I implemented vApplicationIdleHook just like in the ebook. Every second, I have a task which prints out the value of ulIdleCycleCount. the value hovers around 2,724,536. Sounds like a nice beg number which, I think, means we have lots of idle time, but I am not really sure. What does that number really mean when I am running a PIC32 at 80MHZ?
Is ulIdleCycleCount a variable that just gets incremented each time vApplicationIdleHook() is executed? If so, then all it is is a count of how many times the function has been called.
2) Use the traceTASK_SWITCHED_IN trace macro to see when the idle task is switched in, and when it is switched out, and use a timer to keep track of when it is the task in the running state.
3) Use the idle hook to toggle a digital output pin and view it on a scope. Crude but effective.