Very cool! All these great new suppliers I never knew existed! A lot can happen as careers change.... And then you retire and take up farming!
I'm cheap too, but my eyes and hands are not what they once were.
for when I decide to change the software. Much easier to unplug the Arduino from the terminal board and move it to my Mac, leaving all the rest of the tach housing, sensor, and wiring still installed on my mill
I gather that this means that the Uno module itself doesn't need all that mill based stuff for reprogramming. I assume it gets its power and reprogramming instructions via the USB cord.
Does that also mean I can use a USB wall wart to power it on the mill too?
Timing thoughts. There is a couple of lines in the code .......... probably all you’d have to do is tweak the 600000000 value to compensate for 81 pulses per revolution.
Ya, I assumed that from reading your program code. The language is a bit new to me, but it's also familiar. And your documentation comments are excellent.
I will probably do just as you suggest.
However, I also want to try to access the Microcontroller hardware counters directly. If it can do all that for me, then why write higher level code that only slows things down.
I hope you don't take offense, but I really want to experiment and learn as much as possible. Those hardware timers are screaming at me!
All of the data I can find online show a Hall effect automotive crank sensor as using 5 volt supply and signal. Wouldn’t need any tweaking to directly interface with the Arduino.
I won't argue with that. But the keyword is Hall Effect. I don't plan to use that kind of sensor because I don't want to put a magnet on my gear. I want to use the teeth themselves to create a pulse in a what is often called a magnetic reluctance sensor. The passing tooth changes the reluctance of the sensor which results in an output waveform at very low amplitude not a 5V square wave.
Note that this example looks like it would work on a regular input because the voltage is about 8V peak to peak. But the amplitude goes way down at slow speeds with minimums well under a volt. No way to know till you test it.
On the surface, it looks like Hall effect is way easier to use, but it really isn't. Magnetic reluctance sensors are much more popular than hall effect because they are more reliable and don't need a magnet or a shutter. In my mind's eye, the circuit to clean up the reluctor signal is probably just a single transistor running at saturation, and a few passive components.
My sensor only has one paint stripe on the target, so one pulse per revolution. For idle curiosity, I just added 9 pieces of reflective tape, so ten pulses per revolution. The tach read 11,000 at a true 1100 RPM, so it’s likely that the software could keep up with 81 pulses per revolution. The tape wasn’t evenly placed so the display bounced around a lot, but it was clear that the software was counting microseconds between pulses and converting to RPM.
This is GREAT to know! THANK YOU!
