I have setup my SKR with Dual End Stops, but I have a few questions/issues.
While the Docs say to wire/use NC switches, when I do this, any ‘open’ switch shows TRIGGERED. (by open, I mean the switch is not depressed)
My dual Z end stops are currently setup to Home Down, and even with the above concern, seems to work fine. (I prefer it to Home Down to Auto Square, as homing down seems to be easier)
However, my X axis is not working as well. The limit switch, shows TRIGGERED, when not homed, and when I try to home X, it moves maybe 1-2mm in the + direction, not back to home. NOW, if I OPEN the Limit switch (by depressing it) it DOES seem behave correctly.
While having a Z Max would be GREAT to prevent the Z rails from poping out of the lower guide, Is there a way to set a ‘max’ in the firmware? (I understand that if it isnt homed correctly, that software/firmware limit will be inaccurate.
Is it still correct that if I have my Z switches set for Zmin, that I wont be able to use the Zprobe?
The V1 firmware solves a lot of this, like Jeff said.
If for some reason you really don’t want to use it…
NC switches are generally recommended because if they become disconnected they will read as triggered. This generally results in something that will not damage your machine. In order to use them, you must enable the pullup resistors, and set them to triggered HIGH. You must also be sure to wire the switches between SIG and GROUND. Do not connect the +5V (or +3.3V) line tot he switches at all. The pullup resistors will bring the voltage up on the signal pin when there is no path to ground through the switch, so when the switch is presses and the connection opens, the pin goes to high voltage. if you enable the pullup resistors, and set the logic to high, the switches will work as expected.
Home up is generally safer, as it keeps the tool out of the way, but home down is easier to think of. Weird that this works, what does the board say if you query it with M119?
See point 1
You can set axis limits in Marlin.
There are still ways to do this, but they aren’t easy, and aren’t the way that we generally use the software.
The low rider dual endstop firmware homes up, and the endstops are NC. You can check with M115, it should say v510DL. You can send that from the screen terminal.
So @jeffeb3 - Confirmed it is running 510DL Firmware (downladoed the SKR_DUALLR_2209 for my SKR Pro with 2209 Drivers, made zero changes, simply flashed firmware.bin)
With no limit switches depressed, they all show TRIGGERED (wired as NC)
The firmware expects the X and Y endstop switches to be wired normally closed. The Z connection for the touch probe is normally open. Most likely you wired your switches normally open. With no connection, X and Y would read triggered. Most switches have the COM, NC and NO connections labeled.
If you had just asked me, I would have sworn I wired them NC. Thanks for the suggestion!
Let this serve as a reminder, when asking for help, and getting suggestions, no matter how sure you are, just verify. I did the same thing with the Firmware. While I was/am sure it was flashed with the correct firmware, I re-flashed it (Before I new of the M115 code). And while I was certain i wired them NC, I went and tested.
This community has been great, and I get wait to start making sawdust!
This is a really sticky thing. Because I am often wrong. But I am often sure I am right, so I sometimes have to think of debugging steps that will check the assumptions while moving the ball forward.
If you ever hear the car talk show, they always take the caller’s info as the truth. It’s very admirable.
Working in IT for close to 25 years, in many different levels, in my younger days, people would get angry at you for asking, ‘hey, i know its silly, but FOR ME, will you just verify the keyboard is plugged in’.
I would not be suggesting that they didnt check, sometimes you just need a 2nd set of eyes to point out the easy stuff that you missed/overlooked/assumed.
Even in forums, I totally understand wanting the OP to post a lot of details, but sometimes I see the value in ‘dont tell me anything but the problem’ and let me walk through troubleshooting. I am certain if I had given full details of my setup, I would have told you my switches where NC. (In fact as I re-read my post, I certainly imply that they are!!)
And I should be clear, my reminder was for anyone asking for help, if you get a suggestion, no matter how confident you are of the answer, take a moment and verify. If you guys are going to give me part of your day to help with my issue, the LEAST I can do is make sure I give you accurate information to work with!!
