Hi,
so I am using a capacitive Soil Moisture Sensor (it says v1.2 on it) to measure the soil moisture (obv) of soil inside a plant pot. The thing is, I had it running for a few days now and the values barely drop. The Soil is still at 100% moisture altought the soil feels very dry up top. Obviously the soil has more moisture if I dig down to where the Sensor sits but that will basically never change, the soil will always have some kind of moisture in it, at least if its inside (outside the sun might dry it to extrem levels). The Value it reads also depends strongly on how deep the Sensor is burried in the dirt.
456
The Sensor Values ranges from 730-80 (if its just in the air, depending on how dry the sensor is) to ~425 if it is submerged in water. Then, if it is Wet but in the Air (just taken out of a glass of water), the Sensor Reads 630 and that value rises which means it is drying and therefore working properly. But then again, putting it in the soil sets it at about 500 and I can bet that it will not change more than 5% in the next few days.
I tried calibrating the Sensor using % maps as follows:
int convertMoistureToPercent(int value){
int MoisturePercentValue = 0;
MoisturePercentValue = map(value, 700, 500, 0, 100);
if(MoisturePercentValue > 100){
MoisturePercentValue = 100;
}
return MoisturePercentValue;
}
I got these values by inserting the Sensor in a glass of completrly Dry soil (out of a bag of dirt) and in a glass of soil which has just been watered.
Now I changed the map to 700,400,0,100 and of course the reading changed to 61% but that won't move now.
Since this sensor is widely used, someone has to have an idea on how to properly calibrate the sensor for sure. Maybe I have done it wrong or maybe the soil really is still 61% wet and I am just too impatient. I could of course set the trigger to water it on something like 60%, depending on the plant but then it would take weeks to get back to 60%... did I map it wrong?
Thanks in advance!
Jan
