Do I still need to wire the z probe with resistors when using marlin with z probe support on the ramps, or can I just plug it in?
You can wire a mechanical switch between the digital pin and ground, sure. In marlin your pull-up resistors should already by enabled and if you’re coming from a mechanical endstop board, you’ll need to flip the “endstop logic inverting” parameter.
What do you mean? Lol I’m not familiar w any of this.
Yes, you can just plug it right in, but if your head keeps driving down through the bed when you start a print, see my previous response. It’ll probably be too late by then though.
Id rather have a z probe.
By probe, do you mean one of those cylindrical inductive probes that run on 12V? If you plug that in without a voltage divider (resistors) on the output, best case is you fry the input pin you’re trying to use to read it.
Hmmm… I interpreted the question as a simple mechanical switch. More details always welcome.
Oh yea. I meant s inductive one. So can I use any resistors that are n and 1.5n ohms?
Even 10 and 15 ohm or 100 and 150 mega ohm?
I’m not sure what the internal resistance of these things is, but if it’s low and you use 10 and 15 ohms, you’ll have a total of 25 ohms from 12V to GND, which will pull 480mA and put out 5.76W of heat between the two of them. In addition to being incredibly wasteful, this will be over the wattage rating of any resistor you’re likely to have, and will burn them out (unless it destroys the probe first). I’d use resistors no lower than 500 ohms, and about 1K/1.5K to 10K/15K range is probably ideal. Using resistors in the megohm range, you’re likely to get noise drowning out your signal.
Thanks!