Hqve you seen this?
It’s basically what you need. A light barrier sensor detects the passing needle, all you need to do is counting. But I think it could be difficult to set that up reliably outdoors.
Hqve you seen this?
It’s basically what you need. A light barrier sensor detects the passing needle, all you need to do is counting. But I think it could be difficult to set that up reliably outdoors.