30 Replies Latest reply on Dec 3, 2014 11:25 AM by jdubosejr

    USB Hub ?

    jdubosejr

      Hi, I'm using model B+ raspberry pi. Do I need to use a USB hub to have keyboard and mouse control? Nothing happens when I plug them directly into the on board USB sockets.Thus I'm not able to select the operating system.

        • Re: USB Hub ?
          lui_gough

          A hub is not strictly necessary - you only need one if you wish to connect more peripherals than the Raspberry Pi can power (i.e. power hungry hard drives) or more peripherals than the Raspberry Pi's board can handle.

           

          Any USB Human Input Device class compliant keyboard and mouse should function properly directly connected to the Raspberry Pi. Probably try plugging jiggling the connector a little in case it's a contact issue. Otherwise, another possible cause is a weak power supply which means the downstream keyboard and mouse aren't receiving enough voltage to operate correctly. Otherwise, do try another set of keyboard and mouse to see if it makes a difference.

           

          I hope you are using the latest Raspbian image from Raspberry Pi Foundation's website, as the B+ contains power management for the USB ports including a soft-start feature which might not operate under an older image built before the B+ came onto the market (which can explain a lack of power at the USB ports as well).

           

          Good luck!

          1 of 1 people found this helpful
            • Re: USB Hub ?
              clem57

              Agreed.

              I had same problem and put on a hub with the keyboard and mouse worked then! This means your power supply to the Pi is under 700mA probably. Try it on one with around 1000mA for best results.

               

              Clem

                • Re: USB Hub ?
                  jdubosejr

                  Hi,

                  Sounds like a plan. I'll go for a USB Hub. Any recommenced brand or model?

                  John

                    • Re: USB Hub ?
                      clem57

                      Just for testing

                       

                      Plug in the mouse only and boot up Pi.

                      Let me know if that works.

                       

                      Thanks

                      Clem

                        • Re: USB Hub ?
                          jdubosejr

                          Hi Clem,

                          I tried plugging in the mouse only as well as the keyboard and the WIPI only. And got the same results. No controls. So I decide to order the usb hub from element14. I'll let you know if it works or not as soon as get and test it.

                           

                          Regards,

                          John

                            • Re: USB Hub ?
                              clem57

                              I am afraid to say this, but the USB ports are either shorted/not connected to the board. Look carefully under the USB connector and see if 2 rows of 4 points are soldered on your board. If you have a case, remove RPi from it also. Be careful when testing this by putting the board on static bag and not touching anything on the board without touching true GND first!

                               

                              Clem

                                • Re: USB Hub ?
                                  Cory Chapey

                                  That is what I was saying for if nothing else worked.

                                  If the USB's have a bad solder connection or something similar, it is an easy fix however if that is not the case, John may need to look into getting a replacement from the company in which it was purchased.

                                  • Re: USB Hub ?
                                    jdubosejr

                                    Hi Clem,

                                    I took a good like at the board with an eye piece and didn't see any solder shorts or cold joints. So I'll test it again when I get the usb hud. By the way when I power up the green LED comes on then goes off and the red LED stays on. Is that suppose to happen?

                                     

                                    Regards,

                                    John

                                      • Re: USB Hub ?
                                        lui_gough

                                        The green LED indicates SD card access, so it's normal for it to come on, go off and flicker like mad while the booting process takes place.

                                         

                                        The red LED indicates the presence of power.

                                          • Re: USB Hub ?
                                            jdubosejr

                                            Thanks Lui,

                                             

                                            I made a few voltage measurement at the USB plugin on the pi and found nothing their (0.0v). How else will the keyboard, mouse and wipi get power to operate?

                                             

                                            John

                                              • Re: USB Hub ?
                                                lui_gough

                                                If the board is operating but the USB ports are not getting power, this is likely because of the soft start circuitry which is new to the Model B+. This was an additional power management feature, which switches the power to the ports sequentially in a manner such that plugging in USB devices when the Raspberry Pi is on does not cause it to brown out and reboot. Unfortunately this meant that older images with kernels that did not understand this feature may have problems providing USB port to the ports.

                                                 

                                                Your NOOBS card may have an older version of operating system installed on it which is not ready for working with the B+. I suggest you either download and install a new version of NOOBS from the Raspberry Pi foundation's website (as I suggested in the first posting) or directly download an image for the distribution of your choice (e.g. Raspbian, Raspbmc, OpenELEC, etc) and write the image to your microSD card.

                                                 

                                                If you still do not get power to the USB ports' solder points on the PCB, then you may have a defective board that needs to be replaced.

                                            • Re: USB Hub ?
                                              clem57

                                              When you get a powered hub, most likely the RPi will power up like mine does given you have a recent revision. If this works, the cable could be the problem. If you have a multimeter you can check the voltage after the cable as well as check the amperage...

                                               

                                              Clem

                                            • Re: USB Hub ?
                                              jdubosejr

                                              Clem,

                                              The board looks good, solder connection OK, no cold joints,etc.

                                               

                                              John

                                    • Re: USB Hub ?
                                      jdubosejr

                                      Hi Lui,

                                      I try using a different key board and mouse.

                                      Thank you

                                      John

                                      • Re: USB Hub ?
                                        jdubosejr

                                        Hi,

                                        I did try changing key a board and a different mouse. And got the same results,No movement of the prompt. Still can't access the operating systems.I'm thinking not enough drive current. I'm using the recommended power adapter, 5v, 2A. I don't want to buy a USB hub and fine out that it won't work either. 

                                        John

                                          • Re: USB Hub ?
                                            lui_gough

                                            Are you using the latest version of Raspbian from the Raspberry Pi foundation's website, or at least a recent image that includes support for the USB soft start mechanism on the B+ model?

                                             

                                            Do your keyboard lights come on and your mouse (if optical) light up or do they remain dark? Have you checked that the USB connections are firmly pushed in all the way? Have you tried plugging and unplugging the keyboard and mouse after it has booted? If everything is working, that should bring it to detect the peripherals.

                                            • Re: USB Hub ?
                                              Cory Chapey

                                              If your using a power adapter with 2A, I couldn't see it being an issue with the current, as 2A should be plenty enough for using a keyboard/ mouse and then some.

                                              Might I suggest trying different USB ports for the Keyboard and Mouse if you have not already. I would also suggest trying out something else in USB ports as it may be an issue with the ports themselves. Other than this, I would go with Gough's suggestion and make sure that you are using the latest version of Raspbian directly from the RPI's Website or a recent image that includes support for the USB soft start mechanism.

                                                • Re: USB Hub ?
                                                  jdubosejr

                                                  Hi Cory,

                                                   

                                                  Yes, I try using different keyboards and mouses. And the same results,no action from either. I'm using the recommended pre-installed Noobs for the pi with a choice of six operating systems. Just not able to choose either one of them.

                                                  So decided to get the USB Hub from element14. Once I get and test it I'll be in touch.

                                                   

                                                  Regards,

                                                  John

                                            • Re: USB Hub ?
                                              John Beetem

                                              I suggest checking for power problems, since an iffy power supply is the most common cause of RasPi issues: R-Pi Troubleshooting - eLinux.org

                                               

                                              It sounds like your power supply is fine, which means the problem may be the Micro USB cable that connects your power supply to RasPi: On the RPi usb power cable - eLinux.org

                                               

                                              Micro USB cables sometimes have very thin wires that cause an excessive voltage drop. peteroakes has an excellent 'blog on the subject: Raspberry PI:- USB power cables, crashing and other problems