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RMU2 User Manual
7.2.1.1
Open()
Open a connection to the display device.
int open( const char* pathname, int flags);
Parameters
Type
Char
Name
Pathname
int
flags
Description
the path name to the DIO device file ( in this case
/dev/at89display )
one of the O_RDONLY, O_WRONLY or O_RDWR
options to open the file. Usually it would be O_RDWR ,
for reading and writing.
Return Value
Type
Int
Values
The file descriptor if successful
-1 if an error occurred.
Discussion
Open a data channel to the display controller.
7.2.1.2
Close()
Close an open connection to the display
int close ( int fd);
Parameters
Type
Char
Name
Description
fd
file descriptor to be closed
Return Value
Type
Int
Values
0 if successful
-1 if an error occurred.
Discussion
Close function for the display.
7.2.1.3
Write()
Writes the text string contained in the buffer to the display
ssize_t write ( int fd, const void* buf, size_t len);
Parameters
Type
Name
Fd
Char
Buf
Void*
Size_t Len
Description
file descriptor to be write to
pointer to buffer in memory that contains the text string to be display
number of bytes to be write
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