By: Jonathan Envall (je223rk) for 1dt305 'Tillämpad IoT' @ Linneaus University.
A DHT11, temperature and humidity sensor, is used to gather information about air humidity and temperature. The sensor is connected using a LoPy4 and the data is sent over WiFi to be displayed with the help of the pybytes dashboard. The time frame for this project is a few hours, less if one has previous experience with micropython and Pycom devices/pybytes.
Objective
My original project idea was to monitor the soil moisture level on a specifically cherished plant at my home. But having ordered two sensors of the type "Capacitive Soil Moisture Sensor v1.2" and not managing to get either of them to function properly, I have instead gone with a simpler project where I gather air temperature and humidity data seeing as I already had purchased this sensor.
The soil moisture sensor behaved very differently on different input pins of the expansion board. This is expected since the different inputs have different characteristics, such as impedance, however even when the sensor seemed to be giving a reasonable value, said value never changed even though the sensor was put into a glass of water. And having already spent a decent amount of money and the course coming to an end, I decided not to try and order a different one.
 Fig 1. The capacitive moisture sensor that wouldn't work.