CXD56 (Spresense)

This directory contains the port of CircuitPython to Spresense. It is a compact development board based on Sony’s power-efficient multicore microcontroller CXD5602.

Board features:

  • Integrated GPS

    • The embedded GNSS with support for GPS, QZSS and GLONASS enables applications where tracking is required.

  • Hi-res audio output and multi mic inputs

    • Advanced 192kHz/24 bit audio codec and amplifier for audio output, and support for up to 8 mic input channels.

  • Multicore microcontroller

    • Spresense is powered by Sony’s CXD5602 microcontroller (ARM® Cortex®-M4F × 6 cores), with a clock speed of 156 MHz.

Currently, Spresense port does not support Audio and Multicore.

Refer to for further information about this board.



Add user to dialout group:

$ sudo usermod -a -G dialout <user-name>


Download and install USB serial driver


Download and install USB serial driver

Build instructions

Pull all submodules into your clone:

$ git submodule update --init --recursive

Build the MicroPython cross-compiler:

$ make -C mpy-cross

Change directory to cxd56:

$ cd ports/cxd56

To build circuitpython image run:

$ make BOARD=spresense

USB connection

Connect the Spresense main board to the PC via the USB cable.

Flash the bootloader

The correct bootloader is required for the Spresense board to function.

Bootloader information:

  • The bootloader has to be flashed the very first time the board is used.

  • You have to accept the End User License Agreement to be able to download and use the Spresense bootloader binary.

Download the spresense binaries zip archive from: Spresense firmware v3-0-0

Extract spresense binaries in your PC to ports/spresense/spresense-exported-sdk/firmware/

To flash the bootloader run the command:

$ make BOARD=spresense flash-bootloader

Flash the circuitpython image

To flash the firmware run the command:

$ make BOARD=spresense flash

Accessing the board

Connect the Spresense extension board to the PC via the USB cable.

Once built and deployed, access the CircuitPython REPL (the Python prompt) via USB. You can run:

$ screen /dev/ttyACM0 115200