TM4C123G LaunchPad - 7 Segment LED Source Code

1. /*

2.  * Display minutes and seconds on the 4-digit 7-segment LED.

3.  *

4. */

6. #include <stdint.h>

7. #include <stdlib.h>

8. #include "inc/tm4c123gh6pm.h"

10. #define NO_OF_DIGITS    4

12. /* 0 - 9 pattern for the common cathode configuration */

13. unsigned char digitPattern[] = {0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F};

14. unsigned char digit_no[] = {0x10, 0x20, 0x40, 0x80};

16. /* for the common anode configuration */

17. // unsigned char digitPattern[] = {0xCF, 0xF9, 0xA4, 0xB0, 0x99, 0x92, 0x82, 0xF8, 0x80, 0x90};

18. // unsigned char digit_no[] = {0x1F, 0x2F, 0x4F, 0x8F};

20. void One_Second_Delay(void);

21. void delayMs(int n);

23. int seconds, minutes, minutesec;

25. int main(void)

26. {

27.     volatile unsigned long delay;

28.     int digits;

31.     seconds = 0;

32.     minutes = 0;

33.     minutesec = 0;

35.     SYSCTL_RCGC2_R |= 0x01;     /* enable clock to GPIOA */

36.     SYSCTL_RCGC2_R |= 0x02;     /* enable clock to GPIOB */

37.     delay = SYSCTL_RCGC2_R;     /* allow time for clock to start */

38.     delay = delay;

40.     GPIO_PORTB_DIR_R = 0xFF;    /* set all PORTB pins as output to drive segments */

41.     GPIO_PORTB_DEN_R = 0xFF;    /* set all PORTB pins as digital pins */

42.     GPIO_PORTB_DR8R_R = 0xFF;

44.     GPIO_PORTA_DIR_R = 0xF0;    /* set PORTA pin 7-4 as output to select digit */

45.     GPIO_PORTA_DEN_R = 0xF0;    /* set PORTA pin 7-4 as digital pins */

46.     GPIO_PORTA_DR8R_R = 0xF0;

48.     One_Second_Delay();

50.     for(;;) {

51.         for(digits = 0; digits < NO_OF_DIGITS; digits++ ) {

52.             GPIO_PORTA_DATA_R = digit_no[digits];           /* select digit */

54.             switch(digits) {

55.             case 0:

56.                 if( seconds >= 10)

57.                     minutesec = digitPattern[seconds%10];

58.                 else

59.                     minutesec = digitPattern[seconds];

60.                 break;

61.             case 1:

62.                 if( seconds >= 10)

63.                     minutesec = digitPattern[seconds/10];

64.                 else

65.                     minutesec = digitPattern[0];

66.                 break;

67.             case 2:

68.                 if( minutes >= 10)

69.                     minutesec = digitPattern[minutes%10];

70.                 else

71.                     minutesec = digitPattern[minutes];

72.                 break;

73.             case 3:

74.                 if( minutes >= 10)

75.                     minutesec = digitPattern[minutes/10];

76.                 else

77.                     minutesec = digitPattern[0];

78.                 break;

79.             default:

80.                 break;

81.             }

83.             /* drive pattern of that number on the segments */

84.             GPIO_PORTB_DATA_R = minutesec;

86.             delayMs(1);

88.             if( (NVIC_ST_CTRL_R & (1<<16) ) != 0) {

89.                 seconds += 1;

90.                 if(seconds >= 59 ) {

91.                     minutes++;

92.                     seconds = 0;

93.                 }

94.                 if(minutes >= 59 ) {

95.                     minutes = 0;

96.                     seconds = 0;

97.                 }

98.             }

99.         }

100.     }

101. }

103. void One_Second_Delay(void)

104. {

105.     NVIC_ST_RELOAD_R = 15999999;    /* Reload Value goes here */

106.     NVIC_ST_CTRL_R |= 0x5;          /* Triggering with external clock */

107. }

109. /* delay n milliseconds (16 MHz CPU clock) */

110. void delayMs(int n)

111. {

112.     int i, j;

114.     for(i = 0 ; i < n; i++)

115.         for(j = 0; j < 3180; j++)

116.             {} /* do nothing for 1 ms */

117. }