Byte arrays and math

jokerswild

G'day all,

This is for an SX28.

I have an byte array with·3 fields

ie;
gpsknots·· VAR·· Byte(2)
speed······ VAR·· Byte

where;
· gpsknots(0) = 1
· gpsknots(1) = 4
· gpsknots(2) = 3

To put this in a single variable i can use in operations i came up with this;

· speed = 0
· tmpB1 = gpsknots(0) * 100
· tmpB2 = gpsknots(1) * 10
· tmpB3 = tmpB1 + tmpB2
· speed = gpsknots(2)
· speed = speed + tmpB2
· speed = speed + tmpB1·
I'm still playing around with the code and haven't tested anything yet but can someone tell me if this will work and if its efficient?

Cheers!

Bean

speed = gpsknots(0) * 10
speed = speed + gpsknots(1)
speed = speed * 10
speed = speed + gpsknot(2)


Bean

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www.iElectronicDesigns.com

·

JonnyMac

Another approach is to create a function that takes the address of your array and the field width and converts it to a single value -- like this:

' Use: ARRAY2DEC address, digits

FUNC ARRAY2DEC
  tmpB1 = __PARAM1                              ' address of array
  tmpB2 = __PARAM2                              ' field width

  tmpW1 = 0                                     ' clear result
  DO WHILE tmpB2 > 0
    tmpW1 = tmpW1 * 10                          ' shift digits left
    tmpB3 = __RAM(tmpB1)                        ' get digit
    tmpW1 = tmpW1 + tmpB3                       ' add to result
    INC tmpB1                                   ' point to next element
    DEC tmpB2
  LOOP
  RETURN tmpW1
  ENDFUNC

Post Edited (JonnyMac) : 9/20/2008 12:56:44 AM GMT

jokerswild

Awesome thanks for the ideas guys!