Sensorless homing w/out diag caps on controller

General Discussion
1

Printer Model: Anycubic Chiron

MCU / Printerboard: Trigorilla v1.0

Host / SBC: Raspberry Pi 2b

I’ve got an Anycubic Chiron with the stock Trigorilla 1.0 board flashed to Klipper and I’ll be installing some TMC2209 drivers and setting them up for UART mode this weekend. I was also hoping I’d be able to set up Sensorless homing with this setup.

Everything I’m finding online references newer boards that have the diag jumper caps on the board to enable sensorless homing. I’ve seen a few videos on youtube where people reference “older boards” needing a wire going from the diag pin of the driver to the controller, but I can’t find any info on where it would need to go. Do I just disconnect the X stop switch and run a wire from the diag pin on the driver to the signal x stop pin on the controller? Is it that simple and I’m just overthinking things too much or is there another point that needs to be tapped into on the controller board?

2

Trigorilla boards, especially the early ones, are really quite difficult to work with and have no documentation other than what other users provide which makes it spotty and suspect.

If you’re going to the expense of buying TMC2209 stepper driver modules then I have to recommend that you get yourself a new main controller board.

Personally, I would recommend the MKS Robin 3.1 or BTT SKR 1.4 (Turbo) in which you should be able to get sensorless homing working without any issues and there’s lots of reliable information and support available.

I just notice that this is in “Features” - it should be in “General Discussion”.

3

Why bother implementing sensorless homing if you have working limit switches?

IMO this “feature” is simply a marketing ploy. The main advantage is it saves the company a couple $ in switches, wire, and assembly time. Somebody in marketing overheard the engineers talking about it and thought “that sounds high tech, we should sell it as a feature”.

Edit: Is sensorless homing REQUIRED to enable UART mode?

1 Like
4

There really isn’t much documentation, but people have already done this and I’m following their working examples to get the TMC2209 setup into uart mode. I’ve already got them set up in standalone mode, but I’m getting tired of flipping the machine just to adjust the vref when I try to go faster and the motor skips w/out heating up. Let’s just say I’d like to keep running this board until it actually stops working, because it’s still working perfectly. Once it dies, I was thinking about using an SKR 3 instead of the 1.4 turbo. I appreciate the input, I’ve already thought about it, but it’s not something I want to do at this time. I’m stubborn.

That being said, I’ve heard that it can be set up if the controller doesn’t have diag pins onboard, but everyone says it’s messy. I’d like to know how messy and what the basic process is. I’m assuming it’s a generic idea or process that can be applied to any printer(like run a wire from the driver to the x stop signal pin or something like that).

I’m not asking someone to do my homework and isolate the exact pin on the board and circle it in the picture for me. I’m just looking for some info regarding the general process, or at least someone confirming that it can’t be done if the controller doesn’t have the diag pins to jump.

My bad on dropping it in the wrong section. I thought since sensorless homing is a feature it would be better to talk about it here.

5

I’m upgrading my extruder to a Co Print Chromahead and it doesn’t have an x stop switch onboard like the orignal Chiron print head was designed with. I know I can relocate the x stop switch to the gantry, but I’m hoping I can just use sensorless homing to prevent needing to relocate the switch.

EDIT: From what I’ve read, sensorless homing won’t work in standalone mode. That was from the Klipper docs. TMC drivers - Klipper documentation under Prerequisites. Sensorless homing isn’t needed to set up uart, but uart is needed to do sensorless homing.

6

Moving the switch Sounds to me to be a better route than modding (and perhaps ruining) your mainboard.

7

It also involves designing a mount to hold the x stop switch. That is more work for me than a little bit of soldering or running wires from one spot to another. Besides, if I end up frying this board, I’ll be able to justify a new board purchase. Not that they’re expensive, but I don’t feel like upgrading the board just for sensorless homing on one axis is enough to justify the change.

I’ve been an IT repair tech for over 20 years and have much better soldering skills than I do 3d design skills. lol

8

Good. You’re going to need to be.

“Everyone” is right.

Actually, that’s exactly what you should be asking for.

I’ve been through the process three times on Anycubic printers/Trigorilla boards and it’s, I don’t want to say “hell”, but I can’t think of any other way to end this sentence.

If you’re really determined to do this then:

  1. Make sure you’re comfortable doing SMT rework and adding fly wires as well as cutting traces on a PCB
  2. Have a good soldering iron suitable for lead-free soldering with a fine tip. If your phone can’t do close up pictures, then I suggest you buy a cheap USB “microscope camera”
  3. Start with getting UART communications working. On a number of Trigorilla boards, you will have to relocate resistors while in others, you’ll have to cut traces and run fly wires (see point 2). When looking for instructions on doing this, make sure the instructions you are referencing has pictures of the same board as you have
  4. Once you have that working, start on sensorless homing. Depending on the board, you’ll have to take MCU connections from unused features or no longer usable features (ie the LCD display). Again, make sure the instructions you are referencing has pictures of the same board as you have
1 Like
9

Make sure you’re comfortable doing SMT rework and adding fly wires as well as cutting traces on a PCB
Have a good soldering iron suitable for lead-free soldering with a fine tip. If your phone can’t do close up pictures, then I suggest you buy a cheap USB “microscope camera”

I’m good on that. I’ve done the 30 wire wii modchip drive installs in the past. Been working on smd and bga reflow/chip replacement for quite a few years now. I’ve got experience with a dark IR machine, but don’t have access to it anymore. Just recently, I performed a 128mb ram mod to an original xbox. The soldering and trace cutting/rebuilding I’m pretty good at. Not an expert, but not a noob. I’ve got a nice hakko 907 soldering iron handle with an aftermarket controller cuz the original box died after a decade.

Start with getting UART communications working. On a number of Trigorilla boards, you will have to relocate resistors while in others, you’ll have to cut traces and run fly wires (see point 2). When looking for instructions on doing this, make sure the instructions you are referencing has pictures of the same board as you have

That’s the number one goal this weekend. The guide I’ve seen, with the same Trigorilla 1.0 board used on another Chiron basically shows soldering pin headers to the servo ports, then running a wire from the uart pin on the drivers to the proper servo pins. That part seems easy to me and I’ve got a guy in a facebook forum helping me out and giving me some good advice based on what he’s already done. For reference, this is the guide I found that the guy on facebook confirmed is what he did and even showed me pics of his setup. Anycubic Kossel Klipper Trigorilla TMC Driver UART Upgrade - Lukas Pomykal Same board, different printer, but the skills and ideas are transferable.

Once you have that working, start on sensorless homing. Depending on the board, you’ll have to take MCU connections from unused features or no longer usable features (ie the LCD display). Again, make sure the instructions you are referencing has pictures of the same board as you have

Thank you! I think that was basically the guidance that I needed to try and get this going. I did ditch the lcd a while ago, so that might be the best option, but I’ll see if there’s anything better to pull from. This printer used some extra daughter board connected to one of the exp ports and the stop switches. So going with the lcd might not be the simplest, but that’s the bit of info I was hoping to find. I’m assuming it needs to be addressed to a digital pin, not an analog pin, right??

I’ve also done electrical engineer work for a few years in the past, so I’ve got a basic understanding for reading schematics (unfortunately there isn’t any for this board), and following traces as well as using a multimeter to confirm the traces are going where I think they are. I’m just “new” to 3d printing. I only started about 3 years ago and I only started using Klipper in the past year and a half. It’s stressful at times, but that’s part of what I love. I’ve always loved making hardware do things they weren’t originally intended to do without releasing the magic smoke. lol

Thank you for the guidance in this, and I promise I won’t come back complaining if I fry anything. I understand I’m pretty much on my own doing this, but in addition to being stubborn, I’m determined. lol

10

Please don’t think that we’re not here to help if you run into problems.

As I’ve said, I’ve been through the process before with Trigorilla boards before and I’m sure I can help out with questions as you go through the process.

Good luck and let us know how you are doing!

1 Like
11

Thank you. To be fair, I didn’t mean I’m on my own in the sense that I feel like no one is willing to help, cuz that’s not the case. I meant it more from the viewpoint of no documentation and I’m working with a generic idea to try and find the solution. I wasn’t able to find anyone who did sensorless homing on a trigorilla board, so I might be the first person foolish enough to attempt it… I think I’ve got it, but I’ll update on here once I complete it(or give up) to share what I did.

1 Like
12

I couldn’t wait until the weekend to get started on this. Following the info I’ve been able to get the drivers to work in UART mode perfectly fine. The only thing I haven’t located is the pin info for the 2 drivers for the z axis, but did mange to find a printer.cfg file that was set up with tmc2209’s on x and y with sensorless on X. So clearly I’m not the first one to attempt this set up. After reading the info they dropped in the file, it told me which pin to use, but it also said the x stop pin could be used. I ran a wire from the diag pin on the x driver to the x stop pin and I’ve been able to successfully configure the sensorless homing on the x axis. But basically the guidance of using an unused pin helped a lot.

Thank you for the help @mykepredko Much appreciated. Now I can focus on the real fun part I had planned for this weekend. Converting this printer over to a 4 color printer with the Co Print Cromahead extruder kit.

I’m also attaching my Klippy.log file to this post. In case anyone else wants to attempt this. TMC2209 drivers are set up in UART mode using the standard diagram for the Anycubic Kossel printer, I used a Biqu H2 V2S extruder for this build.

klippy(5).log (239.9 KB)

1 Like
13

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.