Computer Science – Input and output devices | e-Consult

Two suitable sensors for this task are:

• Soil Moisture Sensor: This sensor works by measuring the volumetric water content of the soil. It typically uses a resistor or capacitive sensor that changes its electrical resistance or capacitance depending on the amount of moisture present. Higher moisture content leads to lower resistance/higher capacitance. This is appropriate because it directly measures the condition of the soil – whether it is dry or not. A low reading indicates dry soil, triggering the watering system.
• Temperature Sensor: While not a direct measure of soil moisture, a temperature sensor can be used in conjunction with a soil moisture sensor. Soil temperature can provide an indirect indication of dryness. Dry soil tends to be cooler than moist soil. The temperature sensor works by measuring the electrical resistance or voltage change caused by temperature variations. This is appropriate as it can help to avoid watering when the soil is cool (e.g., after a recent rain) and potentially prevent root rot. The system could be programmed to only water if the soil moisture is below a certain threshold *and* the soil temperature is above a certain threshold.