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Prop Plug Rev E Problem — Parallax Forums

Prop Plug Rev E Problem

Hi friends,
I have two problems.
1-) I have a Prop Plug Rev E. It is sometimes works sometimes don't works. When I press to F7 in the Propeller Tool I get a message: No Propeller found on any serial port. Scanned COM7

2-) I designed and produced a Prop Plug for myself. I benefited the original Prop Plug Rev E Schmeatics.
I get the same error as in case 1. I attached the my schematic.

Looking forward to your help and advice. Have a nice day.

Comments

  • Hi @aguler

    Could be something related to the reset circuit on your target. Are you connecting to a stock or homemade module? How long are the connecting cables? Maybe post a photo, and in-case of a homemade board a schematic ?

    Changing C5 to 10nF will get you a longer reset pulse, which will help if you have certain conditions at your target. Even without seeing the whole picture, good chance that change will solve your issue, and it certainly won't hurt either way.

  • Hi @VonSzarvas
    I'm using my own P2-based custom board that I designed.
    I know this board works fine, because I can program itself with another prop plug I have.
    I am attaching the photo showing the cards and their connection types.
    Also i will try with 10nF cap.

  • VonSzarvasVonSzarvas Posts: 2,776
    edited 2022-08-30 11:50

    Looks like you have C18, R2 and maybe R1 on the P2 RESn pin signal? Extending the reset pulse with 10nF should be all you need to push past those and make the reset rock solid on your board.

    BTW.. That's a mean looking "propplug". Nice ! Is that 2nd USB socket for power ?

  • C18(100nF) and R2(10k) for reset circuit. 2nd USB socket for programming ESP32.
    BTW, I discovered something new. When I plugged my custom propplug to USB, the Red LED (D1) always ON.
    But Original Propplug doesn't. I wonder what is different in my own propplug?
    Did you review my schematic and original schematic? What is different?

  • I'm guessing you took those parts (c18/r2) from the P2-EVAL schematic ? C18 likely wouldn't be needed in your board, as you are programming by PropPlug. Essentially it would be adding a double time filter/delay. The coupling cap is typically used between an FTDI chip and the P2 (which is the case on the Eval board). However the PropPlug already has the circuitry built in. You could most likely remove your C18 to also resolve things. (Caveat- some assumptions made without seeing a schematic! Balance any advice here with your better judgement!). Also, assuming R2 is a 10K pullup to 3.3v, then you'd want to keep that.

    The LED thing might be down to your FT_Prog settings?

  • Hi @VonSzarvas
    I found out there is such a thing as FTDI_PROG 5 minutes before you commented. :)
    I programmed FTDI, and it worked.
    I am designing with FTDI products for the first time and I did not know that such programming existed.
    Thank you very much for spending your precious time for me. Have a nice day.

  • JRoarkJRoark Posts: 1,100

    I'm just going to pop-in here for jiff to say this: "NICE BOARD!". Once you get past the current problem, can I encourage you to start a new thread and brag on it a bit? Love to see stuff like this.

  • MicksterMickster Posts: 2,216
    edited 2022-08-30 19:15

    @JRoark said:
    I'm just going to pop-in here for jiff to say this: "NICE BOARD!". Once you get past the current problem, can I encourage you to start a new thread and brag on it a bit? Love to see stuff like this.

    :+1:

    Just in case:

    "brag on it a bit"

    Translation:
    Please tell us about your board :smile:

  • JRoarkJRoark Posts: 1,100

    @Mickster said:
    :+1:
    Just in case: "brag on it a bit"
    Translation: "Please tell us about your board" :smile:

    (laughing!) Yup. Nailed it.

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