static void doGbr (int argc, char *argv [])
{
int channel ;
if (argc != 3)
{
fprintf (stderr, "Usage: %s gbr <channel>\n", argv [0]) ;
exit (1) ;
}
channel = atoi (argv [2]) ;
if ((channel < 0) || (channel > 1))
{
fprintf (stderr, "%s: gbr: Channel number must be 0 or 1\n", argv [0]) ;
exit (1) ;
}
if (gertboardAnalogSetup (64) < 0)
{
fprintf (stderr, "Unable to initialise the Gertboard SPI interface: %s\n", strerror (errno)) ;
exit (1) ;
}
printf ("%d\n", analogRead (64 + channel)) ;
}
static void doGbw (int argc, char *argv [])
{
int channel, value ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s gbw <channel> <value>\n", argv [0]) ;
exit (1) ;
}
channel = atoi (argv [2]) ;
value = atoi (argv [3]) ;
if ((channel < 0) || (channel > 1))
{
fprintf (stderr, "%s: gbw: Channel number must be 0 or 1\n", argv [0]) ;
exit (1) ;
}
if ((value < 0) || (value > 255))
{
fprintf (stderr, "%s: gbw: Value must be from 0 to 255\n", argv [0]) ;
exit (1) ;
}
if (gertboardAnalogSetup (64) < 0)
{
fprintf (stderr, "Unable to initialise the Gertboard SPI interface: %s\n", strerror (errno)) ;
exit (1) ;
}
analogWrite (64 + channel, value) ;
}
int main ()
{
int x1, x2 ;
double v1, v2 ;
printf ("\n") ;
printf ("Gertboard demo: Simple Voltmeters\n") ;
printf ("=================================\n") ;
// Always initialise wiringPi. Use wiringPiSys() if you don't need
// (or want) to run as root
wiringPiSetupSys () ;
// Initialise the Gertboard analog hardware at pin 100
gertboardAnalogSetup (100) ;
printf ("\n") ;
printf ("| Channel 0 | Channel 1 |\n") ;
for (;;)
{
// Read the 2 channels:
x1 = analogRead (100) ;
x2 = analogRead (101) ;
// Convert to a voltage:
v1 = (double)x1 / 1023.0 * 3.3 ;
v2 = (double)x2 / 1023.0 * 3.3 ;
// Print
printf ("| %6.3f | %6.3f |\r", v1, v2) ;
fflush (stdout) ;
}
return 0 ;
}
