status indicator LED. In sleep mode, the module consumes 5 µA while maintaining battery charging capabilities.

All good, but how do I program it?

As IoT modules become more complex and powerful, their programming also becomes a bit more involved. More capabilities mean more choices — and thus more decisions to make.

In the case of the nRF52840, there are two beginner-friendly programming options. The first is using microPython. The second is Arduino IDE. Depending on your project goals, you have two options here:

If your project focuses primarily on Bluetooth Low Energy, you should use the Seeed nRF52 Board library. If embedded ML or TinyML are more important for your project, then go with the Seeed nRF52 mbed-enabled Boards. More details can be found on the SeeedStudio Wiki.

The module offers the following interfaces: 1 x UART, 1 x IIC, 1 x SPI, 1 x NFC, 1 x SWD, 11 x GPIO (PWM), 6 x ADC.

IMPORTANT All pins operate at 3.3V logic levels. Supplying a higher voltage to a pin will damage the module.

Like almost all modules in the XIAO series, it is designed for surface mounting — the bottom of the PCB has no components and uses castellated connectors.

• Size: 21 x 17.8 mm
• Processor: nRF52840, 1 MB + 2 MB flash, 256 kB RAM, 64 MHz
• Interfaces: 1 x UART, 1 x IIC, 1 x SPI, 1 x NFC, 1 x SWD, 11 x GPIO (PWM), 6 x ADC
• Power supply voltages:
  • via USB: 5V
  • via BAT pads on the bottom of the board — max 4.2V