Blinking bltouch
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I just went through the same issue. I rewired and still had the same problem even thought my bl would be able to drop and lift the pin. I could even probe without any problems. It would just always flash. I ended up removing the top grub screw and seeing how well the pin could move. I found that there was just the slightest resistance as it moved. It could still move on its own but it must be able to tell if there is any lag or hesitation. I used a replacement pin and still had the same issue. I ended up cleaning up the hole at the end of the bltouch body and that seemed to fix the issue. The bl should be able to self test without the duet giving it commands when you first power up. If you are into radio controlled models or drones you can plug it into a receiver and see if it works. Its just a fancy servo after all.
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yep. I took the pin out and checked it out. There was absolutely no resistance. If I turned the BLT upside down, the pin will fall out with no effort.
I also re-terminated the connectors on the Duet side of the cable and looked at them under the USB microscope and they are exactly as they should be.
And yet, it only flashes and does not initialize.
I will look more closely at the changes that @Phaedrux and @PaulHew suggested tomorrow.
I am really baffled. I always hope that it's something that I am doing wrong. That's been the case in the past, but I have been over this over and over and over and I can't find it.
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@crchisholm i would say hit them up. They are a little slow to respond but they may work out a replacement for you. antclabs@gmail.com
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the only thing I HAVE NOT changed is the Duet board. I have ....
- tried three versions of the cable.
- tried two BLTouches...one that has never been used before now.
- checked all the connectors
- checked continuity and resistance on all wires (all wires show 0.4 oms)
- Looked at the pins on both the Duet and the BLT with a usb microscope. All looked good (no bends or discoloration)
- tried all the code changes suggested.
- probobly a few other thing I can't remember now.
The only thing that has been constant through the whole ordeal has been the problem and the Duet board itself.
Has anyone experienced a problem with the BLT and found that there was an issue on the Duet board itself?
I can't really afford to buy another Duet board. I might buy another BLT, but am afraid that's another rabbit hole. Also, this problem went from working perfetly and then not working at all with no changes in between other than not printing for a few days.
Frustrated in Florida!
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How can I determine which version BLTouch I have. Amazon says it’s Antclabs, but does not show a version. I believe I have v3, but not sure.
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@crchisholm If it's a genuine BLTouch there should be a silk screened version number on the PCB.
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If you don't have the cut trace you probably have a v3. If it has the trace then v2
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Ok, I have v2. Was there much improvement between v2 and v3? I just ordered another v2 (now I know - wish I had waited.).
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@crchisholm the v3 is native 3v tolerant now. No more resistors or traces to cut. Not sure what other tweaks they may have made. The v2 is still very capable.
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@Phaedrux Wow. There may be clue in this. I just got the BLTouch and to my surprise, it is a v3.1 Some time back, @dc42 had sad that I did not need to add a resistor or cut the trace any more, but he may have thought I had the v3.1. I did not cut the trace or add a resistor because of that. Even if that is the case, certainly, no blame on DC42. I did not make it clear what version I was using because I didn't know it made a difference.
If that's the case, maybe I blew out the other two BLT's. (both v2)
Does that sound likely?
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@crchisholm said in Blinking bltouch:
If that's the case, maybe I blew out the other two BLT's. (both v2)
Does that sound likely?No. You would blow a BLTouch if you applied significantly more than 5V to it. It might also be possible to blow the output driver in the BLTouch by shorting the output (white wire) to ground or to +5V or +3.3V, but without the schematic I can't say whether that is likely or not.
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Hu-ray!!!
The new BLT v3.1 works. After I established that, I plugged in the old ones into the new cable and they still didn't work, so I think that means that the two v2's are tiny boat anchors. I still have to unmount the old BLT and mount the new, but I suspect I will be printing again tomorrow.
Happy Me!!!!
Thanks for all the suggestions and help I got on this thread. Wish I could buy you all a couple of coffee and a dough nut.Charlie
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Glad you have got it working again.
How old are the others, you might be able to return them under warranty, might!
However, brilliant and look forward to seeing your first straight print!
Paul
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Hey Paul,
I looked up when I bought them and it was January of '19, so i had them a little longer than I thought. Looking at it that way, I guess that's an ok life span.I'm just happy to have it working.
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@antlestxp said in Blinking bltouch:
If you are into radio controlled models or drones you can plug it into a receiver and see if it works. Its just a fancy servo after all.
That is an interesting idea. Can you tell me more about how that works. I have a RC tx and rx.
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you would just plug the bltouch 3pin cable to a reciever. With a programmable radio you can set a toggle switch with the correct limits to toggle the bltouch in and out. I think it is pretty tough to damage a bltouch. Maybe the v2 are just configured wrong.
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There is a possibility the set screw is t far in enough - it also serves as the steel piece that the magnet in the pin gets attracted to. Once I had an issue where it wasn’t down far enough.
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@crchisholm, I had this exact problem, I have a v3 as well and for months this was driving me crazy. sometimes it would self test fine and then others times not.
before powering up I would pull the pin all the way down. and then sometimes that would help assist with a successful test. Other times unplug and replug power over and over until it would self-test. This weekend I had the idea that maybe the set screw for the pin height wasn't down enough. even though I calibrated according to the documentation. So tonight I turn screw down. in between each screw turn testing with power off/on. no luck. a little bit more still not. a little bit more and dada it works every time! going to run with this and hopefully it's cured! Ah nope, worked until I had to home the Z axis. so move set screw around more and still not self-testing.
resetting M280 P0 S60 and the M280 P0 S10 to test. blinking... voltage is good. 5.2v.okay I have spare PIN... put in. self-test fine. run M280 P0 S120 works good. run again. works good. run again. works good. M280 P0 S10 deploy perfect M280 P0 S90 retract perfect. Z Home perfect!
Wondering if the magnet lost some flux...
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I just wanted to pop in here and say how I resolved this issue of a blinking BLTouch after replacing the pin. Apparently the new pin was not properly formed when cast. After hours of troubleshooting I took the BLTouch apart, removed the pin and sanded it lightly with 400 grit emery paper. I then put a very light coat of silicone lubricant on it and reassembled. After this it worked just fine.
