11 Replies Latest reply on Nov 25, 2015 2:28 PM by anthonyprescott

    Portable power for Galileo

    philly

      Is it possible to create a battery pack to give the galileo portability?

        • 1. Re: Portable power for Galileo
          Clayton Hofrock

          It is absolutely possible, it just will not be very small, and it will need some electrical circuit to keep it from draining the battery too much.

           

          There is an Intel employee who is using the Galileo for a weather station. They have a solar cell to charge the battery (deep cycle marine battery, essentially a battery for a boat) and a circuit to power the system off if the voltage gets too low.

           

          I am not sure of how large of a battery you will need. It might be that the boat battery is way too big, but I am fairly sure the Galileo will not run very long off of a cell phone sized battery.

          • 2. Re: Portable power for Galileo
            DexoDan

            I just use a cell phone external battery pack.  Something like this Amazon.com: Yubi Power YP250ABLU 2500mAh Ultra Compact Lipstick Size Portable Power Bank Backup External Battery Charger… Hack a usb charging cable to wire it up to a connector that fits into the power jack on the Galileo.

            • 3. Re: Portable power for Galileo
              philly

              Portability is my bigger problem. It will be attached to a robot so the lighter the better but saw some examples which will last only 15 mins running a sketch? I am also worried about voltage frying the board.

              • 4. Re: Portable power for Galileo
                dferyance

                I also recommend a USB charging pack. I used one for my robot controller https://communities.intel.com/thread/51433 and was happy with the results. The nice thing is they have power management and charging built-in. I haven't tried fully draining mine but since it is intended to provide 5V output, I expect they will cut off on low voltage. They generally provide a good amount of current as they are intended for charging, but it is something to pay attention to. You also have a lot of options for sizes and capacities. You can connect 5V either to VIN or to the barrel jack connector.

                • 5. Re: Portable power for Galileo
                  intel_jassowski

                  Most of these charging packs have regulated 5v output, and will cut off when battery charge drops too low to support continued operation.  HOWEVER: once the board is forcibly shutdown, the lower current draw may drop enough for the battery pack to sustain 5v operation again. When this happens the board may try to reboot again, and possibly fail when the current draw exceeds the battery's reserve and the voltage drops again.  If this happens, it may do bad things to the boot-loader.

                  I have had a Galileo require a dediprog reflash after running on a 5v USB charging pack until drained.  While I cannot confirm that this was definitely the cause, if running on batteries you should definitely take measures to monitor your voltage status and shutdown gracefully when low voltage is detected... (which might actually be more difficult with a regulated supply).

                  • 6. Re: Portable power for Galileo
                    philly

                    These are excellent suggestions thank you very much. I am going to try 4 combined D cells and try to do a graceful shutdown in the event of a drop in voltage. @intel_jassowski is there any dependable method for achieving this?

                    • 7. Re: Portable power for Galileo
                      intel_jassowski

                      The simplest method would be to monitor the D-Cell voltage with one of the Galileo analog inputs and perform a graceful shutdown if the voltage drops below a certain threshold (the value would depend on your battery chemistry).  Note that even when shut down completely, I believe there still is some current draw.  If you are using rechargable batteries, you'll probably want to disconnect the batteries to keep them from a full depletion (which can damage/shorten the life of some rechargables).  Maybe send a quick email before the shutdown, or hook up a piezo speaker to a pwm output for an audio alert.

                       

                      Also: you need to be sure not to supply more than 5v to the 5v input on the Galileo.  4 D-Cells is nominally 6V and will require regulation.  You'll want to sense the D-Cell voltage on the battery side of the regulator -- which will also be higher than allowable for the analog inputs without a voltage divider.


                      • 8. Re: Portable power for Galileo
                        philly

                        Thanks for your help intel_jassowski. The batteries I have are 1.2V by 4. so I hope to stay between 4-5V. How can I measure the voltage using an analog input if the power is entered in via an AC-to-DC adapter? can I do a graceful shutdown from command line?

                        • 9. Re: Portable power for Galileo
                          doorleyr

                          Hi DexoDan. I had the same idea. I'm using a battery pack like this: HooToo Prism 12000mAh Power Bank: Amazon.co.uk: Electronics and a USB to barrel jack adapter like this: USB-A to 5.5mm / 2.1mm Barrel Jack Male DC 5v 2ft power charger connector cable | eBay

                           

                          However, when I turn on the battery, the "On" LED flickers off every so often so I think its not getting enough current. I think it may be because the cable cannot handle 2A of current. Can you elaborate a little on how you hacked a USB cable? It would be a great help.

                           

                          Thanks,

                          Ronan

                          • 10. Re: Portable power for Galileo
                            anthonyprescott

                            Hi intel_jassowski. It is fairly straightforward to monitor a pin and issue a system call to shutdown the Galileo Gen 2.  I can see the board powers off completely*.  That's great. 

                             

                            How would I power up the board again without unplugging and plugging power? (I have the POE module installed).  I can see the Edison breakout board has a power switch connect to the Quark PWRBTN, but can't see where I can get to that on my Galileo.  Admittedly, I haven't tried pressing the reset button (don't have the board handy at the moment).

                             

                            Would love to be able to do this.  It is not completely relevant to this thread, but I do want to know how to power back up the device (ie if battery voltage charged to appropriate level, I could have an external circuit drive the PWRBTN line low to power on the device.

                             

                            Your assistance is appreciated.  Thanks for your time in advance.

                             

                            *minus some current draw according to your post.

                            • 11. Re: Portable power for Galileo
                              anthonyprescott

                              bump - anyone?