Abstract:

This report describes the design of digital frequency meter. The system uses TM4C1294 LaunchPad of Texas Instruments as Microcontroller Unit (MCU) to measure frequency and period by capturing the rising edge of input signal. The pulse duty cycle and time interval are measured by a combination of rising edge capture and analog low-pass filtering. When measuring the frequency and period, There are three ways according to input frequency; when measuring the pulse duty cycle, the low frequency is captured by the rising edge, the high frequency is low-pass filtered; when the time interval is measured, NAND gate and low pass filtering are used for the whole frequency band. During operation, parameters such as frequency, period, pulse duty cycle, and time interval can be observed through the screen which this project achive driver codes for. Considering that this is a embedded system, the screen is also controlled by the same MCU.