Program and Circuit will not run WITHOUT an FTDI...


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  1. #1
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    Default Program and Circuit will not run WITHOUT an FTDI...

    ...and if the FTDI is removed, the PIC fries, and becomes unusable.

    The Background: I'm an senior taking a mechatronics course for the first time. Our project was to build a device that would count (using two 7-segment displays) from 0 to 99, with a toggle switch that would make the display start counting down from wherever it is. The circuit also would need a reset button to start the program from the beginning.

    Hardware:

    PIC - 18F2550, bootloaded ( /1 (4 MHz), /2 (/1), 96 MHz PLL/2, HS)
    FTDI - FT232R Breakout
    5 V Voltage Regulator

    Now, If I had to guess, I'd say it was being caused by the FTDI being grounded funny, or its DTR not being hooked up properly. BUT! I'm sure my current setup is correct (I will post pictures if that'll help). The DTR goes to the PIC's MCLR, which splits off to +5 V, and a switch that goes to ground. Also, the FTDI is grounded in and of itself. There are no shorts anywhere on the board that my multimeter can find, and both sides of the PIC are grounded and powered.

    The program runs just fine, but if I turn the power off, unplug the FTDI, and turn the power back on, the circuit doesn't do anything. And if I run the program with the FTDI still in, and unplug the FTDI, the PIC not only doesn't work, but also refuses to work ever again, even if I bootload it again.

    Right now, it's less about the grade (what we've done will land us a solid B), and more about being curious. Anyone know what the problem is? Thank you in advance!

  2. #2
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    Hi, Dinona

    Without a scheme ( you posted in the schematics section ... remember. ), and the PIC program ... no chance for you to get the least usable answer ...

    Nobody here knows about your galaxy

    Alain
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
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    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
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  3. #3
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    Quote Originally Posted by Acetronics View Post
    Hi, Dinona

    Without a scheme ( you posted in the schematics section ... remember. ), and the PIC program ... no chance for you to get the least usable answer ...
    Alain
    Then let there be pictures! And code!

    WARNING! What you are about to see and read was design by someone who only had a vague idea of what was going on. Look at your own mental risk. Though, I can assure you that there are no obvious shorts (resistors touching, ect).

    http://tinypic.com/r/20pekhz/7
    Attached Files Attached Files

  4. #4
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    Quote Originally Posted by Dinona View Post
    Then let there be pictures! And code!

    WARNING! What you are about to see and read was design by someone who only had a vague idea of what was going on. Look at your own mental risk. Though, I can assure you that there are no obvious shorts (resistors touching, ect).

    http://tinypic.com/r/20pekhz/7
    Try to be serious : how do you hope us to verify if your connections are correct ???

    [Humour ON]

    a FTDI module with an USB equipped Chip ... looks funny, no ???

    [Humour OFF]

    Alain
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************

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