Wet sensors (or humidity sensor troubles)

Intro Well there is no surprise: i went through a lot of temperature and humidity sensors. Some I already reported on, and some more i tried afterwards. And none seem to survive the exterior readout very well. The defects are mostly related to humidity, but not temperature. What happens when they fail: mostly the humidity saturates to 100%. Here is my most recently replaced one from outside, a BME280: After a while, the sensor reads… Continue reading

The basil speaks to me – Part 2

This is highly experimental But of course, once the soil moisture is read out, it’s only a matter of time before automatic watering has to happen. Add one beefy (..ish) MOSFET and a small pump You get one basil with automatic watering. The setup now looks like this The watering algorithm Is very simple: I wait until the moisture level drops under a low threshold. Then I go into water mode: as long as the… Continue reading

10002 Server

Intro In my initial thoughts about the smart home system architecture, the server was most likely a raspberry pi: At that time it seemed the PI was apt for it. And a raspberry pi 2 served me well for a while, and then I moved to a pi 3 and everything was good. Until it was not enough… What happened? I had mosquitto and node-red as the main things running. And I added some simple… Continue reading

10002 I2C connectors

Intro In my first iteration of sensors I relied on wire connections between sensors and the actual node board. The result for a motion sensor and a temperature and humidity sensor looks like this The problem with that is that during sensor modules assembly run I spend quite a bit of time on the wiring. On top of that, the result is a mess of small wires inside a box. It makes it hard to… Continue reading

10002 Zen

Zen At some point I though about building the smallest PCB for a sensor node that I could. Hence, the ZEN was born. The PCB is small enough to fit on a holder of 2 AA batteries. Where I have only build a few of these. Here is one reading the soil moisture sensor on basil. Here is another one chilling in the fridge, reading a temperature sensor. And here is one replacing the alarm… Continue reading

The basil speaks to me

Check out part 2, where the basil is watered automatically. Intro Part of my home automation system is monitoring the well-being of various other non-human species around the house. So i started with the plants. Since they are mostly fixed creatures and generally require only water input from humans, monitoring the soil humidity is a good start. How There are quite a few ways to measure how much water is in the soil, some of… Continue reading

The coolness of RGB LEDs

Intro Ahhhh LEDs….don’t we love them? Today there is a huge variety of them. But there is one type I particularly like. These 5 mm RGB diffused LEDs, easily available from various sources and quite cheap (amazon.de, aliexpress, ebay etc). Here’s why I like them They are super bright. According to some datasheet which may or may not be what you are buying from less reputable sources, the green LED peaks at 5000 mcd at… Continue reading

Vorpal hexapod

I wanted to have a hexapod robot for a long while now. It just never seemed to be that much of a priority to spend the time or money to build one. Luckily this changed when I found Vorpal. They are selling complete kits or you can build one yourself from the plans that are provided. I was missing only a few servos and the 3D printed pieces, so I quickly decided to build one.… Continue reading

10002 Architecture and Software

This article is part of my 1000² Smart Home project. Check out the Architecture and Software and then move on to Hardware. An most importantly, check the Lessons learned and why I did what I did. There are already some first results, connecting all parts of the system. Starting with a top down approach – what the system should do, it soon became clear that some devices will be custom and some will be off the shelf. Determining… Continue reading