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Where can I find the complete circuit diagram for PIC pgrogrammer?

Discussion in 'Microcontrollers' started by thecritic, Sep 10, 2010.

  1. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    hi,
    Look at the 3 DATA line points, when you VERIFY a PIC, the PIC drives the DATA line, which if you used a 4069 would be held at an active High or Low by the program. This will cause problems.
    Use the correct chip types as specified in the circuit diagram.
     
  2. thecritic

    thecritic Member

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    O.K, I am going to switch back, then. ( I haven't taken the risk of connecting the programmer to the PC yet)
    I at first thought that CMOS, were superior than TTL s (higher Fan outs, Lower power cosumption and Higer price). So I thought that TTL was used just for the lower price as the other benefits aren't required.
    I am learning how I was wrong.
     
  3. thecritic

    thecritic Member

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    I don't think you were right here. I bought a brand new dm7406. Suplied just powers through 7805 (whose input is 13volts). It (7805) consumed damn 33mA at 13v. I drove a led through 1 of the gates. It (7805) consumed 45mA.The datasheet also lists 30mA as a typical supply current.
     
    Last edited: Sep 16, 2010
  4. dave

    Dave New Member

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  5. thecritic

    thecritic Member

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    I connected the programmer to the PC. The oshonsoft (http://www.oshonsoft.com/picprogparallelsetup.exe) programmer software seemed to work fine. When I enabled and disabled the Vdd/Vpp line by using the Hardware Check Freature of the software, the Leds responded correspondingly.When I programmed a simple program, It said, Chip Programmed. But When Verifying, it Said " Verification failed. Expected data 102A, Obtained data: 3fff." I even checked the PIC on breadboard, to see if it was programmed, but No.
    Anybody interested to say what might be at fault?
     
  6. 3v0

    3v0 Coop Build Coordinator Forum Supporter

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    Repeat that but check to see that VPP voltage is about 12.
     
  7. thecritic

    thecritic Member

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    Yes, It is 13.2 Volts.
     
    Last edited: Sep 16, 2010
  8. thecritic

    thecritic Member

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    How do I know if I have already damaged my PIC?
     
  9. 3v0

    3v0 Coop Build Coordinator Forum Supporter

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    That is why one should always buy at least two chips of the same type.

    Which PIC are you trying to program. VVP is not always the same and I would have to look at a datasheet in that it has been a while.

    In general PICs are tough little chips and they are hard but not impossible to ruin.
     
    Last edited: Sep 16, 2010
  10. thecritic

    thecritic Member

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    Tried with another chip, but no change.:(
    I read somewhere that a capacitor between Vss and PGC may solve the problem. Shall I try?
     
  11. Wp100

    Wp100 Active Member

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    Hi,

    Have you tested all the lines from the Software ? Vdd,Clock, Data as well as Mclre.
    You should see over 4v on the clock and data lines and 5v on the Vdd.

    You do not specify exactly what capacitor you are talking about - adding parts at random, particularly caps, will more than likely create more problems.
     
  12. thecritic

    thecritic Member

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    Yes I tested every (five) pins of the socket. Vdd, Clock (PGC), Data (PGD) are 4.8 to 4.95 Volts (when enabled through software). Vpp is 13.2 Volts. Vss is few milivolts i.e. effectively 0.

    I was taking about putting small cap (150pF) in between the PGC and Vss terminals of the socket. But I don't know how it will help or if at all.
     
    Last edited: Sep 16, 2010
  13. Wp100

    Wp100 Active Member

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    Hi,

    Well in that Picall circuit I have added a small cap and resistor to both C and D lines as recommended here. PIC Programmer for Windows - Help Index

    As for adding 150pf just to the C line ? - no reference ?

    You might be better getting hold of a pic chip that has already been successfully programed and seeing if you can Read that in via the programmer - at least that will show if the circuit is working in part.
    Would think someone at your college can help there ..
     
  14. thecritic

    thecritic Member

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    I don't think it will help.
    Well, I think the programmer can't write in the first place; because, a simple LED blinking program was written to the PIC, and then the PIC was tested in breadboard to see if it blinks the LED, but no.

    I am going to add the capacitors, nonetheless.
     
  15. thecritic

    thecritic Member

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    Tried that. But no success at all.:(
    One thing I want to mention
    1. i have connected the ground to only pin 25 of the parallel port. (18-25 are grounds)

    Should I be connecting to all?
     
  16. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    I have seen some parallel connectors having only 0V wires on pin 18, use an ohm meter to check continuity.
     
  17. thecritic

    thecritic Member

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    Are you aware that the software can control the LEDs through its Hardware check feature?
    Also, the software finishes programming a 210 byte simple Led blinking program in fraction of seconds , is this normal?
     
    Last edited: Sep 17, 2010
  18. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    Yes,
    I dont understand your reply.????
     
    Last edited: Sep 17, 2010
  19. thecritic

    thecritic Member

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    I thought that: if the "parallel port's Ground" wasn't connected to the "programmer's ground" then the software wouldn't have been able to control the LEDs.
    Anyway, I am ready to do anything.
     
  20. ericgibbs

    ericgibbs Well-Known Member Most Helpful Member

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    ok,
    If you feel that the paraport of your PC maybe damaged, download this 'paraport' link and check each pin used by the prommer circuit.

    http://www.electro-tech-online.com/blogs/ericgibbs/122-pc-parallel-port-using-vb5.html

    Run the paraport2.exe program

    EDIT:
    Post your program hex file that you want to program a PIC with. [ also PIC type], I will double check that for you.
     
    Last edited: Sep 17, 2010
  21. thecritic

    thecritic Member

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    On the contrary I feel the parallel-port is is working fine. Thats why the software is able to control the LEDs. Sorry for creating misunderstandings.
    Thanks for that. I have attached the hex file and the C file of the LED blinking program. There is a little input and conditional statement too!
    I am using PIC16f877A.
     

    Attached Files:

    Last edited: Sep 17, 2010

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