7 Replies Latest reply on Feb 16, 2015 7:25 AM by JPMontero_Intel

    Repowering the Edison After Pushbutton Shutdown

    mweal

      I have my first custom carrier for the Edison back, and I am having an anomaly with power.  I am using usb and battery power. My power circuit is based off of the Edison breakout board circuit with the following changes:

      • power is sourced from the console USB port rather than the OTG port.
      • I have added a coulomb counter to the battery path
      • I have configured the charger to limit the usb draw to 500mA

       

      On the Edison breakout board if I power down the unit using the power button (8 second assertion) while on battery power, the unit will automatically power backup when I plug in the USB power source.  On my board if I do the same test I have to use the power button to get the Edsion to power back up.

       

      Any Ideas on what I could have done that make them operate differently?

        • 1. Re: Repowering the Edison After Pushbutton Shutdown
          JPMontero_Intel

          Hi mweal,

           

          I don’t understand your issue. Could you specify what the anomaly with power is? Did you modify the board to power the board from the console USB instead of the OTG?

          … the unit will automatically power backup when I plug in the USB power source.

          Did you mean when you unplug the USB power source the battery starts working?

           

          Also, keep in mind if you power the board from USB and battery simultaneously you might burn the board.

           

          Regards,
          JPMontero_Intel

          • 2. Re: Repowering the Edison After Pushbutton Shutdown
            mweal

             

            I don’t understand your issue. Could you specify what the anomaly with power is? 

            I have have a custom board I created based off the the Edison Breakout Board with the changes mentioned previously.  They operate differently.  On the breakout board if I power down the using using the push button power switch, the Edison will automatically power back up when I apply external power (not battery, ... via the usb otg port).  On my board doing the same thing (applying power in this case via the console port) does not power the Edison back up.  I was wondering what I could have done different that would cause this.

             

             

             

            Did you modify the board to power the board from the console USB instead of the OTG?

            Yes, basically I have done the equivalent of removing the TPS62133 power supply circuit, the diodes CR1,CR2, CR6,CR7 and connected VBUS_2 (the console power pin) to the input of BQ24074.

             

            Did you mean when you unplug the USB power source the battery starts working?

            No , I mean when the Eidson is powered down and under battery power, when I plug the usb power source in the Edison boots back up (in the case of the Edison break out board)

             

             

            Also, keep in mind if you power the board from USB and battery simultaneously you might burn the board.

            I think you are wrong here (but correct me If I am wrong).  The USB port supplies power to the BQ24074 battery charger, which then controls the distribution of power to v_sys and the charging of the battery on J2.

             

            And now the light goes on.....  Where you thinking I was applying battery power to the Edison via J21.  This is not the case, the battery is a li-ion battery connected to the battery charger via J2.

            • 3. Re: Repowering the Edison After Pushbutton Shutdown
              mweal

              After a little experimenting it looks like the difference between the two boards is that when power is applied to the Edison breakout board via the usb otg connector power is applied to the VBUS pin of the Edison.  On my board the VBUS pin id no connected.  By connecting the Edison VBUS to the power pin of my console USB connector via a 10K resistor I get the device to wake up the same way.

               

              Now I need to know if the VBUS wake up is design intent or some unplanned event that may disippear in the future.

              • 4. Re: Repowering the Edison After Pushbutton Shutdown
                Frederick Blais

                Hey mweal,

                 

                Is it possible for you to post some pictures of your custom board? Which software did you use to design it? Is it 2 or 4 layers?

                 

                I would like to get started soon to make my own board for the Edison with Diptrace. It would be interesting that people share their experience.

                • 5. Re: Repowering the Edison After Pushbutton Shutdown
                  JPMontero_Intel

                  HI mweal,

                   

                  Yes you are correct I got confused I thought USB were going to the same line. I thought the issue was due to the current limit that might not give the board enough current to the board. Could you attach the schematics of your board?

                   

                  Regards,
                  JPMontero_Intel

                  • 7. Re: Repowering the Edison After Pushbutton Shutdown
                    JPMontero_Intel

                    Hi mweal,

                     

                    I apologize for the delay in my response. Your schematic looks good, regarding your question on VBUS I believe it is part of the design so it needs to be connected as you mentioned above.

                     

                    Regards,
                    JPMontero_Intel