Advancing Embedded System Design: FPGA-Based Digital Frequency Meter with Adaptive Range Commutation

Abstract

Frequency measurement is crucial in electronic measurement, and digital frequency meters are essential for engineering. Their use in smart appliances increases demand for wider ranges and complex designs. This paper presents the design and implementation of a digital frequency meter using FPGA technology, in particular the Xilinx Spartan 7. The system incorporates automatic range commutation, providing frequency measurements from 0.01 Hertz to 9.99 Megahertz. The frequency is displayed on a three-digit display with two decimal positions, while the range is shown on eight LEDs. Measurement is based on counting signal cycles within a time frame defined by a basic time generator. When the frequency exceeds the counting limits, the system automatically changes scale. The development part of this paper is divided into two steps: first, a digital architecture is designed using VHDL software for the combinational and sequential logic functions, preceded by validation by simulation. In the second step, analogue conditioning circuits are developed, including filters for noise reduction and a comparator for signal shaping. The system is tested with a signal generator to validate the functionality of the FPGA-based frequency meter. Findings show that the FPGA implementation provides accurate frequency measurements with effective automatic range commutation.