Accurate Current Measurements for the Estimation of the Power Consumption in Wireless Modules

Performing accurate current drain measurements of wireless modules is a critical test for portable electronic systems because their power consumption has a major impact on the battery lifetime of small and middle-size embedded systems provided with wireless connectivity. In spite of its importance, this measurement problem is not obvious due to the considerable variability of the current waveforms drawn by such modules. In this paper the problem of optimizing average current measurements with a low-cost multimeter (DMM) is addressed. In particular, after identifying the main sources of uncertainty affecting the measurement procedure, some guidelines to estimate and to keep the standard measurement uncertainty below a given target value are provided. Finally, theoretical and experimental results are compared in a real case of study