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NesPi Needs More Power

Former Member

So i am doing the nespi project and have found that i need power to a usb hub and power to the pi. I only have installed one usb 3.0 port for power to come into the nes case. If i get this power supply --> https://www.amazon.com/Adapter-Portable ... wer+supply

 

Can i take two usb cables from ^^^this power supply from a usb splitter into a single usb cable then split it back out into two usb connections. Then have one end go to the pi and the other end go to the usb hub to power both devices.

 

Another possibility i have thought of is trying to bring more amps to the usb hub but i do not know it it can handle more power in and if that would allow it to output more power per port.

 

I would also greatly appreciate any other ideas on how to get power to both devices with only using one usb port to get power into the case.

 

Attached is the setup before the powered usb hub was added in to power the 4 controllers separate from the pi's power. And the back port is the single usb 3.0 port i have to bring power into the case.

 

Hopefully later i can get a pic of that to help with any questions on the setup.

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  • 0

    Your amazon link doesn't work for me.

     

    Generally speaking, if you have an USB "charger" with multiple outputs, it will simply wire them in parallel. It's quite expensive to make separate powersupplies for multiple outputs.

     

    Similarly, on the 'pi side everything will be connected together anyway. So using just one cable will work too.

     

    The weak spot is however the cable. Many cables are not meant to carry that much current, so they have such a high resistance, that the pi has problems with that. "borrowing" a cable from an USB-harddrive (possibly with two USB-A's) might help....

  • 0 in reply to rew

    Sorry for the bad link it was something like this  https://www.amazon.com/gp/product/B00HQY35SM/ref=ox_sc_sfl_title_7?ie=UTF8&psc=1&smid=A3RJNQO8PQ21MT

     

    So if the power runs in parallel then it would bottle neck for 30cm then go back out parallel?

     

    How would one cable work? I have tried bring in a 5v 3a power supply from the single usb port to the hub then plug in the pi and 2 controllers the hub and 2 controllers to the pi. I get the rainbow on the pi in the upper right hand corner so it seems it still getting under volted in the cable route. If i use the same 3a power supply with one cable straight to the pi with all 4 controllers on it then the pi will not even boot due to lack of power it seems.

     

    What kind of usb hard-drive cable do mean?

  • 0 in reply to Former Member

    Not saying that's a good one to buy, but to illustrate what I mean by harddisk-cable.

    https://www.alibaba.com/product-detail/USB-HDD-Hard-Disk-Drive-Case_256806340.html

     

    Oh, you have a hub and a bunch of devices in that box? How about powering the hub with the "BIG" cable and then having a "power only" cable from the hub to the pi?

  • 0

    i Tried that once and could not get enough power to the pi with a 5v 3 amp power supply.

     

    when i tested ^^^ this i had 3 amps coming  into the hub then 2 controllers in the hub and the pi on the hub. i then had 2 controllers off the pi and a jump drive. With all this plugged in the 3 amp power supply could not get enough power to it. I am going to try a cable similar to the link you posted but for usb only and hope a single usb cable wont bottleneck it to bad. Going this route it should have around 4 amps coming it. If i use a 24watt anker dual usb charger.

  • 0 in reply to Former Member

    AM wrote>>...i Tried that once [use a BIG cable] and could not get enough power to the pi with a 5v 3 amp power supply...

    USCDADNYC reply>>IDK (I Don't Know) if you are unfamiliar/adverse-to "Soldering/wiring" your own "Jerry-rig" solution. But if that picture (...134001.jpg) shows the HDMI and USB3.0 Receptacles AND the USB3.0 WILL BE USED FOR DC POWER ONLY. You might want to re-purpose the Pins in the USB3.0 Receptacle. BUT THIS IS DANGEROUS! Do a wiki on "USB" and check-out how many conductors are on a USB 3.0 Receptacle. You could re-purpose some of these wires to carry (separate USB Brick PSU's Voltages). On the inside you could split the USB3.0 wires back into separate USB Brick PSU Vdc voltages. TIP: if you have any (a) BAD/DEFECTIVE PC MoBo's (MoBo = Motherboards) and (b) a Dremel Tool. you can cut those stacked USB2.0 Ports OFF the MoBo And use these inside your Box. Then on the Outside you would have to cut-up a USB3.0 Cable and splice the appropriate wiring from two (or more) USB Brick PSU's. Think of your mounted USB3.0 Receptacle as a "FUNNEL" to get Power into your Box. If you do this, BE SURE to LABEL the USB3.0 Receptacle as "NON-STANDARD". Of course if any of your MI Force (MI = Mission Impossible) should get caught, the Secretary (USCDADNYC) will disavow any of your actions. Also keep in mind: Caveat Emptor. And Assumption of the Risks.

    To RW: Your referred to an alibaba site. Are along the Pacific Rim? (physically)

    USCDADNYC (NY NY USA)

     

     

  • 0 in reply to uscdadnyc

    RW is me? Call me "REW" on forums... :-)

    No, I'm in the Netherlands.... Western Europe.

    Some people don't dare buy stuff off ebay/aliexpress/alibaba because they got burned once. Fine.

     

    But with some care, you can get good stuff at great prices from there. Sometimes you get something you didn't expect. So somehow I got good probes for my multimeter. So I wanted them again for my other multimeters. I order them, and I get "scale models". They look exactly the same, just at 80% scale. In that case, I was lucky: the seller had mentioned the size of the product in the offer, and that corresponded to what I already had. Got an "oops sorry, here are the correct ones".

    Another thing people fall for is that they buy stuff that has specs that most people can't verify easily. Like batteries or powerbanks. There you are likely to get 10 times less capacity than claimed!
    But the leds I ordered yesterday are pretty good. How much current do most people push through a led? 20mA? They still glow visibly at 60nA. That's 300 thousand times less current than allowed. You need to look carefully to see that, but at 20uA they function great as indicator lights.

  • 0

    @ edward sadly i am not that skill with soldering so doing you mod would be pretty hard for me. Im kinda stuck at barely can solder skills and trying to keep every thing to plugable cables if possible.

  • 0

    REW wrote>>...They [Multimeter probes] look exactly the same, just at 80% scale...

    USCDADNYC>>80% scale of Banana Plugs (or Recessed-for Safety), Yes I think I saw smaller probes on a smaller-scale Analog Multimeter once. BTW WRT measuring those Low-currents on OLED's. which DMM do you use? I have a Portapow Premium USB+DC Power Monitor. (~ $40 USD=US Dollars). But IDK (I Don't Know [off-hand]) it's Current Measuring Resolution. If you should get a Portapow unit, I have a Great Graphic on how the Cables are wired. The supplied documentation was smaller than a Nano particle.

    USCDADNYC (NY NY USA)

  • 0 in reply to uscdadnyc

    When measuring a voltage, the measurement device will always draw a small current, which hopefully is negligible to the source being measured.  The input impedance of the meter needs to be as high as possible for this

     

    When measuring a current the measurement device will always introduce a small voltage in the current-path being measured, which hopefully is negligible to the system being measured.... The input impedance of the meter needs to be as low as possible for this...

     

    That voltage is called the "burden voltage".

     

    Now if we accept a burden voltage of 0.2V, and use a 10M shunt resistor, the meter will show 200mV full-scale for 20nA full scale current...... That 10M shunt resistor is builtin to most multimeters. (beware of the flukes... Those may have 17M input impedance, so the measurements are more difficult to evaluate on sight...).

     

    As 20nA was too little to see, I had to accept a burden voltage of 600mV for the measurement of 60nA. As long as you're aware of that, this is not much of a problem....