I have made a Mickey-Mouse data-logger using a standalone '328 ( it's not a logger since it only sends data to
a serial monitor, but I'm not a proud man... ). I have used this device to record stuff from solar panels and so on.
I also have a small home-made anemometer on the roof to record wind-speed. Theres a rotor with 3 cups on it.
Inside the case theres an opto-interrupter and a small perforated disc ( salvaged from a computer mouse ). I
made this set-up before I had tried my hand at programming microprocessors and so the output from the
opto-interruper is 'read' by another home-made circuit. Pulses from the interrupter trigger a 555 monoflop.
The O/P from the 555 drives a moving-coil meter movement. The inertia of the meter integrates the 555 pulses.
Yes, it's crude, but I'm not Bob Widlar.
Now I want to upgrade the anemometer and record the wind-speed on the pc. I cant use the datalogger as it is,
since all it does is read a voltage between 0 and 5V. So, how is it done?
Micros have a comparator ( well, some do ) which would convert the pulses from the opto interrupter into a proper
square wave. But then what? The maximum frequency from the opto wouldnt be much more than 1KHz. Somehow,
I would need to start, count the pulses in 1 sec, say, and the send that figure to the serial monitor. Well, that's my
guess, but I'd like others to give me some useful advice,