'This code does a row-column scan for 2, 5x5 LED grids using two Maxim 7219.



DEFINE osc 4

output PORTB.0
output PORTC.3
output PORTC.4

'define DataPin, ClockPin, Load Pin
DPIN var PORTC.4
CPIN var PORTC.3
IOPIN var PORTB.0

'pauseDuration var byte

'temp1 var byte

'variables to put the current row, current column
tempRow var byte
tempCol var byte

'variables for all on/ all of on a certain row
ALL_ON var byte
ALL_OFF var byte

i var byte

' array to hold the columns, rows, threshold values, serial input
arrayColP VAR BYTE      ' All OFF
arrayColA VAR BYTE
arrayColB VAR BYTE
arrayColC VAR BYTE
arrayColD VAR BYTE
arrayRow var byte[8]

'============ Initialization of program happens here ============'
        ALL_ON = $FF
        ALL_OFF = $00
        
       ' pauseDuration = 10
        
        arrayColP = %10000000      ' All OFF
        arrayColA = %01000000
        arrayColB = %00100000
        arrayColC = %00010000
        arrayColD = %00001000
        
        
        arrayRow [0] = %00000001
        arrayRow [1] = %00000010
        arrayRow [2] = %00000011
        arrayRow [3] = %00000100
        arrayRow [4] = %00000101
        

    'XXXXAAAA 00000000
        
        high IOPIN              'set chip select line high
        PAUSE 10
        
        'first worry about decode mode. on power up device does not decode
        'so we do not need to do anything
        
        ' set the scan limit to xxxx1011xxxxxxxx (display Digit0,1,2,3,4,5,6,7 xxxxx111)
        low IOPIN
        SHIFTOUT DPIN, CPIN, 1, [%0000101100000100\16]
        high IOPIN
        PAUSE 10
        
        'set the intensity register, initially lights are at full intensity.
        low IOPIN
        SHIFTOUT DPIN, CPIN, 1, [%0000101000001111\16]
        high IOPIN
        PAUSE 10
        
        'disable shutdown mode xxxx1100xxxxxxx1 (shutdown mode xxxx1100xxxxxxx0)
        low IOPIN
        SHIFTOUT DPIN, CPIN, 1, [%0000110000000001\16]
        high IOPIN
        PAUSE 10
        
        'disable display mode xxxx1111xxxxxxx0 (display mode xxxx1100xxxxxxx1)
        low IOPIN
        SHIFTOUT DPIN, CPIN, 1, [%0000111100000000\16]
        high IOPIN
        PAUSE 10
        
        
        'turn them all off, so that we start off clean
        For i = 0 To 4
        low IOPIN
                SHIFTOUT DPIN, CPIN, 1, [arrayRow[i], ALL_OFF]
                SHIFTOUT DPIN, CPIN, 1, [arrayRow[i], ALL_OFF]
                high IOPIN
            Next i
            
            PAUSE 500
         
main:
            'scan the rows 0,1,2,3,4,5 by putting them on
             
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], ALL_ON]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], ALL_ON]
      high IOPIN
      PAUSE 500
          Next i
          
           'put the rows one by one
          
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[i], ALL_OFF]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], ALL_Off]
      high IOPIN
      Next i
      PAUSE 500
          
          ' put the decimal point segment ON on all the digits for the coloumn scan
   
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColP]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColP]
      high IOPIN
      Next i
          PAUSE 500
          
          ' put the 'A' segment ON on all the digits for the coloumn scan
          
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColA]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColA]
      high IOPIN
          Next i
          PAUSE 500
          
          ' put the 'B' segment ON on all the digits for the coloumn scan
          
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColB]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColB]
      high IOPIN
          Next i
          PAUSE 500
          
          ' put the 'C' segment ON on all the digits for the coloumn scan
          
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColC]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColC]
      high IOPIN
          Next i
          PAUSE 500
          
          ' put the 'D' segment ON on all the digits for the coloumn scan
          
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColD]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[I], arrayColD]
      high IOPIN
          Next i
      PAUSE 500
      
      'turn all the LED's off
          
          For i = 0 To 4
      low IOPIN
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[i], ALL_OFF]
      SHIFTOUT DPIN, CPIN, 1, [arrayRow[i], ALL_OFF]
      high IOPIN
      Next i
          
          
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