We have designed an Arduino-based experiment to check the linear relationship between charge and voltage drop in a capacitor. The electric charge stored in a capacitor is determined by the numerical integration over time of the electric current during the charging or discharging processes through a resistor. Instead of using scientific software to obtain the charge data, in this work a low-cost data acquisition system is coded to provide them. A table with the experimental values of electric charge corresponding to different values of the voltage of the power source can be then easily obtained.