wiringPi_Blueberry/examples/Gertboard/7segments.c

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2023-08-11 15:53:17 +08:00
/*
* 7segments.c:
* Simple test program to see if we can drive a 7-segment LED
* display using the GPIO and little else on the Raspberry Pi
*
* Copyright (c) 2013 Gordon Henderson
***********************************************************************
*/
#undef PHOTO_HACK
#include <wiringPi.h>
#include <stdio.h>
#include <time.h>
#include <ctype.h>
#include <string.h>
/*
* Segment mapping
*
* --a--
* | |
* f b
* | |
* --g--
* | |
* e c
* | |
* --d-- p
*/
// GPIO Pin Mapping
static int digits [6] = { 7, 11, 10, 13, 12, 14 } ;
static int segments [7] = { 6, 5, 4, 3, 2, 1, 0 } ;
static const int segmentDigits [] =
{
// a b c d e f g Segments
// 6 5 4 3 2 1 0, // wiringPi pin No.
1, 1, 1, 1, 1, 1, 0, // 0
0, 1, 1, 0, 0, 0, 0, // 1
1, 1, 0, 1, 1, 0, 1, // 2
1, 1, 1, 1, 0, 0, 1, // 3
0, 1, 1, 0, 0, 1, 1, // 4
1, 0, 1, 1, 0, 1, 1, // 5
1, 0, 1, 1, 1, 1, 1, // 6
1, 1, 1, 0, 0, 0, 0, // 7
1, 1, 1, 1, 1, 1, 1, // 8
1, 1, 1, 1, 0, 1, 1, // 9
1, 1, 1, 0, 1, 1, 1, // A
0, 0, 1, 1, 1, 1, 1, // b
1, 0, 0, 1, 1, 1, 0, // C
0, 1, 1, 1, 1, 0, 1, // d
1, 0, 0, 1, 1, 1, 1, // E
1, 0, 0, 0, 1, 1, 1, // F
0, 0, 0, 0, 0, 0, 0, // blank
} ;
// display:
// A global variable which is written to by the main program and
// read from by the thread that updates the display. Only the first
// 6 characters are used.
char display [8] ;
/*
* displayDigits:
* This is our thread that's run concurrently with the main program.
* Essentially sit in a loop, parsing and displaying the data held in
* the "display" global.
*********************************************************************************
*/
PI_THREAD (displayDigits)
{
int digit, segment ;
int index, d, segVal ;
piHiPri (50) ;
for (;;)
{
for (digit = 0 ; digit < 6 ; ++digit)
{
for (segment = 0 ; segment < 7 ; ++segment)
{
d = toupper (display [digit]) ;
/**/ if ((d >= '0') && (d <= '9')) // Digit
index = d - '0' ;
else if ((d >= 'A') && (d <= 'F')) // Hex
index = d - 'A' + 10 ;
else
index = 16 ; // Blank
segVal = segmentDigits [index * 7 + segment] ;
digitalWrite (segments [segment], segVal) ;
}
digitalWrite (digits [digit], 1) ;
delay (2) ;
digitalWrite (digits [digit], 0) ;
}
}
}
/*
* setup:
* Initialise the hardware and start the thread
*********************************************************************************
*/
void setup (void)
{
int i, c ;
wiringPiSetup () ;
// 7 segments
for (i = 0 ; i < 7 ; ++i)
{ digitalWrite (segments [i], 0) ; pinMode (segments [i], OUTPUT) ; }
// 6 digits
for (i = 0 ; i < 6 ; ++i)
{ digitalWrite (digits [i], 0) ; pinMode (digits [i], OUTPUT) ; }
strcpy (display, " ") ;
piThreadCreate (displayDigits) ;
delay (10) ; // Just to make sure it's started
// Quick countdown LED test sort of thing
c = 999999 ;
for (i = 0 ; i < 10 ; ++i)
{
sprintf (display, "%06d", c) ;
delay (400) ;
c -= 111111 ;
}
strcpy (display, " ") ;
delay (400) ;
#ifdef PHOTO_HACK
sprintf (display, "%s", "123456") ;
for (;;)
delay (1000) ;
#endif
}
/*
* teenager:
* No explanation needed. (Nor one given!)
*********************************************************************************
*/
void teenager (void)
{
char *message = " feedbeef babe cafe b00b " ;
int i ;
for (i = 0 ; i < strlen (message) - 4 ; ++i)
{
strncpy (display, &message [i], 6) ;
delay (200) ;
}
delay (1000) ;
for (i = 0 ; i < 3 ; ++i)
{
strcpy (display, " ") ;
delay (150) ;
strcpy (display, " b00b ") ;
delay (250) ;
}
delay (1000) ;
strcpy (display, " ") ;
delay (1000) ;
}
/*
*********************************************************************************
* main:
* Let the fun begin
*********************************************************************************
*/
int main (void)
{
struct tm *t ;
time_t tim ;
setup () ;
teenager () ;
tim = time (NULL) ;
for (;;)
{
while (time (NULL) == tim)
delay (5) ;
tim = time (NULL) ;
t = localtime (&tim) ;
sprintf (display, "%02d%02d%02d", t->tm_hour, t->tm_min, t->tm_sec) ;
delay (500) ;
}
return 0 ;
}