+ Post New Thread
Results 1 to 7 of 7
  1. #1
    Member level 5
    Points: 1,901, Level: 10
    Achievements:
    7 years registered

    Join Date
    Jan 2011
    Location
    Montpellier FRANCE
    Posts
    81
    Helped
    11 / 11
    Points
    1,901
    Level
    10

    Problem to connect with USB self power to a PIC18F4550

    Hi,

    One of my studend has made a board to drive stepper motors.
    The problem is that, the PC could not communicate with the PIC18F4550 in self power mode.
    We use the PICDEM FS USB framework (HID custom demo modified software

    The student has made a small board with an another PIC18F4550 in bus powered mode and it works.

    We have verify the hardware, there no ground problem and the VUSB capacitor is on the board.

    Could you please help us and give to us some ideas for investigate.

    Thank you
    Jose Miguel

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 3
    Points: 4,828, Level: 16
    papunblg's Avatar
    Join Date
    Oct 2010
    Location
    Kolkata India
    Posts
    726
    Helped
    172 / 172
    Points
    4,828
    Level
    16
    Blog Entries
    9

    Re: Problem to connect with USB self power to a PIC18F4550

    Sir,
    You have not specify the actual problem.
    For example:-
    1. Using USB connection, D7 Power LED is on or not?
    2. Power LED is lit, but the system does not recognize the board.
    3.The board is functioning, but has stopped communicating with the Demo Tool.
    etc.
    Normally, the PICDEM FS USB board behaves by default as a bus-powered device. If it is connected to a functioning USB portThere are some Common issues with the PICDEM FS USB demonstration board and it is discussed in chapter 6 of The PICDEM™ FS USB DEMONSTRATION BOARD USER’S GUIDE.
    Also see
    PC USB Host to a PIC HID Interfacing - Development by Example: Hardware and Protocol Stack.: Silicon Devices (UK) Limited: Evaluation Cards - PIC Micro Controller USB HID Device with Interface to Host PC GUI
    Last edited by papunblg; 10th February 2012 at 15:31.
    Rajsekhar Nag
    -------------..--------
    Knowledge Grows When Shared


    1 members found this post helpful.

  3. #3
    Administrator
    Points: 69,512, Level: 64
    Achievements:
    Created Album pictures Created Blog entry 7 years registered
    bigdogguru's Avatar
    Join Date
    Mar 2010
    Location
    Southwest, USA
    Posts
    9,832
    Helped
    2358 / 2358
    Points
    69,512
    Level
    64
    Blog Entries
    4

    Re: Problem to connect with USB self power to a PIC18F4550

    Quote Originally Posted by joseMiguel View Post
    One of my studend has made a board to drive stepper motors.
    The problem is that, the PC could not communicate with the PIC18F4550 in self power mode.
    We use the PICDEM FS USB framework (HID custom demo modified software

    The student has made a small board with an another PIC18F4550 in bus powered mode and it works.
    Can you post the schematic of the design? And code of the test application?

    BigDog


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  4. #4
    Newbie level 3
    Points: 181, Level: 2

    Join Date
    Feb 2012
    Posts
    3
    Helped
    0 / 0
    Points
    181
    Level
    2

    Re: Problem to connect with USB self power to a PIC18F4550

    hi all, i am the student of jose miguel who meet the problem to the device detection.

    describe of the problem:

    I work with the framework of microchip USB CUSTOM DEVICE, the USB POWER SENSE I/O is realize on RB4 on my board, the capacitor of 470nF on Vusb is good, we have controlled all the ground= no problem.

    In HardwareProfile i have defined :

    //The PICDEM FS USB Demo Board platform supports the USE_SELF_POWER_SENSE_IO
    //and USE_USB_BUS_SENSE_IO features. Uncomment the below line(s) if
    //it is desireable to use one or both of the features.


    #define USE_SELF_POWER_SENSE_IO
    #define tris_self_power TRISBbits.TRISB4 // Input
    #if defined(USE_SELF_POWER_SENSE_IO)
    #define self_power PORTBbits.RB4
    #else
    #define self_power 1
    #endif

    In the main.c, i have just remove the subroutines:

    void BlinkUSBStatus(void);
    BOOL Switch2IsPressed(void);
    BOOL Switch3IsPressed(void);
    WORD_VAL ReadPOT(void);

    I don't have modified the usb_config and the usb_descriptor because i don't know wich modified parameters.

    There are no problem for program the PIC with the ICD3, but USBdeviceSTATE is always =0x04 when the the program is stopped and =0x00 (detached state???) when the program run in debugger mode.

    The host not detect the board also after a reset.


    I can send to you my schematic and my code if you send me your email : bastien343085844@aol.com

    Sorry for my english, no very good...


    Thank you for your help
    Last edited by russion; 24th February 2012 at 15:47.



  5. #5
    Newbie level 3
    Points: 181, Level: 2

    Join Date
    Feb 2012
    Posts
    3
    Helped
    0 / 0
    Points
    181
    Level
    2

    Re: Problem to connect with USB self power to a PIC18F4550

    Hi all, you see here my schematics:

    Click image for larger version. 

Name:	proto2a.JPG 
Views:	17 
Size:	404.4 KB 
ID:	69635Click image for larger version. 

Name:	proto2b.JPG 
Views:	25 
Size:	319.7 KB 
ID:	69636


    I don't succes to configure TRISB, who know where the bits are configured ?
    Last edited by russion; 24th February 2012 at 16:02.



    •   AltAdvertisement

        
       

  6. #6
    Member level 5
    Points: 1,901, Level: 10
    Achievements:
    7 years registered

    Join Date
    Jan 2011
    Location
    Montpellier FRANCE
    Posts
    81
    Helped
    11 / 11
    Points
    1,901
    Level
    10

    Re: Problem to connect with USB self power to a PIC18F4550

    Hi,

    Thank you all.
    We succeed to resolve the problem.
    The PIC18F4550 had a bad behaviour(it had a destroyed USB or I/O port), but it was working with ICD3.
    It's a pitty because the student has lost many hours.

    Best regards
    Jose Miguel



  7. #7
    Administrator
    Points: 69,512, Level: 64
    Achievements:
    Created Album pictures Created Blog entry 7 years registered
    bigdogguru's Avatar
    Join Date
    Mar 2010
    Location
    Southwest, USA
    Posts
    9,832
    Helped
    2358 / 2358
    Points
    69,512
    Level
    64
    Blog Entries
    4

    Re: Problem to connect with USB self power to a PIC18F4550

    Quote Originally Posted by joseMiguel View Post
    We succeed to resolve the problem.
    The PIC18F4550 had a bad behaviour(it had a destroyed USB or I/O port), but it was working with ICD3.
    It's a pitty because the student has lost many hours.
    Yes, it is a pity, defective hardware can be difficult to troubleshoot.

    I knew for from your previous posts, you are very familiar with the PIC18F4550, particularly the USB module. And from the russion's description the hardware appeared to be connected correctly.


    Sorry, we could not be of more help in this case.

    BigDog



--[[ ]]--