Raspberry pi usb power

What is the problem?

I have an Ender 3 Pro and a Raspberry PI 3B+ running octoprint with logitech camera connected to one of the serial ports. Pi is connected to the printer over serial.

The problem is that PI is giving power to the printer and the outcome is that the board and the LCD screen is powered and parts of the printer UI are working. This is happening no matter if the printer is turned on or off.

What did you already try to solve it?

I have tried to disable the power going off the USB ports of the PI but unfortunately if I want to do it I need to turn the power of all the ports off (which means that I am loosing the connectivity to the camera). I would like also to avoid masking with electrical tape the pin.

Is there something I can potentially do?

Thanks!

Well if you don't want to use tape on the 5V pin (btw why not :smiley:) you could search for an usb adaptor or cable without power lines and just data lines.

Also you could use a powered usb hub between pi and printer.

Hi!

Actually I think the easiest solution is to tape it for now :slight_smile:

I will look for an adapter though.

Thanks for the help!!!

You might also give my USBControl plugin a try to see if it will work for your Raspberry Pi 3B+.

I have just installed it and take a look!!!! Thanks!!!!!
Fast question: Why I cannot find it in the plugin manager. I installed it through the github link

You couldn't find it in the plugin manager list because I didn't publish it to the collection. I write a number of plugins but I don't always publish them since I don't want to support possibly a thousand users wanting assistance.

Yeah... I mean... Look at what can happen :rofl:

I'm SO antisocial it hurts.

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Keep the meme marathon under control please, this isn't an image board :wink:

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At the large USB end of the cable, I used a small drill bit, about the size of the USB connector etch width to 'cut' off the power lead on the connector. There happened to a hole in the connector shield that lined up with the etch to be cut. Maybe I was lucky, but the power pin then fell out of the connector, and it works well.

Does a powered USB hub correct the issue of power being sent to the printer and it receiving enough juice to keep the LCD and fan barely turning? I have just set up Octo Print on a Pi4 and connected it to my Ender 3 v2 and am having this issue. Just curious how a powered USB hub would fix this issue? Seems as if it would still have the same problem, no?

Good question - I guess it depends in the hub.
Most active hubs work also as passive hubs if you don't connect a power supply.
So they use the usb power of the host (your pi) in that case.

If you connect the power supply the hub should no longer draw any power from the host.

But what happens if you draw more power from the hub than it is able to deliver? Maybe it takes the rest from the pi.

In that case you could use the tape on the cable to the hub. Then only the power supply should be used.