So I have a Hall-effect switch type flow-meter that gives out short square wave pulses proportionally to the amount of flow, roughly 0 to 1000 pules per minute. I need to find a way to measure this frequency in order to get some data out of that flow-meter. I have seen similar projects involving Arduino, but I don't own one nor do I want to spend that much money. Is there a simple device that can count these pulses or perhaps some circuit that I can assemble?