Thanks for information. I will try TFT firmware update. I observed issue with endstop only while working with Merlin firmware (which I started to use because of other issues with TFT). If endstop issue will occure while using updated TFT, I will use external resistor solution.
Thanks for your response. Happy Easter!
Does it mean that picture by @robertbu is wrong?
No, that diagram.is correct.
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Thank you for your answer.
I performed the soldering of the resistors to my endstop pins hack. Was it kind of a pain? Yep. Did I still have issues? Nope! Jumpered Vcc to Signal on all the endstop connections.
The other thing that I did was pulled off the jst connectors plastic on the board. It appears that the connection is so much better (not loose in my case) when I plug in the endstop wires. This also probably was a reason I was having the motors not stopping when homing.
Howdy!
I just received my SKR Pro V1.2 last week. I am having this issue on all axis. The light on the board indicates that the endstop is closed but the axis keeps moving. Should I do the wire solder ?
Also, when I “home” the machine X moves in the positive direction for half a second and stops, then Y moves in the positive direction for half a second and stops, then Z moves in negative to reach zero. But as above, the endstop does nothing to stop it.
Please help 
I can reply with videos if needed.
I do not have the touch sensor (touch plate, touch pad, whatever that thing is) installed
Might be better starting a new thread for your case.
With the switch entirely unplugged, the SKR Pro will think that the switches are triggered. This will result in the behaviour you describe when homing. The board logic is:
- Move towards the axis min until the switch reads triggered. (It already is, so no motion)
- Back off a few mm towards axis positive
- go back more slowly towards the axis minimum until.the switch is triggered. (Again, it already is.)
The X and Y switches for all V1 machines require a normally closed switch, that is, a switch that shorts the signal to ground unless triggered. Z on a Primo requires a normally open switch, which shorts signal to ground on contact.
Another oddity of the SKR Pro 1.2 is that if you do not bend or clip the “Diag” pin on the TMC2209 drivers, the end stop switches will not work at all.
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Thank you. The pins are bent. So I should do the resistor on the wire ?
@ak47ok47 - Welcome to the Forum. As mentioned by @SupraGuy , it is always better to start a new thread (they’re free and easy to do), rather than resurrecting a months old thread. Even if symptoms seem the same, your issue may be somewhat different than is discussed in the older thread.
I’ll try to assist here
Note that the switches only work during a Homing operation. They do not prevent Move operations.
More info required:
- Can you move all three axis correctly using the Move commands?
- Where is the gantry/core when you start the homing? (Middle of the travel, or near the switches ?)
- What are the LEDs showing before you press the Home button?
- What happens to the LEDs after you press the Home button (when the axis “moves for a second”)
- Are you testing homing on each axis individually, or are you pressing the Home button to test all three at once? (Better to try to home each axis individually)
- Try testing each endstop individually using M119 commands. Run the command before pressing the switch, and then again while pressing and holding the switch. Ensure that the correct switch is asserted (for example, when you press X, make sure that Z1 isn’t asserted) What are the results?
The behavior that you describe (X moves first, then Y, then Z) seems odd - I don’t have my machine set up right now to test, but I thought that it would do Z first, then X, then Y. Again, do a manual Move command first (from the middle of the travel position) to verify that all axis are wired correctly .
When you say that the X and Y axis move positive for a few mm after a Home command, then stop, that sounds like what would happen if the endstops are always asserted. The controller thinks that the gantry/core is already at the home position, so it “backs off” and then it still thinks it is at the home position, so doesn’t move closer.
All in all, I think that you may have some of the endstops miswired, rather than the resistor issue described below.
That would be helpful. Please include the status of the LEDs and the results of the M119 commands.
There is an issue where some SKR boards do not properly respond to the endstop being asserted. Search the forum using combinations of SKR M119 endstop (or end stop) resistor pigtail
The issue may be intermittent, but to test, assert the endstops (one at a time) and do a M119 command. If the corresponding LED comes on, but the M119 command does not show triggered, then you probably need to add resistors (solder to board, or add a pigtail - the latter is better IMO).
If the LED is on all the time, and M119 shows triggered all the time, then you have an open circuit (check wiring).
But let’s get the issue diagnosed a bit better before you go down that road…
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No. The resistor used on the SKR Pro is used when the lights come on and the stop does not trigger. Your stops are triggering, so thst is not the problem.
The stops will trigger if you have wired the switches wrong. They should be normally closed, that is they should conduct to short ground to signal unless the switch is pressed. In this state, the light for the end stop should be dark.
They will also trigger if there is a break in the wire, or something is unplugged.
To test that the board is reading the signal properly, you can use a jumper cap between signal and ground on the SKR Pro. Do not put the jumper on the +V pin or you will damage the board.
With the jumper in place, the light should go out and M119 should report the stop “Open.” Remove the jumper, and M119 should report the stop “Triggered.”
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Thank you all, apologies for making a mountain out of a mole hill. My firmware had endstops reversed.
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Are you sure that you didn’t just have the switch wired NO instead of NC?
Howdy, I plugged it the way they came. It was easier to reverse it in the firmware than swapping the wires on the plug.
This is true, and if the machine works for you that’s the most important part.
Consider, though, that there are very good reasons to go with NC endstops instead of NO, most importantly that with NC a broken wire is immediately obvious, where with NO you are blind to it until the machine misbehaves further.
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Hi Guys, i’d like to say that this discussion is confusing and a guide needs to be written and linked accordingly on the website. The current guide link ditects to this discussion with four different drawings. I am new, just trying to get this setup and I think I have just damaged my board.
I wired according to diagram 1. Which is also shown further down the discussion on a paper plate. Firstly on the X.axis. When I switched on I swear I saw some smoke come from around the board where that driver is so quickly pulled out the plug. Now the led light is permanently on. X-axis still works but I am hesitant to go further without an accurate guide specifically for this issue. Have I completely screwed my board? Can you please direct me to such a guide and or a fix? Thanks.
Unplugging a stepper while the board is on is never a good idea.
Also, you are referring to a very old post that is not at all needed for the new boards any more. If you could be a little more specific as to which board you have and what you put where, we might be able to help. Rather start a new topic though, please.
Mate, the post/discussion is related to the skr pro v1.2 board. It is linked directly from the V3 docs guide/how to. I’m using an skr pro v1.2 . It is absolutely still used as the documentation refers to it.
I’m just following the docs webpages, it sent me to this discussion on how to get the end stops limit switches working with this specific board.
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Okay, then pics might help so the ones who still know how the board works are able to chime in.
We have two important discussions going on here.
- We want to get your problem solved and we want to know what happened. Why you saw smoke, what we can do to help you fix it. A new topic will help. We have a lot of experts here that like to help and it can be humbling to post things on the Internet, but that is the cost of the help. You can open a new topic and link to it here and we can help you as well as use it as a warning to people here.
- Should this post be linked from the docs, and are these instructions still reasonable? That discussion should be here. But before we change anything, we need to know what happened to you and your board. Why is it different than the other’s who had this problem and used this solution?
These instructions are for a very specific issue with some of the skr pro boards. BTT sometimes uses different resistor values that work and sometimes not. Are you sure you needed this fix? Maybe the docs need to be more explicit that these instructions are not usually needed.
Why did they work for you? What blew up? My guess is that there is a short between ground and 5V and your 5V regulator is toast. The endstop should be an input on your mcu, so unless you wired 24V to it, that should still be fine.
You’re obviously trying hard to not destroy your skr and you’re working hard on getting your machine running. The docs are supposed to help you with that and somewhere, they failed. I can sense you’re upset that the docs pointed you to a forum post where a diagram is on a paper plate. That isn’t highly polished, but this is supposed to be a rare fix and when we made this post, there were only a handfull of people with the issue.
This is a community effort. V1 is one guy (Ryan) and he does his best to manage this wild bunch of volunteers to making this all work. This solution is supported by the community (which you’re a part of) and any of us can edit the docs to make them better (Ryan has rhe final say to merge changes).
Let’s figure out what happened to your board. Then let’s figure out where the docs lead you astray. Then let’s fix them.
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