6 Replies Latest reply on Dec 22, 2017 9:29 AM by ScottYanke

    External Power on CY8CKIT-059

    ScottYanke

      I have several CY8CKIT-059 boards that I have been trying to use with external power, other than that supplied through the USB cable connected to the KitProg.  I need to use a heftier power supply than what can be supplied through the KitProg or the USB cable at the far end of the board.  It's because of the number and type of devices I have attached to the board, mainly (4x20 LCD display w/backlight, DS3231 RTC module, ENC28J60 chip for an ethernet connection, for now).  The attached devices really suck too much juice for me to run through the USB connection.

       

      What I am running into is a problem with programming through the KitProg, while powering the board externally.  I know about removing D1 on the KitProg board to prevent power from backfeeding to the KitProg, but that introduced a new problem.  Once I remove D1, I can't program the 5LP at all, or even see it through the Bridge Control Program.  That's been also tried with a second USB cable connected to the far end of the board, which does power it up.  If I put D1 back, then it works, but with D1 out, it won't program.

       

      I've tried running 5V power to VDD on the main board.  I've tried through the target USB connector, per section 4.2.3 of the manual.  I suppose that I could just power all of the external devices using external power, but I'm not thrilled with the idea that power might backfeed through the IO pins.

       

      I'm open to suggestion.

       

      Again, if D1 is removed then I can't do diddly, programming-wise.  I have NOT snapped the boards apart, mostly because I don't want to track down programming boards (I tend to lose them until I find 6 at a time, just after ordering more)

       

      If I supply power through the target USB connector, the 5LP chip seems to get a bit warm, which also makes me nervous.  And that's with D1 removed.

       

      Scott.

        • 1. Re: External Power on CY8CKIT-059
          srds

          Hi Scott,

           

          Use can use a MiniProg3 to program/debug the PSoC 5LP device when the CY8CKIT-059 is powered through external supply.

           

          If your application does not require the kit to be always connect to a PC, just disconnect the kit from the PC and apply external power. You don't need to remove D1 for that.

          • 2. Re: External Power on CY8CKIT-059
            ScottYanke

            srds,

            Unfortunately, I don't have a MiniProg3.

             

            I am wondering how others have managed to make this (removing D1) work for them.  Some other postings have talked about how the KitProg detects the voltage, but it really doesn't for me.  Without the D1 connection, Windoze doesn't even see the KitProg (tried on multiple machines).  I can put D1 back, but am concerned about the multiple voltage sources.

             

            Scott

            • 3. Re: External Power on CY8CKIT-059
              srds

              Interesting! Hopefully no other components on the board affected/damaged while removing the D1.

              In your case, does KitProg work just by populating D1 back? Disconnect all external components (display, RTC module, ethernet chip, etc.) and check the behavior once (programming through KitProg just with prototyping board and external power).

              • 4. Re: External Power on CY8CKIT-059
                ScottYanke

                Putting D1 back does work, although it took a few tries with PSoC Programmer to convince it to be recognized.  After putting D1 in place, it kept coming up as KitProg/1 until half a dozen tries with switching it back and forth to CMSIS mode.  After that it behaved.  I really do mean "KitProg/1", without the full serial number.  Apparently the 5LP on the KitProg board falls back to that number if it can't read the prototyping board.

                 

                I guess part of my question is - Why remove D1 from the KitProg board, when removing R20 from the prototyping board and using a jumper on J4 seems to make more sense (to me, anyway).  From the schematics, that should work, but it doesn't either.  Even removing the jumper on J4 (after taking out R20) puts it into CMSIS mode.  After putting the jumper back in and holding the reset for 6 seconds it will return to KitProg mode.

                 

                For now I will probably leave D1 (and R20) in place, and hope that everything goes ok.  I'm doing this on a breadboard and do not want to keep pulling the prototyping board out for programming.  The programming part is happening often as I am working out all of the details on making sure my i2c and SPI signals are correct, and as I alter my TCP/IP protocol.

                 

                If anyone else has experience with using external power with this PSoC 5LP prototyping board (or the PSoC 4 boards) I would love to hear from you.  In the meantime, I will be adding an SD card to the setup so I can do data logging.

                • 5. Re: External Power on CY8CKIT-059
                  user_159482

                  Hi Scott,

                   

                  I am running my KIT-059 on a separate 3.3v supply.

                  The changes I made were:

                  1  Break the Kit Prog from the Target

                  2  Remove D1 from the Kit Prog board.

                  3  Remove D2 from the Target board.

                  4  Connect up the external 3.3v supply.

                  5  Add 5 Pin headers to both boards and connect via a 5 wire cable via crimp socket shell.

                   

                  Works well for me.

                  Ensure that Vtarg is available on the Kit Prog board as it is needed for voltage level sensing.

                  You say you have a number if kits, so, go break one apart and see what happens.

                   

                  Good luck,

                   

                  Noel Diviney.

                  • 6. Re: External Power on CY8CKIT-059
                    ScottYanke

                    I finally decided just to use the diodes as-is, mostly because for now I'm just doing this on a breadboard.  When I get to the point where I'll need just the prototyping board only I'll snap off the KitProg.  Getting power through VDD or the USB connection is working, and I'm minimizing the amount of time that the KitProg board is connected to a PC.

                    It would be helpful if the documentation had a bit more about using this with external power, but I understand that this is just a prototyping board, and that probably doesn't come up for a lot of people.