Design And Embedded Research Of Key Test System

The test of keyboard lifetime is a repetitive, mechanical work. The test times of each detected key are in one million or more times,which is almost impossible by the manual test, because manual test is poor in consistency with big error,however, the performance and life of the keys is a must be tested indicator, and key test system can be a good solution to this problem.In the analysis and comparison of key test system at home and abroad, based on the specific context of engineering applications and analysing functionality and performance requirements of the test,this topic uses ARM7 data acquisition card based onμC/OS_II and software based on LabVIEW to form a complete key test system Slave machine applies Philips's LPC2131 chip controller, uses fuzzy PID algorithm to control servo motor accurately, chooses conversion chip ADS1255 with 24-bit to achieve signal conversion with high-precision,increases the system anti-jamming capability. through the master chip I/O port scanning high-speedly to count displacing pulse signal and the interface with the outside through the opto isolation, The development of host computer software reached by LabVIEW graphical programming tools,combining with RS232 serial communication enables complex data acquisition, processing and analyzing to achieve the display of the current value and testing curve, data preservation, report generation and printing. The Paper describes the system hardware design, software development and control research, as well as investigates the problems of hardware and software anti-interferenceThe result of commissioning indicates that the system can meet the requirements of the testing key performance and feature user- friendly interface,high measurement accuracy,and ease to operate,etc It has been applied in practice. The architecture of hardware and software in the system , not only can be used in key test system, but also for other occations of data acquisition, has a strong versatility.