firmware wip - set dry value for analog soilmoisture to 300, measured with dry soil.

Arduino/CanGrow/CanGrow_Sensors.h

@@ -146,7 +146,11 @@ int getSoilmoisture(byte moistureSensor, bool returnRAW = false) {
     case 1:
       // read analog value from analog moisture sensor
       wet = 180;
-      dry= 590;
+      // this value was measured in air, without contact to anything
+      // dry= 590; 
+      
+      // was measured in dry soil, not bone dry but really dry (6 days no watering)
+      dry = 300;
       
       //digitalWrite(PINsoilmoisture, HIGH);
       // wait a bit to let the circuit stabilize