Smart home aka gadget toys for adults. After years of being on the fence last week I finally caved and started my own smart home.
This micro blog post covers the start of my setup:
Now the system includes:
With a server in place and a few devices I wanted to expand things in a DIY direction. Drawing on my hobby elections skills I put together a temperature / humidity sensor from parts.
Going though some of my old box of parts I found:
Instead of writing a program for the board I found this cool tool, ESPHome, that does that part for you. After installing all the parts into a breadboard all I had to do was write a yaml config file instructing ESPHome which pin my sensor was wired to. Setup was super easy. After an initial programming with the micro controller wired to my laptop all the rest was done wirelessly.
With in the hour I had it printing to my Home Assistant dashboard!
Working on the first try, could it be? Too easy… No. After an hour the readings from the sensor suddenly stopped.
After playing with the config for hours I figured it must be a hardware level problem and busted out the mini oscilloscope.
The readings were really weird. The data line was not getting pulled all the way to 3v by the built in pull up resistor. I decided to remove the built in resistor and try some different resistances.
In the end after a lot of reading online forum posts I’m convinced the DHT22 is just a crap sensor. For my next project I’ll defiantly use a higher quality sensor.
As part of the debugging process I moved from the breadboard to perf board, trying to rule out faulty connections.
Once on perf and after not working for a day suddenly the sensor started reliably sending data. 🤷♂️