See this pageb for how to add a Hall effect sensor - an Arduino is rather a complicated way of doing it!

http://www.jeffree.co.uk/pages/ml7-cnc/part-3-files/myfordcncpt3.htm

HE switches that give a digital ouput are easily available, and even if you don't have one you only need a simple op-amp and a couple of resistors to square up an analogue output.  The A1101 that Tony Jeffree uses are a pound or two, save you even that trouble.

Oh I fully realize that this is a very complicated and highly unnecessary way of doing this!

This is me being highly impatient and wanting to cut threads ASAP, not even for any specific project, more to test out my recent conversion.

I will be ordering a hall effect switch to do this, I think that will make a very simple solution.

Thanks for the link, I appreciate it. I am very interested in squaring an analogue output, as that would even allow me to use my current analog hall effect sensor most likely.

So I set up my connection to my G540 and modified Mach3 and I got no reading at all on my spindle reading.

I had a digital out from my Arduino going directly into a Pin 1 which is the DB25 pin 10, and everything else is the same, basically my motors are connected, and working and nothing else.

I am wondering if there is anything I am missing.

I confirmed that I had a high low output from my digital output pin on my arduino.

All I really did was went into Mach, ports and pins, went to index.

I set it to Port 1 and Pin 10 and applied and rebooted my machine.

No results, meaning the spindle never changed from 0.

So I played with the other settings, emulated and active low, tried all combos and still nothing.

Any ideas? I know this is not the right way to do this, but what I am doing should simulate a digital optical or hall sensor, so I assume I need to work this out to get the right solution to work as well.

Did you tell Mach your spindle was started by either commanding a M3 or pressing the spindle button?
Hood

No, I did not.

So I should just click the spindle button on the Mach3 command icon bar on the bottom of turn?

Yes or MDI a M3.
You may also have to set the spindle relay up if you are using the parallel port, just set it to any unused output number and then enable the output.
Hood

Hood, Thanks.

I tried pressing the spindle button, still no reading.

I will un-Disable the relay and see if that works.

Thanks for your help, this is not easy.

Yes I seem to recall that is needed when using the parallel port, its been a long time since I have used it however so maybe it has changed but dont think so.
Hood

I didn't have to do anything with the relay or M3 but just click the spindle button.  Have you checked the  pulse polarity?

John, do you mean have I checked with a multimeter whether or not I am getting a positive voltage?