The development of a data acquisition card based on USB bus is introduced in this article.It first describes the configuration and principle of this card in the part of hardware design,and then the application program and device driver in the part of software design.Data acquisition program in firmware is also discussed.Finally,this data acquisition card is tested and evaluated in a program developed by Lab Windows CVI,which shows that this car is stable and reliable
In a preemptive priority based RTOS, priority inversion
problem is among the major sources of deadline
violations. Priority inheritance protocol is one of the
approaches to reduce priority inversion. Unfortunately,
RTOS like uC/OS can’t support priority inheritance
protocol since it does not allow kernel to have multiple
tasks at the same priority. Although it has different ways
to avoid priority inversion such as priority ceiling
protocol, developers still have some difficulties in
programming real time applications with it. In this paper,
we redesign the uC/OS kernel to provide the ability to
support round robin scheduling and implement priority
inheritance semaphore on the modified kernel. As result,
we port new kernel with priority inheritance semaphore to
evaluation board, and evaluate the execution time of each
of the kernel service as well as verify the operations of
our implementation.
