Solar panels for sensor nodes

Intro For a while now, I started replacing the dead AA(A) batteries in my sensor nodes with rechargeable NiMH ones. So, since these batteries are rechargeable, I thought, why not trying adding small solar panels for sensor nodes, where light is abundant. Node 27: outside sensor Purpose: outside temperature, humidity, light, pressure sensor. Powered by 2 x AAA 500mAh from Ikea. The solar cell is rated 3V, 125mA and is pointing vertically south and costs… Continue reading

Simple LED strip UPS – closed.

Update after 3 months The UPS is functioning as it should, and I think the solution is viable as a simple, low cost UPS where it is needed. It was a good mind and build exercise, but there are two reasons why I am not keeping it: First – realistically speaking, electricity fails way too seldom to actually use it.  Second, unless I build one of these for each room, I will always have to… Continue reading

driving a string of anti parallel LEDs

Intro I have quite a few strings of LEDs with clips for photos. Never thought it was much more than a gimmick when i got the first one, but they do make for nice and personal decor with the photos attached. So naturally the next step is to control them through the home automation system. The first one was easy, there were all LEDs in parallel and an ESP8266 module and a tranzistor was all… Continue reading

Fast 3D printed boxes

Intro Finding the proper box for my sensors is not easy. But even after finding one that mostly worked, I wanted to explore more sensors and still have a bit of freedom while doing that. Of course, that means 3D printing with the new 3D printer. There is just one problem …. 3D printed boxes take a long time to 3D print. An example Here is the newest sensor module I designed, which can fit… 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

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

10002 Control panel horror

Intro I have been making some slow progress with my smart home project. I have completed a small assembly run of motion sensors, there are plenty of things that are working and I shifted some focus on making a control panel. What I normally want is a control interface that works well from both a PC and a phone. Bonus if it can look nice on a tablet to have one real control panel on… Continue reading

10002 Short assembly run

Brief progress It is quite clear that my smart home project is going quite slow. It is not that I spent a lot a time on it, but that I have been pretty busy with other life things. But it is moving again now. Check out another batch of assembly. Motion sensors assembly Once I settled on the type of motion sensor and case, I designed some sensor PCBs . I made a small assembly… Continue reading