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

Step up from 1 AA cell – again

Intro A while ago I have evaluated the powering options for my smart home sensor nodes. One thing was really clear: I would try to avoid small batteries and using anything else besides the common AA(A) sizes. This makes nodes last a long time on a battery that is easy and cheap to find. And I was right about this – the plethora of commercial remotes and sensors that I also used (like the ikea ones)… Continue reading

10002 The hidden database

A long due update A while back I setup influx DB to store the sensor and activity data on my smart home system. And i thought the raspberry pi 3 was not enough to run the server anymore. And moved to a NUC and all was fine. But recently I wanted to upgrade from Ubuntu 18 to 20 and thought about making an image of the SSD first, as a quick and easy way to… Continue reading

ESP-NOW

Intro The wireless sensor modules I built for my smart home are doing fine in terms of battery life without much effort. Typical life is 1-1.5 years for AAA powered and more than double that for AA powered nodes. So I thought I would have a better look at ESP-NOW. That’s because an ideea popped up during discussion with a friend: can he build a simple sensor network, quick and easy, with off the shelf… 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

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 Screens and controls

Intro There is no point in having a smart home if you don’t see interesting information or control things. The traditional way, ever since the concept of smart home came to be, is to have some sort of central control panel for everything. In today’s world, that would be a tablet. In my attempt to do that, I ran into the control panel horror. What else? In parallel to this, I thought about the idea… 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