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BASCOM AVR, help reference (2007).PDF

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	© MCS Electronics, 1995-2007
Remarks
bFileNumber	(Byte) Filenumber, which identifies an opened file
LFileLength	(Long) Variable, which assigned with the Length of the file (1-based)

This function returns the length of an opened file. If an error occurs, 0 is returned. Check DOS-Error in variable gbDOSError.

See also

INITFILESYSTEM , OPEN , CLOSE, FLUSH , PRINT, LINE INPUT, LOC, EOF , FREEFILE , FILEATTR , SEEK , BSAVE , BLOAD , KILL , DISKFREE , DISKSIZE , GET , PUT , FILEDATE , FILETIME , FILEDATETIME , DIR , FILELEN , WRITE , INPUT

ASM

Calls	_FileLOF
Input	r24: filenumber	X: Pointer to Long-variable, which gets th result
Output	r25: Errorcode	C-Flag: Set on Error

Example

'open the file in BINARY mode Open "test.biN" For Binary As #2 Put #2 , B ' write a byte

Put #2 , W ' write a word Put #2 , L ' write a long

Ltemp = Loc(#2)+ 1 ' get the position of the next byte Print Ltemp ;" LOC"' store the location of the file pointer Print Lof(#2);" length of file"

Print Fileattr(#2);" file mode"' should be 32 for binary Put #2 , Sn ' write a single

Put #2 , Stxt ' write a string

Flush #2 ' flush to disk

Close #2

LOCAL

Action

Dimensions a variable LOCAL to the function or sub program.

Syntax

LOCAL var As Type

Remarks

Var	The name of the variable
Type	The data type of the variable.

There can be only LOCAL variables of the type BYTE, INTEGER, WORD, LONG, SINGLE or STRING.

page -558-

A LOCAL variable is a temporary variable that is stored on the frame.

When the SUB or FUNCTION is terminated, the memory will be released back to the frame. BIT variables are not possible because they are GLOBAL to the system.

The AT , ERAM, SRAM, XRAM directives can not be used with a local DIM statement. Also local arrays are not possible.

See also

DIM

ASM

NONE

Example

'-----------------------------------------------------------------------------
------------	: declare.bas
'name	: declare.bas
'copyright	: (c) 1995-2005, MCS Electronics
'purpose	: demonstrate using declare
'micro	: Mega48
'suited for demo	: yes
'commercial addon needed	: no
' Note that the usage of SUBS works different in BASCOM-8051
'-----------------------------------------------------------------------------
------------
$regfile = "m48def.dat"	' specify the used
micro	' used crystal
$crystal = 4000000	' used crystal
frequency	' use baud rate
$baud = 19200	' use baud rate
$hwstack = 32	' default use 32
for the hardware stack	' default use 10
$swstack = 10	' default use 10
for the SW stack	' default use 40
$framesize = 40	' default use 40
for the frame space

' First the SUB programs must be declared

'Try a SUB without parameters

Declare Sub Test2

'SUB with variable that can not be changed(A) and

'a variable that can be changed(B1), by the sub program

'When BYVAL is specified, the value is passed to the subprogram

'When BYREF is specified or nothing is specified, the address is passed to 'the subprogram

Declare Sub Test(byval A As Byte , B1 As Byte) Declare Sub Testarray(byval A As Byte , B1 As Byte) 'All variable types that can be passed

'Notice that BIT variables can not be passed. 'BIT variables are GLOBAL to the application

Declare Sub Testvar(b As Byte , I As Integer , W As Word , L As Long , S As String)

page -559-

'passing string arrays needs a different syntax because the length of the strings must be passed by the compiler

'the empty () indicated that an array will be passed

Declare Sub Teststr(b As Byte , Dl() As String)

Dim Bb As Byte , I As Integer , W As Word , L As Long , S As String * 10

'dim used variables
Dim Ar(10) As Byte	'strng array
Dim Sar(10) As String * 8	'strng array
For Bb = 1 To 10	'fill the array
Sar(bb) = Str(bb)	'fill the array
Next

Bb = 1

'now call the sub and notice that we always must pass the first address with index 1

Call Teststr(bb , Sar(1))

Call Test2	'call sub
Test2	'or use without

CALL

'Note that when calling a sub without the statement CALL, the enclosing

parentheses must be left out
Bb = 1	'call sub with
Call Test(1 , Bb)	'call sub with
parameters	'print value that
Print Bb	'print value that
is changed
'now test all the variable types
Call Testvar(bb , I , W , L , S )
Print Bb ; I ; W ; L ; S
'now pass an array
'note that it must be passed by reference
Testarray 2 , Ar(1)
Print "ar(1) = " ; Ar(1)
Print "ar(3) = " ; Ar(3)
$notypecheck	' turn off type
checking
Testvar Bb , I , I , I , S
'you can turn off type checking when you want to pass a block of memory
$typecheck	'turn it back on
End

'End your code with the subprograms

'Note that the same variables and names must be used as the declared ones

Sub Test(byval A As Byte , B1 As Byte)	'start sub
Print A ; " " ; B1	'print passed
variables	'change value
B1 = 3	'change value
'You can change A, but since a copy is passed to the SUB,
'the change will not reflect to the calling variable
End Sub
Sub Test2	'sub without
parameters
Print "No parameters"
End Sub

page -560-

Sub Testvar(b As Byte , I As Integer , W As Word , L As Long , S As String) Local X As Byte

X	=	5	'assign local
B	=	X
I	=	-1
W	=	40000
L	=	20000
S = "test"
End Sub
Sub Testarray(byval A As Byte , B1 As Byte)			'start sub
Print A ; " " ; B1			'print passed
variables			'change value of
B1 = 3
element with index 1			'specify the index
B1(1) = 3
which does the same as the line above			'modify other
B1(3) = 3
element of array

'You can change A, but since a copy is passed to the SUB, 'the change will not reflect to the calling variable

End Sub

'notice the empty() to indicate that a string array is passed

Sub Teststr(b As Byte , Dl() As String) Dl(b) = Dl(b) + "add"

End Sub

LOCATE

Action

Moves the LCD cursor to the specified position.

Syntax

LOCATE y , x

Remarks

XConstant or variable with the position. (1-64*)

YConstant or variable with the line (1 - 4*)

*Depending on the used display

See also

CONFIG LCD , LCD , HOME , CLS

Partial Example

LCD "Hello"

Locate 1,10

LCD "*"

page -561-

LOG

Action

Returns the natural logarithm of a single variable.

Syntax

Target = LOG(source)

Remarks

Target	The single that is assigned with the LOG() of single target.
Source	The source single to get the LOG of.

See also

EXP , LOG10

Example

Show sample

LOG10

Action

Returns the base 10 logarithm of a single variable.

Syntax

Target = LOG10(source)

Remarks

Target	The single that is assigned with the base 10 logarithm of single target.
Source	The source single to get the base 10 LOG of.

See also

EXP , LOG

Example

Show sample

LOOKDOWN

page -562-

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