14 Replies Latest reply on Dec 22, 2019 11:08 AM by EvPa_264126

    PSoC 5LP custom board



      I followed the schematics of the PSoC 5LP prototyping kit and built my own custom board (smaller form factor). Shown below is the schematic I made with the original schematic as the reference




      I am using the kitprog from the official prototyping kit to program my custom board. I am not able to program it. Even though the kitprog shows in my device manager (shown below) I can't select a target device in the PSoC creator. I am able to upgrade firmware of kitprog using PSoC programmer. Whenever I try to program using the PSoC creator I get the "Port acquire failed" error. Images are shown below for reference. What is the cause of this issue? Please help me fix it.






        • 1. Re: PSoC 5LP custom board



          As far as I briefly saw your schematic, "I" could not find any problems.


          From what you wrote, my best guess is  that the connections of 5 signals






          may not be perfect.


          I could imagine a couple of reasons

          (1) The connection of 5pins is opposit, something like [1..5] vs [5..1]

          (2) One or more wires between KitProg and your board is broken


          (1) It is my shame but I often do this mistake. You might have a chance, too.

          (2) Considering your level, this is more likely, please use a tester to check if each line is intact.

              Note: Checking R between VDD and GND may be the first to test.


          And there also is following AN in case you have not got it.

          AN61290 - PSoC 3 and PSoC 5LP Hardware Design Considerations




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          • 2. Re: PSoC 5LP custom board


            Thanks for the quick reply.


            I did make sure the pin connections are properly in order. Even I tend to mess it up frequently.

            The wires between kitprog and the board are intact. I even tested the kitprog after breaking it off just to make sure I was still able to program using that.


            There is no short between VDD and GND, I am seeing very high resistance between the two. However, while I was checking voltages I realized that the voltage between XRES and ground was around 2-3 V rather than 5V as measured on the CY8CKIT-059. So I thought it was because I left it floating. Even on their dev board R19 and C17 (shown below) was not put in, it was empty. But they still managed to get 5V across XRES and GND. So I put those components externally and tested again. The voltage was still around 2-3V. Could this be a reason for it not working? What could be the cause of not seeing 5V across XRES and GND?





            • 3. Re: PSoC 5LP custom board



              I think that I read in the TRM or Hardware Design Considerations that XRES is internally pulled-up.

              So we don't need an external pull-up.


              But your reading voltage does not seem to be pulled-up.

              Off my head a couple of possibilities...

              (1) VDD is not provided to the device

              (2) XRES is not connected to the device

              (well, one more)

              (3) The device is broken somehow.


              Can you apply tester between PSoC's XRES and Board's connector?

              As well as Device's VDD and Board's VDD, Device's GND and Board's GND?

              I hope that if the device is properly powered, we should see higher voltage in XRES.



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              • 4. Re: PSoC 5LP custom board



                I don't know your schematic capture tool.

                In the bottom right corner of your schematic, it shows "9*5".  Does this mean there are 5 connections to ground starting from pin 9?  This may have inadvertently connected pin 6 to ground (should be floating as correctly shown on schematic bottom left corner).  Could this be an issue?


                A similar schematic question at top right corner for VCCD?  What is "26*2" actually doing?


                You don't mention it, but do you see 5V on other 5LP pins, like VDD?


                How are you powering this circuit for programming?  Through Kitprog connection?


                Can you install the 4.7k Ohm pullup resistor on XRES (I generally use a 56k Ohm resistor) and power up the circuit without Kitprog connected.  If you don't see 5V on XRES, then there's something wrong with the pcb, the soldering, wrong 5LP pinout, etc.


                If you have an un-populated pcb, check that all 5V pads are connected together using 1 pad as the reference point.  Do the same for all ground connections using 1 ground pad as the reference point.


                Keep the Kitprog wire length between 5cm to 10cm.  Any longer and you'll have signal quality problems (which lead to not acquiring the device).


                Have you re-tested Kitprog on KIT-059 to know it's still working properly?


                Hope you find something and let us know your solution.



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                • 5. Re: PSoC 5LP custom board


                  It is hard to place a tester at those pins because of the chip package.

                  At this point I am inclined to think that it is a soldering issue. I soldered this without the help of a stencil. Maybe some of the pins shorted and that's why I am seeing that lower voltage on XRES. I will get back after I get a new board soldered with the help of a stencil.

                  • 6. Re: PSoC 5LP custom board


                    I am using EagleCAD to build the schematics and PCB. "26*2" and "9*5" are just saying that Pin 26 is repeated twice in that chip and Pin 9 is repeated 5 times. The connections are all fine.


                    I am powering the chip using kitprog connections. Yes I do see 5V on the other pins. Yeah, I think the issue is soldering like I mentioned above, due to the lack of stencil. Yes true, I didn't want cables in my circuit, so the kitprog sits directly on the PCB with suitable headers. I did test the kitprog after breaking it off to make sure it was working. I will get back once I do the resoldering with the help of a stencil.

                    • 7. Re: PSoC 5LP custom board


                      I got a stencil and got it soldered. Still no luck I am out of ideas. Any suggestions? PFA the schematic and board file created in EagleCAD. Please let me know if something is wrong.

                      • 8. Re: PSoC 5LP custom board

                        the VCCA pin has 1.71 V to 1.89 V and a capacitor  >= 1.0 uF?

                        • 9. Re: PSoC 5LP custom board

                          In the original schematic VCCA pin is directly grounded through a 1uF capacitor (shown below). That is exactly what I did. So I see a 0V between VCCA and GND


                          • 10. Re: PSoC 5LP custom board

                            it seems the presence of this voltage is a prerequisite. please look

                            PSoC® 5LP: CY8C58LP Family Datasheet: Programmable System-on-Chip (PSoC®).pdf   page  27

                            I don’t remember the details.

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                            • 11. Re: PSoC 5LP custom board

                              That is the case when PSoC5 is powered in the externally regulated mode. I am using the internally regulated mode where I am supplying 5V to the VDDx pins which is what they have recommended.

                              • 12. Re: PSoC 5LP custom board

                                yes, but VCCA and VCCD are internal regulators and cannot have 0V on them   (see page 12)

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                                • 13. Re: PSoC 5LP custom board


                                  Yes you are absolutely right. They shouldn't have been 0V. I took a very close look at the board file generated by EagleCAD and realized that even though the schematic was absolutely fine, the board file was somehow missing 6 tracks. And those were the tracks which were supposed to connect to connect VDDA, VDDD and the 4 VDDIO pins to 5V !! Once I fixed them, it started working!! This is very wierd, EagleCAD never did this kind of a mistake before.


                                  Anyways it's fixed now and thanks a lot everyone, for all your quick, useful and helpful comments

                                  • 14. Re: PSoC 5LP custom board

                                    glad that helped, good luck.