Quote Originally Posted by Kitwn View Post

It all worked fine before I started the spindle! I'm using a basic cheapo Chinese parallel BO with diodes to isolate the 5V on it's inputs from the higher sensor voltages. I originally installed the sensors with 12V and have tried 24V but still get the same slight glow on the LEDs.

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Mmmm, just had a thought..... any chance you could post a little pic of the exact arrangement please? The way I'm reading the above, you're using only the bottom 5V of the voltage swing, and hence will only get the noise immunity of a 5V system - having a series resistor or resistive divider would be better. However I may be reading it wrongly!