The requirements for them to work are three, that the arduino be connected to a power source such as a wall socket, that the humidity of the ground is less than 65% and the temperature is greater than 30ºC. In the code you can change the requirements, for example you can put the requirements to be different temperatures such as that the temperature is higher or lower than 35ºC, and that the soil humidity is higher than 40%, to monitor the data (temperature and humidity) are placed on an LCD screen.
Submersible water pump DC 3-6V = It is located inside the bucket and is in charge of pumping water through the hose to reach the plant.
Soil humidity and temperature sensor module YL-100 = The humidity sensor module is in charge of checking if the humidity that the plant has is good or it lacks humidity and when it detects that it lacks humidity it sends a signal to the Arduino so that the pump activates and begins to send water through the hose.
Soil temperature YL-100 = Measures the soil temperature and if that temperature is good for the plant (the soil temperature varies depending on the plant) and on an LCD screen these 2 data are shown the humidity and the soil temperature.
LCD display = To show current plant data.
Printed Circuit = To make the connections.
transistor 2N-2222A = Controls the on and off of the pump is an electrical switch.