Articles

I recently replaced the RFID ring reader that I use to unlock my front door with an IoT fingerprint reader. An obvious advantage is that I risk losing my finger way less than a ring.

A simple framework using Three.js and MQTT to easily create digital twins

Earlier this year, a friend of mine was organizing an event to promote eco-friendly behaviors. She wanted someone to talk about our relationship with energy and asked me to give a presentation on the topic, which I agreed to. I wanted the presentation to be entertaining so I designed a set of hardware demonstrations aimed at explaining physical concepts related to energy.

測定データをクラウドに上げ体重の推移を管理できるIoT体重計

One of the companies I used to work for had a serious bathroom issue: My floor had only three toilet stalls for about 200 employees. There were countless times when I would walk all the way to the bathroom only to find all stalls occupied. I built this simple system to quickly identify whether one or more stall were. It consists of an IoT sensor installed on the bathroom stalls' door and an indicator placed somewhere easily visible.

This is an IoT ceiling light controller which includes an HC-SR501 PIR motion sensor. It is built around a Wemos D1 mini (ESP8266 breakout board), which controls a homemade TRIAC breakout board. TRIACs provide the advantage of switching devices on and off silently, as opposed to a mechanical relay.

This project consists of an HC-SR501 PIR motion sensor and a DHT22 temperature and humidity sensor connected to a Wemos D1 mini, an ESP8266 breakout board.

I wanted my home automation system to detect when I arrive home so as to unlock my door automatically or let me know if I leave the apartment without turning the A/C off. I figured my smartphone could be used to achieve this since it is equipped with a vast array of sensors and connectivity options. For example, I could use an app like OwnTracks which would send an MQTT message once I enter a certain perimeter around my apartment. However, constantly monitoring one's GPS location is wasteful in terms of battery life. Another option would be to ping my phone's IP address to check if it is connected to the WiFi, but smartphones can sometimes take a while to connect. So, I decided to use BLE advertising, which does not use too much battery while still remaining constantly active.