This device can connect to a Sceme Sensor for measuring soil permittivity and temperature at three different depths. The data gets transmitted to an IoT-Stack for saving the data permanently and displaying it nicely in graphs. The data from a test we run on our terrace can be found here: Grafana Dashboard

The device is powered by solar and an internal battery. It can also monitor the battery. The battery levels get also logged on the dashboard. This prototype also includes a custom-made circuit board.