Hi Chang,
just some advices, more details based on what you actually need,
1. The initialization should be place out side of the loop, ideal would be put only the read/write functions in the loop, the configuration can be place in- or ourside the loop
2. Both channel should be initialize before all the tests starts, only the read/write functions should be place in a loop or case struce for when the action is to execute.
3. Better put two loops for two tasks, one for monitoring the physical channel 1, another one for the physical channel 2.
4. The one with sensor, you can get the edge-state boolean value saved in local variable, and read out from another loop with your case structure.
