Abstract:

Aiming at the updated verification regulation of stopwatch and inconvenient carry of verification instruments, we propose a design of stopwatch calibration instrument based on FPGA. Firstly, we use Verilog hardware description language, take Quartus II as the software platform, and employ a modular design with high time accuracy of FPGA. The accurate timing results are displayed by the driver circuit of nixie tubes. The innovative use of electrical/machine conversion device  for hitting the stopwatch enables more accurate triggering and  improves the detecting accuracy of the subject stopwatch. The design has a clear division, and consists of a frequency module, a control module, a timing module, a time setting module, a position setting module, a display control module, and a servomotor control module. The system adopts a topdown module design method, and features fewer peripheral circuits, high integration, strong reliability and other merits. Experimental results verify the high precision time. It can detect the timing accuracy of the stopwatch very well, and is very convenient to carry.

Key words: FPGA;stopwatch calibration instrument;modular design;the mechanism of hitting the stopwatch;electrical/mechanical conversion device