Measurement Uncertainty Analysis of the Embedded System of Microcontroler for An Accurate Timer/Stopwatch

In the digital era, time measurement is more widely used in everyday life. The need for exact time measurement for online business transactions and telecommunications to record time in running competitions requires validation and traceability measurements to SI units. A popular embedded system of microcontrollers with a timer facility from the oscillator frequency can be used as a timer/stopwatch application, primarily scientific measurements of velocity. This activity proposes a serial communication method. This study intends to analyze the estimated accuracy of time measurement on the embedded system device of the microcontroller. From the experimental results of measurement and calibration of time to almost 4 minutes on the ATmega328P microcontroller sample with a clock speed of 16 MHz, the resolution can be set around 1 ms through a 16-bit timer/counter facility. These results are traceable to SI units through Cesium atomic clocks with error and measurement uncertainties reaching 0.3 and 0.1 s, respectively. The proposed serial communication software method successfully helped to establish this research. A systematic error has occurred, possibly due to delays in data transmission. Human reaction time and communication delay in calibration activities need to be improved to increase accuracy. Therefore, the microcontroller as an embedded system deserves to be applied as a timer/stopwatch related to its application by an accuracy under 1 second, essentially related to velocity and sports competition.