I'm in the progress of building my self a 40w laser. The Smoothieboard has performed well so far.
My question is if there is any software support for having a output pin set high or low depending on the number of pulses detected per second on an input pin? - I have bought a Flow sensor (not a flow switch) that measures the current flow rate of the water and reports it back in a specific number of pulses per gallon of flow.
The laser PSU has a input that needs to be pulled low for the laser to turn off. The recommendation is to have a flow SWITCH connected to this pin that pulls the pin low when there is a flow. However, the cheap flow switches that is a on/off switch have their mechanical issues where you need a certain amount of flow before the spring is pressed enough and the small amount of flow that is needed by the laser is not enough to trigger the flow switch.
By using a flow meter instead of a flow switch, the threshold value for the amount of flow desired can be handled in the software instead of in the spring tension of the flow switch.
I do have some plans on handling this in a ATTINY85, but doing this in the smoothieboard would be even better.