So the new release from mellow sparked a discussion about the necessity of CAN Mellow just released a toolhead board (Fly-sht) (and yes…great name) It can be connected to CAN or directly with USB to the rpi The product page stated that CAN is “better” and USB “signal stability is easily disturbed…

Standard endstops can handle more than 0.5mm overshoot before any damage would occur. I don’t know what the latency is on my Huvud, but it’s not enough to concern me. I will say I tried using usb and had problems. CAN has been 100% reliable, and it’s the only way I would connect a toolhead board goi…

Thank you! 0.5 overshoot - Is that from a datasheet? I never knew that, that’s great, can you share where you got the number from? USB problems - can you expend on the problems did you had?

Nothing from a datasheet. Just trigger an endstop and see how much further the arm can flex before it contacts the body of the switch. 0.5mm is a very conservative number. On my Huvud 0.61 I connected it to usb over the microfit connector. It worked for a while, but now usb is entirely nonfunctiona…

[image] TheLoneDeranger: So the current word on the street is - CAN - low latency low noise USB - higher latency higher noise Is that true? No. Klipper implements an internal system to validate that response time is kept within 25ms ( Multiple Micro-controller Homing and Probing - Klipper…

Got it, thanks! 3 follow-ups: What are the effects of a long USB cable (2m-3m) if any? What are the symptoms of a lot of noise on the cable? more packets retransmission? isn’t it solvable by a better USB cable? Any other reason to use CAN expect cable management? Giving that the bottom line of th…

If you’re asking me, I don’t know the answer to those questions. It’s not something I’ve tested. I use CAN for the toolhead and XY steppers on my Voron2.4 - it works in my setup - I haven’t tried USB on a toolhead. -Kevin

Thanks I’m gonna test it myself as soon as it arrives and we will see what happens

On my Huvud 0.61 I connected it to usb over the microfit connector. It worked for a while, but now usb is entirely nonfunctional on the board. My guess is your custom wiring didn’t maintain impedance all the way through including the connectors. Losing the shielding would change the impedance for…

USB vs CAN performance

General Discussion

jakep_82 August 24, 2022, 7:10pm 10

You can switch the microfit to USB by cutting a couple traces and adding solder bridges. See the top edge of the back of the board.

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USB vs CAN performance

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