goroot Blog

Cloud. Architecture. IoT.

Presence detection: Bee in a box

The ‘bee in a box’ algorithm enables you to detect presence in a given area of your smart home. It will enable your smart home system to know whether in a given area anybody is present or not. No special sensors or other additional hardware is required to do so. Bee in a box algorithm: The theory Imagine somebody handing you over a small box made out of cardboard. On the top side of the box, there is a yellow warning symbol ‘Warning: there might be a bee inside’. Continue reading

ESP32 as BLE Gateway for Xiaomi Mijia BLE Temperature & Humidity Sensor

Problem statement Too many unused BLE sensors, too much time during the COVID-19 lockdown - lets add more sensors! Just because we can… No seriously. I struggled a lot with too much humidity in the air in several areas of my house. After having a hot shower in the bathroom, the humidity condensed at the window, increasing the risk for mold growth. In the basement where our food supplies are stored, we had issues with salt getting wet. Continue reading

Monitor the pH of your reef tank with Tasmota

Monitoring water values of your fish tank is essential. To keep your reef-ecosystem alive, several dozens of water values need to be measured. This can be quite annoying to do that manually all the time. So I just started automating the measurement of them via Tasmota. One of the leading indicators for a fish tank is the pH level of the water. Measuring the pH level gives you a good indication for several other water values as well. Continue reading

Network segregation: IoT vs NoT

IoT devices became quite popular throughout the last years. Everything is connected, anytime. What sounds like a good idea, might actually result in a security hole in your network. As only the vendor knows what a device is actually doing, your IoT devices might bring some features with them that you don’t like. What is the problem with my IoT device? The short answer is: you own it, but you don’t control it. Continue reading

Starting on a blank page

2018-01-11 meta Michael Kolb
A little bit of History The blog initially started in 2014 and was online till late 2016. I primarily focused on Ham Radio and IoT content these days. These topics were appreciated by many readers. Nevertheless, the old blog had to come to an end as my interests also changed over time. I was simply not able (nor willing :-)) to invest the time necessary to write high quality articles on topics that are no longer my primary focus. Continue reading