array problem

svensson

Hello,

My array code does a strange thing. I cannot get elements 2.0 and 3.0 with this code:

PUB Main
··
· F.start
· DAC.Init(0, 1, 2)·············· 'CS, SCK, SDI respectively
· array[noparse][[/noparse]0] := 2.0
· array[noparse][[/noparse]1] := 3.0
·
· repeat index from 0 to 1
· x := F.FDiv(array[noparse][[/noparse]index],const)
· x := F.FRound(x)

{floating-point values in SPIN are 32bit and integer are 32 bits but floating-point values have a complete
different bitpattern as integer-values so you have to convert the float-value of w to an integer-value as
except the float-functions all other methods expect integer-values as parameters}

· DAC.Set(0,x)··················· 'Set Channel A to 2V ( 12 bit D/A conv )
· waitcnt(20_000_000 + cnt)




But with this, it works ( I get a value on my DAQ output ), just by changing array[noparse][[/noparse]index] through array[noparse][[/noparse]0]?????????????????

PUB Main
··
· F.start
· DAC.Init(0, 1, 2)·············· 'CS, SCK, SDI respectively
· array[noparse][[/noparse]0] := 2.0
· array[noparse][[/noparse]1] := 3.0
·
· repeat index from 0 to 1
· x := F.FDiv(array[noparse][[/noparse]0],const)
· x := F.FRound(x)

{floating-point values in SPIN are 32bit and integer are 32 bits but floating-point values have a complete
different bitpattern as integer-values so you have to convert the float-value of w to an integer-value as
except the float-functions all other methods expect integer-values as parameters}

· DAC.Set(0,x)··················· 'Set Channel A to 2V ( 12 bit D/A conv )
· waitcnt(20_000_000 + cnt)


Can someone say what's wrong in the code?

MagIO2

Did you maybe mean

DAC.Set( index, x )

??


You should use the button # if you poste code, because indentation gets lost otherwise. And indentation is an important information in SPIN.

StefanL38

Hello Svenson,

please use the archive-function of the propeller-tool to create a zip-file-archive that contains yopur COMPLETE code

You find this in main-menu of the propeller-tool. See attached picture.


I guess the bug is in the definition of the array. If you need an array of 10 elements you have to define

VAR
  byte MyArray[noparse][[/noparse]10] 

but the index-number run from 0 to 9

  MyArray[noparse][[/noparse]0] := 100 ' first element in the array has index ZERO
  MyArray := 100 'second elemet in the array has index ONE
  MyArray := 100 'third element in the array has index THREE
  MyArray := 100'etc
  MyArray := 100
  MyArray := 100
  MyArray[noparse][[/noparse]6] := 100
  MyArray[noparse][[/noparse]7] := 100
  MyArray[noparse][[/noparse]8] := 100
  MyArray[noparse][[/noparse]9] := 100 'tenth element in the array has index NINE

for small code-snippets use the SPIN code formatter

this creates code with a non-true-type standard-with-font so that indentions are easily too see

best regards

Stefan

svensson

Hello,

I think that isn't the problem. I don't know what's the problem. I make an array of 2 elements and I start with index 0. So I think that is ok!!!

MagIO2

As I said in my post ... indentation is very important in SPIN.

You need to indent both "x :="-lines plus the DAC.set and wait lines, so that they are inside of the loop! In your code the loop itself runs empty, executing no code. The rest is executed after the loop. Suppose the value of index will be 1, so you will only see the 3V.

Post Edited (MagIO2) : 10/30/2009 10:24:44 AM GMT

svensson

Thanks men!!!

Now it works fine. I'm am used programming in C, that's maybe the reason why I forget to indent.

Greetings,

Sven

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