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: channel must be 0 or 1\n", argv [0]) ;
exit (1) ;
}
if (gertboardSPISetup () == -1)
{
fprintf (stderr, "Unable to initialise the Gertboard SPI interface: %s\n", strerror (errno)) ;
exit (1) ;
}
printf ("%d\n",gertboardAnalogRead (channel)) ;
}
static void doGbw (int argc, char *argv [])
{
int channel, value ;
if (argc != 4)
{
fprintf (stderr, "Usage: %s gbr <channel> <value>\n", argv [0]) ;
exit (1) ;
}
channel = atoi (argv [2]) ;
value = atoi (argv [3]) ;
if ((channel < 0) || (channel > 1))
{
fprintf (stderr, "%s: channel must be 0 or 1\n", argv [0]) ;
exit (1) ;
}
if ((value < 0) || (value > 1023))
{
fprintf (stderr, "%s: value must be from 0 to 255\n", argv [0]) ;
exit (1) ;
}
if (gertboardSPISetup () == -1)
{
fprintf (stderr, "Unable to initialise the Gertboard SPI interface: %s\n", strerror (errno)) ;
exit (1) ;
}
gertboardAnalogWrite (channel, value) ;
}
int main ()
{
int quietLevel, min, max ;
int i, sum ;
unsigned int tStart, tEnd ;
printf ("\n") ;
printf ("Gertboard demo: VU Meter\n") ;
printf ("========================\n") ;
wiringPiSetup () ;
gertboardSPISetup () ;
ledPercent (0) ;
for (i = 0 ; i < 8 ; ++i)
pinMode (i, OUTPUT) ;
for (bPtr = 0 ; bPtr < B_SIZE ; ++bPtr)
buffer [bPtr] = 99 ;
tPeriod = 1000000 / 1000 ;
printf ("Shhhh.... ") ; fflush (stdout) ;
delay (1000) ;
printf ("Sampling quiet... ") ; fflush (stdout) ;
tStart = micros () ;
tNextSampleTime = micros () ;
for (bPtr = 0 ; bPtr < B_SIZE ; ++bPtr)
sample () ;
tEnd = micros () ;
quietLevel = 0 ;
max = 0 ;
min = 1024 ;
for (i = 0 ; i < B_SIZE ; ++i)
{
quietLevel += buffer [i] ;
if (buffer [i] > max) max = buffer [i] ;
if (buffer [i] < min) min = buffer [i] ;
}
quietLevel /= B_SIZE ;
printf ("Done. Quiet level is: %d [%d:%d] [%d:%d]\n", quietLevel, min, max, quietLevel - min, max - quietLevel) ;
printf ("Time taken for %d reads: %duS\n", B_SIZE, tEnd - tStart) ;
for (bPtr = 0 ;;)
{
sample () ;
sum = 0 ;
for (i = 0 ; i < S_SIZE ; ++i)
sum += buffer [i] ;
sum /= S_SIZE ;
sum = abs (quietLevel - sum) ;
sum = (sum * 1000) / quietLevel ;
ledPercent (sum) ;
if (++bPtr > S_SIZE)
bPtr = 0 ;
}
return 0 ;
}
