ESP8266 soil moisture sensing gets dirty

helge wrote 07/30/2018 at 23:05 0 points

We know both the 555-based capacitive soil moisture sensing and the approach to "just stick an ESP8266 on it" to make a wireless sensor.

However the question needs to be asked why the antenna is always OUTSIDE the soil when the 2.4 GHz band lends itself so neatly to implementing microwave absorption measurements in transmission (between any two antennas).

Shouldn't it be possible to dial down transmit power and get soil water content from RSSI. As a bonus one might still be able to transmit to a regular wifi access point using the same antenna.