Spresense Header CodeSpresense Header Code

Edge computing with low power consumption

The Spresense development board enables edge solutions with high computing ability and low power consumption.

Spresense Hardware

1. Spresense Board

This section describes the Spresense hardware.

Spresense consists of two boards:

It is also possible to design your own

The main board uses a processor developed by Sony for IoT and sensing applications. The main board can be operated alone or with the extension board.

The Spresense uses Sony’s new chipset on the main board:

  • The CXD5602 System on Chip (SoC) multi core processor with GNSS

  • The CXD5247 power management and audio analog interface chip

The Spresense extension board is a board which extends the interfaces compared to the Spresense main board. The Spresense main board and the Spresense extension board are connected by a Board-to-Board (B-2-B) connector. The Spresense extension board has Arduino Uno pin compatible shape and pin socket locations. However, there are some differences compared to the Arduino Uno. For details, please refer the Differences between Spresense and Arduino Uno.

overview hardware both
Figure 1. Extension board at the bottom and the main board mounted on top.

1.1. Main board

The Spresense main board has the following features.

  • Sony’s CXD5602 Processor

  • 8 MB Flash memory

  • PCB with small footprint

  • Dedicated camera connector

  • GNSS (GPS) antenna

  • Pins and LEDs

    • Multiple GPIO (UART, SPI, I2C, I2S)

    • 2 ADC channels

    • Application LED x 4 (Green)

    • Power LED (Blue)

    • USB serial port

All Spresense main board pins operate at 1.8V. Connecting the main board pins to higher voltage can cause permanent damage.

overview hardware mainboard signal
Figure 2. Spresense main board.

The name and location of connectors, LEDs and switches on the main board are shown below.

Table 1. Connectors, switches and LEDs.
Name Description

[PWR] Power LED

Power LED. Emits blue light when power is supplied.

[RST] Reset button

Reset button.

[LED0] to [LED3]

Four user controllable green LEDs.


Micro USB Type-B connector.


B-2-B 100-pin connector to interface to additional boards. This connector is on the underside.


Camera connector.

[BR] Boot recovery button

This is used when restoring to the factory reset state. Only for recovery, normally not needed.

The following schematic block diagram shows the main board design:

block diagram mainboard
Figure 3. Spresense main board block diagram

PDF file of the main board circuit diagram can be obtained from the following link. Circuit diagram of Spresense main board

1.2. Extension board

The Spresense extension board has the following connectors in addition to Arduino Uno compatible pin sockets.

  • 3.5 mm headphone jack

  • Micro SD card

  • An extra USB port

  • Multiple microphone pins

overview hardware extboard signal
Figure 4. Spresense extension board

The extension boards configuration is set by jumpers.

Table 2. Extension Board Connectors and Jumpers
Name Description


B-2-B connector 100 pins connector for the main board.


Micro SD card.


Micro USB Type-B connector. It can provide USB MSC (Mass Storage Class) function allowing access to the SD card on the extension board directly from the PC.


Headphone 3-pole 3.5mm jack.


GPIO voltage can be set to 5V or 3.3V by using a jumper on JP1. A standard 2.54mm pitch jumper should be used. This one will be supplied with the extension board.

JP10 - pins 3 to 16

Microphone connector. These pins connect analog or digital microphone. Please refer How to use microphones for details.

JP10 - pins 1 and 2

You can disable UART2 on the extension board by closing pin 1 and 2 on JP10. This allows UART2 on the main board to be used at 1.8V I/O. No jumper is shipped with the extension board, a 2.54 mm pitch jumper should be used.


Jumpers to support digital microphones on JP10. Please refer How to use microphones for details.

The micro SD card that can be used with the Spresense extension board must be formatted in FAT32.

The only "SDHC" micro SD card is formatted with FAT32 at the time of shipment from the manufacturer.

For cards formatted with other file systems, format them in FAT32 using a formatting tool for SD cards in a PC etc. beforehand.

The following block diagram shows the extension board design.

block diagram extboard
Figure 5. Spresense extension board block diagram.

PDF file of the extension board circuit diagram can be obtained from the following link: schematics of Spresense extension board.

1.3. Spresense camera board

The Spresense camera board has the Sony ISX012 image sensor mounted together with a lens. The Sony ISX012 has an effective pixel count of 5.11M pixels and an onboard encoder that can acquire pictures in JPEG, RAW, Y/C or RGB format.

HW camera board
Figure 6. Spresense camera board with the ISX012 camera module.
Table 3. Sony ISX012 image sensor specification:
Image sensor

Sensor type

1/4 type CMOS image sensor

Effective pixel

5.11M pixels

Recording pixel

5.04M pixels

Camera control

ISO sensitivity

ISO 40~800

Scene selection

12 preset

Exposure control mode

Auto, Shutter priority, ISO sensitivity priority, Long time AE


Multi pattern, Center weight, Average, Spot

Exposure compensation

±2EV, 1/3 EV steps

Shutter speed range

1/8 s (long AE mode) to 1/42000 s

White balance

Auto, Daylight, Cloud, Fluorescent, Lamp

Focus control

Auto, Single AF, Continuous AF, Manual control

Picture format

Output still picture format

JPEG(4:2:2), Y/Cb/Cr, YUV, RGB, RAW, JPEG+YUV(thumbnail)

Still data rate

5M pixel 15 frame/s JPEG output

Movie data rate

SVGA 30 frame/s YCbCr output

HD movie support

1080p(1920×1030 30 frame/s), 720p(1208×720 60 frame/s)
JPEG output, JPEG+YCbCr output

In addition, the following table is the specification of the lens.

Table 4. Camera module lens specification
Function Spec

Lens type

1/4 inch 4 pieces

Effective Focal Length




Field of view


Chief ray angle




Image quality

Center 1100 lines, Near the corners 900 lines

Focus distance


Focusing range

77.5 to 237.06cm

PDF file of the camera board circuit diagram can be obtained from the following link: Circuit diagram of Spresense camera board

2. Custom Board

The B-2-B connector can be used to interface to your own custom board, rather than the Extension board.

For details of mechanical and power supply requirements see the add on board design guidelines

For details of the B-2-B connector pinout and functions see the Circuit diagram of Spresense main board

Your custom board may replicate some of the features from the Extension board which you can copy from the schematics of Spresense extension board.

3. How to use Spresense board

3.1. How to fit a shading seal on the main board

A shading seal is provided with the kit and should be mounted on IC4 in Spresense main board before it is used. The location of where to fit the seal is shown in the picture.

Malfunction might occur if the board is placed under direct or in the proximity of a strong light source, e.g. sunlight or a bright lamp if no shading seal is mounted.
HW shading seal E
Figure 7. Shading seal position.
shading seal picture
Figure 8. Shading seal.
Table 5. The recommended shading seal if you lose the provided one:
Vendor Model



3.2. How to attach the Spresense extension board and the Spresense main board

This section explains how to install the Spresense extension board and the Spresense main board. The package of the Spresense board has 4 spacers to attach the Spresense main board.

overview spacer
Figure 9. Spresense spacers.

These spacers are put in to the through-holes on the Spresense extension board. Please note the positions of the through-holes.

overview spacer through hole
Figure 10. The positions of the through-holes for the spacers.

After putting in the spacers on the Spresense extension board, attach the Spresense main board.

overview spacer connection
Figure 11. Exploded view of the Spresense extension board, spacers and the Spresense main board.
overview spacer direction
Figure 12. The direction of the Spresense extension board and the Spresense main board.

The USB connectors face the same direction. On this picture the Spresense main board and the Spresense extension board have been mounted.

overview spacer finish
Figure 13. The Spresense main board attached to the Spresense extension board.

Please confirm the mating of the B-2-B connector by pressing the Spresense main board and Spresense expansion board from the top and bottom again after completing the installation etc. Please note that the function on the Spresense expansion board such as the micro SD card and the audio function may not work if the mating is incomplete.

Do not separate the Spresense main board from the extension board by force once mounted.

3.3. How to connect and prepare the Spresense main board and Spresense camera board

This section explains how to attach the Spresense camera board to the Spresense main board.

Since the camera module is very sensitive to static electricity it is advised to discharge any static electricity from the body before handling the camera module. This can be done by touching a grounded part, like a grounded computer chassis. Static electricity can cause the camera module to malfunction.

The camera module is connected to the main board (CN5) via a flat cable. The picture below shows how the flat cable is supposed to be mounted. The flat cable can only be inserted in one way to work so it is important to take note on which side it should be connected on.

HW camera setting en
Figure 14. How to connect the Spresense camera board.

The lens of this camera is covered with a small translucent blue plastic film. This is for protection, please remove it before use. Please be gentle when removing the protecting plastic film.

3.4. About the flat cable on the Spresense camera board side

The flat cable connector on both the camera board and main board is rather fragile it is advised not to insert/remove the cable more than necessary.

Please follow the instructions below when inserting/removing the flat cable.

  • When pulling out the flat cable:

    • A. Apply a uniform force to both sides of the lever of the connector, slide the lever slowly and horizontally and pull it out horizontally.

    • B. Pull out the flat cable.

  • When inserting the flat cable

    • C. Insert the flat cable firmly into the connector. The electrode side of the flat cable should be facing away from the PCB. See image below.

    • D. Apply a uniform force to both sides of the lever of the connector and slide the lever slowly horizontally and push it in parallel with the board.

HW FFC camera side en
Figure 15. How to insert or remove a flat cable on the Spresense camera board side.
Please operate the lever of the connector of the camera board slowly and carefully. If you apply uneven force to sides of the lever or move it in an other than horizontal direction with respect to the board you might damage the lever.

Also, the flat cable that can be used as a substitute when the flat cable for the camera is damaged is shown below. Below is list of replacement flat cables, it is advised to use a flat cable as short as possible.

Table 6. Alternative flat cable list:
Vendor Model Length







Wurth Electronics



3.5. Powering the Spresense Board

There are several ways to power the Spresense boards:

spresense musb connect
Figure 16. Spresense main board USB connector
  • Use the main board’s micro USB connector. Simply connect your PC to the micro USB connector on the main board to get started. It will power the main board alone, or the main board and extension board as a set. This is the preferred method for most development. The main board USB is intended for serial port applications only.

  • Connect a 5V±0.25V power source to the VOUT pin on the extension board.

  • If you are using the Spresense extension board the micro USB connector on the extension board can be used to power the system when the two boards are being used as a set.

The Spresense can be powered by a USB battery pack. Some USB battery packs require a minimum load current and Spresense may take less than this current, which will cause the USB battery pack to turn off after a few seconds. For reliable USB battery pack operation choose a battery pack that has an "always on" feature or use a USB "keep-alive load".

The above power supply can be performed simultaneously from plural. Also, when supplying power via the micro USB connector, please use micro USB cable that is as thick and short as possible.