Acceleration of moving objects is usually measured by photoelectric gates. In this paper, a method of acceleration measurement is proposed by pasting white card stock and black tape on a pulley and then using an Arduino to time the motion. This method only needs one photoelectric sensor to measure the acceleration. In contrast, using photoelectric gates to measure acceleration requires more than two photoelectric sensors, and the distance between the two photoelectric sensors has a great influence on the measurement. This distance is difficult to obtain accurately beyond the measurement range of the general caliper. The pulley diameter required by this method can be accurately obtained within the measuring range of a caliper or micrometer, and variable acceleration can also be measured by this method.