Under the microscope: the Sony Spresense development board

Under the microscope: the Sony Spresense development board

Prototyping for IoT applications can be a lengthy involved process. Developers are coming up with ever new ways to increase efficiency, and in the meantime, manufacturers are doing their part too.

The Spresense is a compact development board based on Sony’s power-efficient multicore microcontroller CXD5602. Featuring an integrated GPS, high-res audio output and multi mic inputs, the board is a low-power microprocessor solution for mobile applications, allowing developers to create IoT applications within a shorter timeframe.

The range gives developers the ability to build solutions using the Arduino IDE software or the NuttX operating systems. Depending on specific projects, the board can be equipped with optional add-ons and Arduino shields, making the Spresense versatile enough to be used in IoT applications including imaging, logistics, AI, robotics, audio, security, production and more areas where battery life and CPU power are key.

Sony’s Spresense range removes the effort of developing high quality IoT solutions. With such vast application capabilities, and the versatility to be used across a range of industries and professions, we have strategically partnered with Distrelec Group to ensure the range can be easily accessed by the broader customer network.

Adam Hurst, Director of Primo Components, Sony’s European distribution partner

What is particularly appealing about the Sony Spresense range is its versatility and application capabilities. The range is suitable for such a wide range of use cases ranging from robotics and tracking, through to AI and image recognition, allowing solutions for the wider Distrelec community.

Steve Herd, CEO at Distrelec

With the many features and advantages the Sony Spresense range provides, we’re taking a deep dive into the specifications of the main board, extension board and camera board and will provide some pointers on how to start developing with these latest innovations by Sony.

Hardware: main board

The Spresense main board has the following specifications:

Model name	CXD5602PWBMAIN1
Size	50.0 mm x 20.6 mm
CPU	ARM® Cortex®-M4F x 6 cores
Maximum clock frequency	156 MHz
SRAM	1.5 MB
Flash memory	8 MB
Digital input / output	GPIO, SPI, I2C, UART, I2S
Analog input	2 ch (0.7 V range)
GNSS	GPS(L1-C/A), QZSS(L1-C/A), GLONASS(L1), WAAS, QZSS(L1-S)
Camera input	Dedicated parallel interface
Operating conditions	Temperature: 10 – 40℃, Humidity: 30% – 80% (no condensation)
Storage conditions	Temperature: -20 – 60℃, Humidity: 10% – 80%

The names and locations of connectors, LEDs and switches on the main board are shown below.

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.
[CN2]	Micro USB Type-B connector.
[CN4]	B-2-B 100-pin connector to interface to additional boards. This connector is on the underside.
[CN5]	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:

A PDF file of the main board circuit diagram can be obtained here.

Hardware: extension board

The Spresense extension board has the following specifications:

Model name	CXD5602PWBEXT1
Size	68.6 mm x 53.3 mm
Audio input / output	4 ch analog microphone input or 8 ch digital microphone input, headphone output
Digital input / output	3.3 V or 5 V digital I/O
Analog input	6 ch (5.0 V range)
External memory interface	microSD card slot
Operating conditions	Temperature: 10 – 40℃, Humidity: 30% – 80% (no condensation)
Storage conditions	Temperature: -20 – 60℃, Humidity: 10% – 80%

The names and locations of connectors, LEDs and switches on the main board are shown below.

Name	Description
CN3	B-2-B connector 100 pins connector for the main board.
CN4	Micro SD card.
CN6	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.
CN7	Headphone 3-pole 3.5mm jack.
JP1	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 microphones.
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.
JP14	Jumpers to support digital microphones on JP10.

The following block diagram shows the extension board design.

A PDF file of the extension board circuit diagram can be obtained here.

Hardware: camera board

The Spresense camera board has the following specifications:

Model name	CXD5602PWBCAM1
Size	24.0 mm x 25.0 mm
Number of effective pixels	2608 (H) x 1960 (V) = approx. 5.11 M pixels
Operation voltage	DC 3.7 V
I/O voltage	DC 1.8 V
Camera interface	CMOS 8 bit parallel
Output format	Y/C, RGB, RAW and JPEG
Control interface	I2C
Built-in filter	IR cut filter
FOV	78° ± 3°
Depth of field	77.5 cm～ ∞
F value	2.0 ± 5%
Focus	Fixed focus
Operating conditions	Temperature: 10 – 40℃, Humidity: 30% – 80% (no condensation)
Storage conditions	Temperature: -20 – 60℃, Humidity: 10% – 80%

On top of that, you can also find the board’s image sensor specifications below:

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
Photometry	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)

In addition, the following table covers the specifications of the lens:

Function	Spec
Lens type	1/4 inch 4 pieces
Effective Focal Length	2.74mm
F-number	2.0±5%
Field of view	78°±3°
Chief ray angle	<33.5°
Distortion	<1.5%
Image quality	Center 1100 lines, Near the corners 900 lines
Focus distance	1.5m
Focusing range	77.5 to 237.06cm

A PDF file of the camera board circuit diagram can be obtained here.

How to start developing

Off the basis of these technical specs, you can determine the best way to use the Spresense boards for your purposes. They open up a wide variety of applications and are, as mentioned, particularly suitable for IoT uses. When it comes to getting going with the Spresense range, there are a huge range of resources available to guide you.

As a flexible solution, the boards offer the possibility to develop using Arduino IDE, a programming environment most developers will be familiar with, or Sony’s own Spresense SDK, which offers extended possibilities for pros.

Going beyond even this, you can find guidance on the specifics of working with the Spresense in the many tutorials provided by Sony. We recommend the “learning by doing” approach, so once you’ve got your hands on the Spresense range, following along one of these tutorials is the perfect way to get started.

After that, the sky’s the limit – many developers have already shared exciting projects using the Sony Spresense, and you can find inspiration by browsing through them below.

Now all that’s left to do is start developing your very own project to be added to the hub – we can’t wait to see what you’ll come up with!

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