Spresense e-Violin V3 (under development)

We're developing a new version of Spresense e-violin.
From this version, we try to automatically tune the strings.

As a trial, we attached a single DC motor to pull one string. We also attached piezo pickup, connected to Spresense. The sampled sound is FFTed and the estimated frequency is used to adjust the tension of the string.

In near future, we expect to control four motors by this 3D-printed motor box.

Spresense e-Violin V2


"Spresense e-Violin" is a handmade electric violin controlled by Sony's Spresense. This is a brand new, built-from-scratch version of our previous remodeled e-violin. A new feature is lots of LEDs and the ultraviolet LED control that illuminates the bow hair, dyed with fluorescent liquid.

Making tips:

Previous version:


投稿日: カテゴリー Musicタグ

HEMS Bug

ELEKIT sells a cute toy grasshopper with solar panels. I used a door vibration sensor, a temperature/humidity sensor, acceleration sensor, and human detection sensor. Also I added a song module taken from Eric Carl’s ‘The Very Quiet Cricket’. This one sends the atmosphere information with BLE and controls home appliances with ECHONET Lite. This development was fun.

This was awarded by the first ELEKIT Contest
第1回「エレキット くらしハックコンテスト」技術賞受賞作品

投稿日: カテゴリー Homeタグ

Remodel Zyuoh Changer into a Phone

Doubutsu Sentai Zyuohger (JP HP)”‘s transformation item “Zyuoh Changer” is shaped like a cellphone. Therefore we added a real phone ability by Twilio, Raspberry pi, 3G SIM, and Lightblue Bean. It took as long as 3 months to create this. It was a hard work (After published this article, I realized Qiita is not the place to announce this sort of case study.)

Renesus GR-LYCHEE Customizable Camera Case

GR-LYCHEE is a cute Arduino-compatible ARM Cortex-A RZ/A1LU board with a nice camera module, produce by Renesus. You can get one here. Our model is intended to be the best case of the board when used as a camera, which can contain an easy-to-get dry battery case and an LCD display, as well as a low-cost universal prototyping board sold at Akizuki denshi.On top of the case is the LEGO-compatible attachments, which you can play with.

You can get one at our DMM shop!

With this case, we won the first prize at GR-LYCHEE DESIGN CONTEST 2018.

Bidirectional Picture Story Show

This is an IT-powered picture story show that automatically controls lights, fan, etc. on the progress of the story. The audience can also give feedback to the system by making handclap or any noise.

Demonstrated at :
2018.8.4-5 @ Maker Faire Tokyo 2018
2018.8.14 @ Kuraki Nagata Nursery School