Design of a Polychromatic Color Sensor – Based Voltage Comparator Circuit of Soil pH and Nutrient Management Device for Fertilizer Recommendation

A voltage comparator circuit is designed to analyze and measure the amount of Nitrogen (N), Phosphorus (P), Potassium (K) and potenz Hydrogen (pH) present in a soil. Such circuit is designed to analyze and compare voltage-converted color nutrient results to the required amount of fertilizer to decide how much amount/s of fertilizer are to be added to the soil to increase soil fertility which will improve the quality of soil and reduce the undesired use of fertilizers. The levels of N, P, K and pH present in the soil sample are determined using an RGBC color sensor. The color wavelength output of the RGBC color sensor will be converted to a voltage value using a Raspberry Pi connected to an Analog-to-Digital Converter for data acquisition. The converted output is then compared using the voltage comparator system based on the required amount of nutrients and will output the levels of each nutrient as "Low", "Mid", "High", "Sufficient", or "Deficient" then prints out the required amount of fertilizers to be added. The results show that such a process is good to provide the nutrient amount of a soil, thus providing knowledge to the farmer or a simple gardener that this amount of fertilizer is needed. This is an important part of effective and efficient farming because it gives you an exact amount of nutrient reading of a soil and its required fertilizer amount to best grow a specific crop as to which you will be able to maximize the amount of productivity.