Hi,
I used the SRF02 some time ago. I attach the code I used at that time, dont
know if it is working (I dont work on the project anymore) and its
not "clean", but maybe it can serve as a starting point! You will need to
open the i2c before calling us_ranging() and close it if you dont need it
anymore.
Have fun!
-Cornelius
Am Dienstag, 14. Oktober 2008 schrieb Andrea Sassetti:
> I'm an absolute beginner in working with the fox-board.
> someone has interfaced with the fox-borad sensors srf04 or sfr08(i2c)?
> please kindly post a sourcecode. please!
>
> Andrea
--
Cornelius Claussen
opentek GbR
Mobile: +49 (0)175 6944518
E-Mail: [EMAIL PROTECTED]
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#include "globals.h"
int us_ranging()
{
int ret = 0;
#ifndef BUILD_FOR_HOST
// is it ready for ranging?
I2C_DATA i2cdata_us;
i2cdata_us.slave = 0xE0;
i2cdata_us.wbuf[ 0 ] = 0;
i2cdata_us.wlen = 1;
i2cdata_us.rlen = 1;
if ( EI2CNOERRORS != ioctl( fd_i2c, _IO( ETRAXI2C_IOCTYPE, I2C_WRITEREAD ), &i2cdata_us ) )
{
// ranging not ready, no new position
return (0);
}
if (i2cdata_us.rbuf[0] == 255) {return 0;}
// printf("%d, read ranging...\n",i2cdata_us.rbuf[0]);
// if it is idle, read ranging data
i2cdata_us.wbuf[ 0 ] = 2; // high byte
if ( EI2CNOERRORS != ioctl( fd_i2c, _IO( ETRAXI2C_IOCTYPE, I2C_WRITEREAD ), &i2cdata_us ) )
{
#ifdef DEBUG
printf("ERROR: I2C writeread error #%i\n");
#endif
// I2C_Close();
return (0);
}
unsigned char hi = i2cdata_us.rbuf[0];
i2cdata_us.wbuf[ 0 ] = 3; // lo byte
if ( EI2CNOERRORS != ioctl( fd_i2c, _IO( ETRAXI2C_IOCTYPE, I2C_WRITEREAD ), &i2cdata_us ) )
{
#ifdef DEBUG
printf("ERROR: I2C writeread error #%i\n");
#endif
// I2C_Close();
return (0);
}
unsigned char lo = i2cdata_us.rbuf[0];
// printf ("DEBUG: Ultrasonic: hi: %d, lo: %d",hi,lo);
unsigned short range = 0;
range = (unsigned short)(hi << 8) | lo;
// The distance is now in "range"
/*if (range >20 ) {
us_alt = range;
time (&us_timestamp);
ret = -1;
}*/
// emit next sonar burst
// printf("emit next burst...\n");
i2cdata_us.slave = 0xE0;
i2cdata_us.wbuf[ 0 ] = 0;
i2cdata_us.wbuf[ 1 ] = 0x51;
i2cdata_us.wlen = 2;
i2cdata_us.rlen = 1;
int err = ioctl( fd_i2c, _IO( ETRAXI2C_IOCTYPE, I2C_WRITE ), &i2cdata_us );
if ( EI2CNOERRORS != err )
{
printf("ERROR: I2C write error #%i\n", err);
return 0;
}
#endif
return ret;
#ifdef DEBUG
printf ("DEBUG: Ultrasonic: RANGING");
#endif
}
#include "globals.h"
int I2C_Open()
{
#ifndef BUILD_FOR_HOST
int RetVal = 0;
fd_i2c = open( "/dev/i2c", O_RDWR );
if ( fd_i2c <= 0 )
{
printf( "I2C: open error on /dev/i2c\n" );
RetVal = -1;
}
return( RetVal );
#else
return 0;
#endif
}
void I2C_Close()
{
#ifndef BUILD_FOR_HOST
close( fd_i2c );
#endif
}
