Beginner having trouble with interrupt..


Results 1 to 11 of 11

Threaded View

  1. #10
    Join Date
    Oct 2008
    Posts
    65

    Default

    Hi everyone, I found a program which is the one I'm interested to learn, the code is from mister_e. As I understand I should use PortC.7 as RX. One line to RX and one line to GRND. Using the serial communicator. But it seems I can not trigger led on PortB1. anyone has an idea what I missed? Pls check my connection PC to PIC.
    this is the code from mister_e
    Code:
      '
        '   Simple program to handle USART interrupt using PIC16F877 @20MHZ
        '   ===============================================================
        '
        '   This program will Blink a LED on PORTB.0 to show
        '   that the PIC is running.  
        '
        '   This program also allow the user to activate or deactivate 
        '   a LED connected on PORTB.1 pin by sending command from a PC
        '   terminal software using 9600,n,8,1 setting
        '
        '   User command:
        '   =============
        '                1. If character "1" is received => enable the LED
        '                2. if character "2" is received => disable the LED
        '
        '
        'DEFINE LOADER_USED 1        ' using bootloader
        DEFINE OSC 20               ' running at 20 MHZ
        
        '    PORT setting
        '    ============
             '
             TRISC=%10000000        ' RC.7 => USART RX pin set to input
                                    ' all other pin set to output
                                    '
             TRISB=0                ' RB<7:0> set to output
        
        '    USART setting
        '    =============
             ' Since we will not use HSERIN/HSEROUT, we must
             ' write directly to internal PIC register
             ' 
             TXSTA=$24              ' enable transmit and SPBRGH=1
             RCSTA=$90              ' Enable USART and continuous receive
             SPBRG=129              ' BAUD RATE = 9600 BAUDS
       
        '    Interrupt definition
        '    ====================
             '
             PIE1.5   =1            ' enable USART receive interrupt
             INTCON.6 =1            ' enable peripheral interrupt
        
        '    Alias definition
        '    ================
             '
             RCIF      var PIR1.5   ' receiver interrupt
             StatusLED var PORTB.0  ' the LED who show a 'running process'
             UserLED   var PORTB.1  ' the LED that user want to control
             
        '    Variable definition
        '    ===================
             '
             Delay     var word     ' 
             DataIn    var byte     ' use to store RCREG content
             Discard   var byte     ' use to erase RCREG register
            
        '    Hardware/software initialisation
        '    ================================
             '
             PORTB=0                ' clear PORTB         
             on interrupt goto USARTInterrupt
            
    Start:
        '    Main program loop that make the user happy to
        '    see a LED flashing to mean that something is 
        '    running 
        '
        toggle statusled
        for delay = 1 to 5000       ' use a loop delay to ensure
          pauseus 5                 ' getting interrupt as fast as
          next                      ' possible
        goto start
        
    
    disable interrupt
    USARTInterrupt:
        '    Here's the interrupt routine who will make the user
        '    much happy by giving him the feeling to have the 
        '    control on the machine when the status of the user
        '    LED will change
        '
        RCSTA=0                     ' Disable serial port AND
                                    ' clear possible error (FERR,OERR)
                                    
        datain=RCREG                ' Get data
                                    
        while RCif                  ' wait untill the RCREG is empty
              discard=RCREG         ' by reading it and store result in a
        wend                        ' don't care variable
                                    
        select case datain          ' What to do with that data???
                                    
               case "1"             ' User selection = 1
                    userled=1       '      => Enable the LED
                                    
               case "2"             ' User selection =2
                    userled=0       '      => disable the LED
                                    
               end select           
        RCSTA=$90                   ' Re-enable the serial PORT AND
        resume                      ' get out of here
    enable interrupt

    thanks,
    mbox
    Attached Images Attached Images  

Similar Threads

  1. Can't ID interrupt source with this IntHandler??
    By jellis00 in forum mel PIC BASIC Pro
    Replies: 7
    Last Post: - 3rd June 2009, 02:35
  2. Very Trouble with 8722 Interrupt
    By smarino in forum mel PIC BASIC
    Replies: 4
    Last Post: - 5th March 2009, 09:48
  3. Help with Analog Interrupt
    By brid0030 in forum mel PIC BASIC Pro
    Replies: 7
    Last Post: - 13th February 2008, 18:14
  4. NEWBIE: Some basic questions using interrupts
    By JackPollack in forum mel PIC BASIC Pro
    Replies: 5
    Last Post: - 8th March 2006, 02:59
  5. USART interrupt not interrupting right
    By Morpheus in forum mel PIC BASIC Pro
    Replies: 12
    Last Post: - 6th March 2005, 01:07

Members who have read this thread : 0

You do not have permission to view the list of names.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts