Programmer G840 with Pic16f877a

Discussion in 'Embedded Systems and Microcontrollers' started by Saadyousuf, May 19, 2015.

  1. Saadyousuf

    Thread Starter New Member

    May 19, 2015
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    i am unable to program PIC16F877A and PIC 18F2550 please help needed .

    Also the configration bits of PIC16F877A are not able to change dont know why?

    G840 uses encrypt function to program bits....
    need help
    anything i need to know?
    is it reprogrammabale.???
     
  2. JohnInTX

    Moderator

    Jun 26, 2012
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    Is it this programmer?
    If so, the 877A is in the G840 device list (download) BUT searching on 16F877A on the site gets this, which implies that you need a VSpeed model??

    The 18F2550 is NOT in the supported parts list for the G840. Searching on 18F2550 gets this.

    It may be that you need to upgrade firmware in the G840 to support the 'F877A but you might be out of luck for the 18F2550.

    That said, a programmer that conforms to Microchip's programming specification for the F877A and F2550 should be able to re-program the chip including the configuration bits. It WON'T be able to read and duplicate a code protected chip. You might consider using a programmer made by Microchip.

    Are you trying to program by loading a .HEX file to the programmer?
     
    Last edited: May 19, 2015
  3. Saadyousuf

    Thread Starter New Member

    May 19, 2015
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    yes ia m trying to load a hex file
     
  4. Saadyousuf

    Thread Starter New Member

    May 19, 2015
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    0
    are these pics only one time programmable??
     
  5. JohnInTX

    Moderator

    Jun 26, 2012
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    Yes, you should be able to reprogram a code-protected chip from a .HEX file.

    In this document, the 16F877A is listed but the the 18F2550 is not.

    I posted the links to the programming specs above. Sometimes a non Microchip programmer can have problems. A good next step would be to contact technical support for the G840.

    Good luck.
     
  6. Saadyousuf

    Thread Starter New Member

    May 19, 2015
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    can these programmers be hard factory set via circuit?
     
  7. JohnInTX

    Moderator

    Jun 26, 2012
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    I am not sure what you mean by that.

    Answering your PM question:
    If you are programming out of circuit I would recommend Microchip's PM3 programmer with the adapter for your chips. The PM3 has an SD card slot that can store images to allow programming without a PC.
    It's preferred to program in circuit using ICSP (In Circuit Serial Programming). This requires a header on the PCB and some connections to the chip which can be shared with other IO. ICSP is supported by all of the Microchip programmers (including PM3) and debuggers (RealIce, PICKit 3, ICD3 etc). PICKit 3 also has a load and go capability.

    Microchip has some approved third party programmers by CCS and others which also support load and go. These can store several different images at once.

    All of these are available on Microchip Direct.

    Personally, I would stick with genuine Microchip or at least a Microchip-approved programmer. These have the best chance of reliable operation as well as regular updates for new chips. There are lots of cases where 3rd party 'universal' programmers that use a bunch of software controlled pin drivers have problems programming Microchip devices.

    Good luck
     
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