Science Buddies: "Ask an Expert"

I have built the circuit described be the instruction and used the correct code I believe, but the water only pumps the first time it switches on. How do I fix this.



Moderator: Project: https://www.sciencebuddies.org/science- ... t-watering

Hi - depending on the size of the pot, the type of plant, and how much water is applied initially, it can take quite a while for the soil to dry out enough to trigger the "dry" threshold in the code and turn the pump on again. How long have you been waiting? If you leave your Arduino connected to a computer and look at the serial monitor, you can look at the sensor reading as it prints out. The pump won't turn on again until that number drops below the "dry" threshold set in the code.

You can also try just pulling the soil moisture sensor out of the soil temporarily, which should cause the pump to turn on.