Abstract:To improve the range and accuracy of capacitance measurement, a circuit simple and low cost of wide range and full automatic capacitance measuring meter was designed. This intelligent system uses a low cost but strong expansibility ARM microprocessor TM4C123G as the core. System consists of LaunchPad development board and LCD and ICM7555 device etc. Through MPU measuring frequency or period of the signal responding capacitance oscillation circuit implements the capacitance parameter measuring from 1pF to 1 000 μF up to nine orders of magnitude range. The measuring is high precision and full automatic. It can easily help people to measure the capacitance value. The operation is simple, the measurement results is accurate and reliable, the relative error less than 2%, once measuring time not more than 100 ms.