But how to you test whether such a board is capable of the harsh conditions?
Vibration and shock testing verifies that Spresense can withstand a rocket launch. The Spresense main board was subjected to low and high-frequency tests as well as shock tests at different frequencies. In the low-frequency transient test at 5-100Hz, the board experienced forces of up to 20G. The high-frequency tests involved a range of frequencies from 10 – 2kHz in a power spectrum density range of 0.1 – 2.0 G2/Hz, with forces equivalent to between 82 and 336G.
The three shock tests measured, respectively at: 500 Hz with typically, 100 GSRS (Shock Response Spectrum of Gravity), 500 – 2.4kHz at 5.32 dB/oct. and lastly, 2.4 – 4kHz with typically, a mindboggling 1,000 GSRS!
The thermal vacuum tests were over temperature range -20C – 60C cycled at +/- 2C per minute, at a pressure of 1.33 mPa. The Spresense board showed no appearance damage or malfunction during or after the tests.
In the proton irradiation tests, the Spresense board was subjected to proton bombardment (as though from a particle accelerator) at energies ranging between 10 and 70MeV, for durations of between 95 and 166 minutes, at fluxes of up to 1.742 x 107 p/cm2/s. That is a lot of protons. The results showed no significant ill effects other than requiring power-on resets, but mean that the board needs an aluminum shield to protect from radiation in a sun-synchronous orbit of 500km above the Earth.
It’ll be exciting to see how this CircuitPython compatible board will do!
Spresense on the Moon
Sony is also contributing to another JAXA mission in 2022, one that will take a transformable robot to the moon. The mission is to gather information about the lunar surface with an innovative project to acquire data using a transformable robot. The mission is very much part of the New Space movement, making use of COTS equipment. Sony’s contribution is the control system for the robot that uses Spresense as a core component. Again, the compact size of Spresense and very low power consumption are required, but it is the ability of Spresense to work with robotics that was the key.
Transformable lunar robot (left: before transformation, right: after transformation)
It is hoped that being able to demonstrate the capabilities of Spresense in space will contribute greatly to solving problems back here on Earth.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.