I am much more comfortable in software than hardware, but I'm working on a home automation project to track water usage. I have a Dinel AFP-966-S fiber optic sensor positioned over the water meter - and that works. It changes state when the needle moves. I also have a Hobby Boards dual 1-wire counter. If I manually jump the C-A or C-B input to +5v, I see the counter rise in software. Perfect so far.
But I don't know exactly how to connect them because the Optical sensor requires 10-30VDC and the Dual Counter wants 5VDC. The dual-counter has an internal pull-down resistor, so I presumably have to send it a +5v signal to count. How? Surely I can't just connect the +5V and the +12V to the sensor because the dual counter will get +12v.... I guess here is where I'm stuck. Or do I have to tie in an opto-isolator between the two?
My guess is the internal pull-down resistor is working against me? Otherwise wouldn't I just tie a pull-up resistor to +5V and then tie all GND together? The sensor would pull down the logic pin instead of trying to pull it up? (If this is the easiest solution, I could remove the pull-down resistor, but that's a permanent move.)
Basically, I'm hoping the diagram below just needs one more wire, but where to PUT that wire?!