GET
Contents |
Action
Reads a byte from the hardware or software UART.
Reads data from a file opened in BINARY mode.
Syntax
GET #channel, var
GET #channel, var , [pos] [, length]
Remarks
GET in combination with the software/hardware UART reads one byte from the UART.
GET in combination with the AVR-DOS file system is very flexible and versatile. It works on files opened in BINARY mode and you can reads all data types.
|
A channel number, which identifies an opened file. This can be a hard coded constant or a variable. |
|
Var |
The variable or variable array that will be assigned with the data from the file |
|
Pos |
This is an optional parameter that may be used to specify the position where the reading must start from. This must be a long variable. |
|
Length |
This is an optional parameter that may be used to specify how many bytes must be read from the file. |
By default you only need to provide the variable name. When the variable is a byte, 1 byte will be read. When the variable is a word or integer, 2 bytes will be read. When the variable is a long or single, 4 bytes will be read. When the variable is a string, the number of bytes that will be read is equal to the dimensioned size of the string. DIM S as string * 10 , would read 10 bytes.
Note that when you specify the length for a string, the maximum length is 254. The maximum length for a non-string array is 65535.
In BASCOM-8051, GET was implemented to read only from the UART. While BASCOM-AVR supports GET for the UART, its primary purpose is to read from files with AVR-DOS. For the UART, GET is limited to read 1 byte, just like WAITKEY.
Partial Example
GET #1 , var ,,2 ' read 2 bytes, start at current position
GET #1, var , PS ' start at position stored in long PS
GET #1, var , PS, 2 ' start at position stored in long PS and read 2 bytes
See also
INITFILESYSTEM , OPEN , CLOSE, FLUSH , PRINT, LINE INPUT, LOC, LOF , EOF , FREEFILE , FILEATTR , SEEK , BSAVE ,BLOAD , KILL , DISKFREE , DISKSIZE , PUT , FILEDATE , FILETIME , FILEDATETIME , DIR , FILELEN , WRITE , INPUT
ASM
|
current position |
goto new position first |
|
Byte: |
|
|
_FileGetRange_1
Input:
r24: File number
X: Pointer to variable
T-Flag cleared |
_FileGetRange_1
Input:
r24: File number
X: Pointer to variable
r16-19 (A): New position (1-based)
T-Flag Set |
|
Word/Integer: |
|
|
_FileGetRange_2
Input:
r24: File number
X: Pointer to variable
T-Flag cleared |
_FileGetRange_2
Input:
r24: File number
X: Pointer to variable
r16-19 (A): New position (1-based)
T-Flag Set |
|
Long/Single: |
|
|
_FileGetRange_4
Input:
r24: File number
X: Pointer to variable
T-Flag cleared |
_FileGetRange_4
Input:
r24: File number
X: Pointer to variable
r16-19 (A): New position (1-based)
T-Flag Set |
|
String (<= 255 Bytes) with fixed length |
|
|
_FileGetRange_Bytes
Input:
r24: File number
r20: Count of Bytes
X: Pointer to variable
T-Flag cleared |
_FileGetRange_Bytes
Input:
r24: File number
r20: Count of bytes
X: Pointer to variable
r16-19 (A): New position (1-based)
T-Flag Set |
|
Array (> 255 Bytes) with fixed length |
|
|
_FileGetRange
Input:
r24: File number
r20/21: Count of Bytes
X: Pointer to variable
T-Flag cleared |
_FileGetRange
Input:
r24: File number
r20/21: Count of bytes
X: Pointer to variable
r16-19 (A): New position (1-based)
T-Flag Set |
Output from all kind of usage:
r25: Error Code
C-Flag on Error
X: requested info
Partial Example
'for the binary file demo we need some variables of different types Dim B As Byte , W As Word , L As Long , Sn As Single , Ltemp As Long Dim Stxt As String * 10 B = 1 : W = 50000 : L = 12345678 : Sn = 123.45 : Stxt = "test" '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 Seek(#2) ; " = LOC+1" 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 'now open the file again and write only the single Open "test.bin" For Binary As #2 L = 1 'specify the file position B = Seek(#2 , L) ' reset is the same as using SEEK #2,L Get#2 , B ' get the byte Get#2 , W ' get the word Get#2 , L ' get the long Get#2 , Sn ' get the single Get#2 , Stxt ' get the string Close #2
| Languages | English • Deutsch |
|---|