Articles
Wireless motion sensor
This is a wireless motion sensor that runs on rechargeable batteries. It can be deployed anywhere and sends a signal using an NRF24L01 wirless module whenever it detects motion.
WiFi light bulb controller
Wifi controlled smart light bulbs can now be purchased from less than USD 10. However, those can often only be used by a specific application provided by the vendor and can involve exchanging data with a third party server. I wanted a solution to use my own software while benefiting from the cheap hardware so I replaced the wifi module of a a cheap Wifi light bulb my own electronics.
Weight tracker
Managing one's body weight can be quite a challenge. And as the quote from Peter Drucker goes, "You can't manage what you can't measure". So, I built a body weight scale that can upload data to an API of my choice, which was the object of this article.
Web based approval system
With the COVID-19 and the introduction of remote work, a many Japanese companies were struggling with the approval of documents, since those needed to be physically stamped with one's personal seal named Hanko.
I decided to solve this issue by creating a web application to keep track of approvals
Vocabulary practice web app
When learning a new language, there is no way around having to learn its vocabulary. This simple web app was made to help with this process by providing a multiple choice question style UI. It was designed mainly for Japanese, which uses Chinese characters that can have multiple readings.
Vanilla javascript neural network
This simple web app written in JavaScript which trains a neural network on data provided as .csv file. The neural network is a fully connected network implemented from scratch and the structure of its hidden layers can be set by the user. The dimension of its inputs and outputs is automatically adjusted to fit the provided training data.
User management microservice based on Neo4J
Web applications commonly require a user database and the management logic for it. Having to build such software infrastructure for each individual app would be time consuming so I designed a general-purpose user management microservice that can be easily integrated in a project.
User management and authentication service using MongoDB

More often than not, web applications require restrictions regarding who can access the content that they serve. This involves an user management and authentication system, which, if designed inappropriately, can lead to security concerns. However, the development of such system can be time consuming, especially if done repeatedly for multiple applications.
This very application, a CMS based on Neo4J
Publishing articles on a website can be as simple as uploading HTML files to a web server. However, writing articles in raw HTML can be time consuming. A content management system (CMS) is an application designed to solve this issue by providing a simple way to create and manage web content directly from the web browser. There are many CMSs available, namely Wordpress or Joomla but I decided to create my own as a form of practice and in order to have it highly customized to my needs.
Solar power setup
I got my hands on a 600W 12V inverter so I decided to experiment with generating my own electricity.