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I currently have a Raspberry Pi 2 B that I am trying to run off of a 2.5A 5V powered USB hub, while also having my peripherals off of that hub. I have the output of the hub to the regular Pi USB slot, and one of the inputs of the hub to the micro-USB power of the Pi. The problem is, the Pi will startup and lights will turn on for about 3 seconds before it shuts down, and starts all over again. I even went so far to snip the two data lines of the USB from the hub to power on the Pi, as well as ground, just in case of a grounding loop. Even with that, it does the same thing. If I don't have the hub output connected to the Pi USB, but still have the hub to the micro-USB power connected, it works just fine, but the moment I plug the hub output into the Pi, it shuts down. Does anyone have a solution for this? I have checked other topics, but nothing really covers what exactly is happening here. I am running OSMC if that matters.

  • I'm not quite sure what you are saying. You have a powered hub. You are feeding the microUSB power socket of the Pi from the hub? That should work. A reboot is a sign that the Pi is starved of power. Presumably when the other peripherals connected to the hub start taking power, or possibly when the Pi switches the hub on. – joan Jul 10 '15 at 11:09
  • Sorry for the confusion, yes that is correct. The funny thing is it still reboots even without any peripherals connected. – jordanryle Jul 10 '15 at 20:07
  • I am using thinkgeek.com/product/e2d2 which works well but is out of stock. you can try vendors that cater to rpi such as adafruit, but I have not found any reliable criterion to check this behavior other than to check. some do, some do not. – hildred Jul 12 '15 at 22:42
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I had this exact problem a while ago. Turned out it was a faulty $1 micro USB power cable. The cable does work fine for charging and syncing a handphone, but for some reason it doesn't supply enough juice to the raspberry. Other cables - the $2 ones - mostly don't give me any issues.

  • This just came up in my mind: You tried to cut the data cables out of your link between the hub and pi-powerconnector. How about cutting the power between the pi-usb and the hub? Just an idea but maybe worth a shot.
  • Thank you for your comment. The cable actually seems pretty decent quality: Amazon Basics, was about $5. As for cutting the power, I don't think that would work as then nothing at all would be going to the Pi (USB pins are GND, Data+, Data-, V+, though maybe not exactly in that order as I don't remember off the top of my head, and I have cut the two Datas and the GND.) – jordanryle Jul 10 '15 at 20:09
  • Does an external-powered usb-hub still requires GND and V+ coming from the host? I don't know. If it doesn't, this might be a solution. An alternative solution might be to split the power line directly from the power adaptor cable. – EDP Jul 11 '15 at 8:38
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There are some USB hubs with active power management that when they are plugged into a computer try to negotiate power consumption with every device, so they cut out the power to every device to start plugin events. These hubs (which are otherwise very nice hubs and work fine for every other use) will not work to power the RPI and act as a hub for it at the same time. the two workarounds are to add a really big capacitor (or battery) to the RPI so that it will function through this power interruption, or to steel power from the hub's power supply instead of the hub. It would probably be easier to just use a cheaper hub.

  • Ah, that makes sense. I am currently using a cheap (~$10) Amazon Basics powered hub, do you have a recommendation for a hub that might work? Or maybe some key words I should look for when searching for a hub? – jordanryle Jul 12 '15 at 22:29

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