This happened because of a birthday present.
I was growing Champignon mushrooms in my kitchen storage room, which prefer specific temperature and humidity levels. So I decided to use my birthday present - ESP32, DHT11 sensor, breadboard and some jumper cables - to monitor those values, because why not.
So first I tried to set up the circuit which immediateley turned into a problem when I noticed I needed a 10KΩ pull-up resistor, that had unfortunately not been a part of my present. I thought who on earth has some spare resistors lying around at their home, but it turned out that I, in fact, was that kind of person.
The next problem was to identify the right resistor (10K) in the package I found, because only some were labeled. Looking at a color code chart that also came in the package I noticed I first had to identify which side of the resistors was the right and which the left, because soem pattern were valid read from both sides. Apparently there is no easy and clear indication which is the left and which the right side, except for the distance between the inner color bands and the edge, that should be bigger on the right side (which wasn't too obvious with mine). But I also guessed that a 100KΩ resistor might be more common than a 110Ω one and gave it a try (spoiler: it worked).
For my programm I thought "Python projects are always fun and easy, let's give micropython a try". That turned out to be stupid, because it was missing a library for some part (i dont remember) but I successfully tested circuit. The next evening I switched over to Arduino IDE and the C stuff and after a few more problems I managed to write my sketch with the help of some example code.
Basically the steps are:
- Connect to WiFi
- As long as the connection exists do every hour:
- Get temperature and humidity data
- Get timestamp
- Write data to Firestore
The App part was the easiest and most fun part for me. I wanted to do a quick and simple design and have three main views to see the most recent data, data of the last 24 hours and of the last 7 days. I wrote my Firebase data interface and found a library to display the data in a graph. Finally I selected a mushroom color palette and also drew a silly logo to top it all off.
Tadaa
