Application:

It is use for detecting soil humidity.

Principle:

The soil humidity probe is for detecting humidity, and the voltage comparator is for judging humidity amount; when the humidity is larger than set value , DO will output low level.

Using Introduction:

1."+" connects power positive; "-" connects power negative. Please do not connect reversely, or it will burn the chip. After connection, "P" power indicator lamp will be on and the module will operate normally

2.Clockwise/counter clockwise adjust the blue potentiometer, it can improve/reduce the detection sensitivity. Take "Thermal Sensor" as example, if defaults 25 Celsius trigger, DO output low level is valid; After clockwise adjusting, that is when the temperature is lower than 25 Celsius, it can trigger; if counter clockwise adjusting, then higher than 25 Celsius can trigger

3.When clockwise adjusts the potentiometer to "S" output indicator is on, it represents the adjusting range has surpassed the testing threshold; if counter clockwise adjusting to its max extend, it surpasses the threshold. When adjusting, please do no let them over the threshold, or it cannot be used normally.Potentiometer adjustment is only used for DO port, it has no relevance to AO output

4.AO output is analog value (voltage), and it can detect via MCU AD port