pulsin: how is it used

[dhouston]

As I wrote, PULSIN does not wait for a leading edge. If the pin is already in the the state of the defined "pulse", it starts counting as soon as PULSIN is called and stops counting when the trailing edge is detected. If the pin is initially in the non-defined state, the count starts at the leading edge. The disparity between your readings and your expectations is just due to the limits of accuracy using this method.

However, you cannot use it to time any execution other than itself as it does not return until it detects the trailing edge.

The manual is ambiguous, referring to an edge but not specifying both edges must be detected. Initially, I interpreted it as you (and Bruce) have but found, through experience, that was not the case. Other PBasic derived dialects for PICs that I've used are explicit about waiting for a leading edge.

@BRUCE: If you look at the NEC RF example i posted to Code Examples, removing the statements that wait until the initial space (trailing the long starting pulse) ends, the loop will detect that first space, giving an invalid code as a result.