HCSR04.device.nut - busy loop timeout?

[jmcgnh]

What are the considerations for having a busy loop timeout of 500ms? Isn't this long enough to potentially interfere with other ImpOS functions? I realize that this method may give better accuracy, but how bad would it be to rely on an interrupt and callback instead?

I was thinking of implementing it along the lines of

https://gist.github.com/cat-haines/5492082

But given that the range of the HC-SR04 is not more than 4 meters, my calculation says that the timeout value should only need to be something like 25ms.

[ppetrosh]

I have no clue on why 500ms was used. And having looked at the code, I really think it can be improved.

If you play with the code and find a better solution which reliably works, please feel free to file a PR with your changes.

[jmcgnh]

I've done a few experiments today, relying entirely on callbacks rather than busy loops. It "sort of" works, but my experimental/exploratory code is quite messy and there are a few unresolved problems. In particular, the instrumentation to watch how it's working is interfering with the ability to catch events on the 100-microsecond scale. Thank you for the invitation to contribute. I'll keep working on this until I have something worth showing.

[jmcgnh]

Didn't intend to close.