USB Hub

Does anyone have any experience with using a USB hub with their machine? I want to connect this to my computer and then connect a few different devices to it, including the usb to my Ramps 1.4. It really will mainly be for my keyboard and mouse. Will this cause any issues with sending gcode, jogging, and connecting to my Ramps board?

I doubt it will be any trouble. The USB has much more bandwidth than the serial chip on the arduino. But I haven’t tried that myself.

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I would doubt it as well. Ill give it a try and report back to this thread for anyone who may be wondering the same thing. Thanks for the input.

I agree it shouldn’t cause problems. I have used a similar device to communicate with controllers for work and had no issues. The only situation I can see it potentially causing a problem is if you start plugging flash drives or external hard drives into it, then try to transfer large amounts of data to/from them while trying to drip feed a program to the ramps board. But even then I’m not sure it would be an issue just the most likely scenario I can think that could potentially cause an issue.

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It’s mentioned in the description for the product, but I think it bears repeating that you probably should not use a passive hub if you’re powering your Arduino via USB as well. You need a powered USB hub for that. To be honest, I would use a dedicated 5V power supply.

The arduino is powered by a 12V power supply. The USB does not need to act as a power supply, only for communication.

My printer used to be on a USB hub, which also had a keyboard/mouse(trackball, actually) so that I could have a keyboard and mouse facing the printer, since the main ones at my desk were troublesome to move around. The monitor was on a swivel, so easier to change. I’d use those with Pronterface to jog the machine around, set things up, make bed levelling adjustments and so forth. Also to browse the web while watching the printer.

So far as I could tell, it never slowed the printer down any.

USB 2.0 has a 480 Mbps bandwidth, and Marlin (typically) is set up for 250000 baud (or bps.) This means that even communicating at absolute top speed, Marlin will take up 250kbps, or 0.052% of the bandwidth available to your USB 2.0 port going to the hub.

Bandwidth wise, it won’t be any trouble.

That said, there is a small inherent latency involved in any hub, but I dare say you’ll never notice it, and something that moves as slowly as you CNC will make absolutely zero difference.

I appreciate the deeper details on this Dan! I feel confident setting the machine up this way now.