My solar power meter consists of very few components: An arduino uno board, an LCD display, a potentiometer, two solar panels connected in series and a voltage devider. It works as follows: after being turned on, it displays a short text on the LCD, (my name) and then displays the voltage, the current and the power that the solar panels produce. The only problem I faced while making this project was that the two solar panels connected in series were generating up to 12V, while the arduino analog ports can read voltages up to 5 volts. In order to overcome this problem, I made a voltage divider with a ratio of about 1:3. The arduino then reads the lower voltage and multiplies the value with the ratio of the voltage divider. Knowing the value of the resistance of the circuit and the voltage at the ends of the solar panels, we can easily determine the current and power of the solar panels. This is what I have programmed the arduino to do. The potentiometer is used to easily adjust the display’s contrast.
