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

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

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

10002 Short assembly run no 2

Intro It is quite clear that my smart home project is going quite slow and erratic. Following the other assembly, I made another batch of 5 sensor nodes. These are meant to use the new soil sensors, once they arrive. Since plants will be both outside and inside and we are talking about rain and water, the sensors will go into waterproof boxes, with the soil sensor connected via a cable. So, this assembly is due… 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 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

10002 Temperature sensors?

Intro There is no doubt, that integrated temperature and humidity sensors are the way to go at the moment for my smart home project. I had quite a bit of look at a wide range of sensors and settled for the SI7021. Silabs has a bigger family – most likely the same chip binned on precision – so here are cheaper options to use if I ever want to go for an application that can do with… 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