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| -rw-r--r-- | 7segment.c | 477 | ||||
| -rw-r--r-- | README | 7 |
2 files changed, 484 insertions, 0 deletions
diff --git a/7segment.c b/7segment.c new file mode 100644 index 0000000..4b2131b --- /dev/null +++ b/7segment.c @@ -0,0 +1,477 @@ +/* + * Raspberry Pi 4 digit 7 segment display effects without GPIO libraries + * Copyright Daniel Jones <daniel@danieljon.es> 2018 + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* + diagram + ======= + A + _ + F| |B + G - + E| |C + - + D + + GPIO memory mapping and associated snippets of code from Gert van Loo & Dom + https://elinux.org/RPi_GPIO_Code_Samples#Direct_register_access + */ + + +#include <stdio.h> +#include <stdlib.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <unistd.h> +#include <ctype.h> +#include <time.h> +#include <string.h> + +#define BCM2708_PERI_BASE 0x20000000 +#define GPIO_BASE (BCM2708_PERI_BASE + 0x200000) /* GPIO controller */ +#define PAGE_SIZE (4*1024) +#define BLOCK_SIZE (4*1024) + +int mem_fd; +void *gpio_map; + +// I/O access +volatile unsigned *gpio; + +// GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x) or SET_GPIO_ALT(x,y) +#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3)) +#define OUT_GPIO(g) *(gpio+((g)/10)) |= (1<<(((g)%10)*3)) +#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3)) + +#define GPIO_SET *(gpio+7) // sets bits which are 1 ignores bits which are 0 +#define GPIO_CLR *(gpio+10) // clears bits which are 1 ignores bits which are 0 + +#define GET_GPIO(g) (*(gpio+13)&(1<<g)) // 0 if LOW, (1<<g) if HIGH + +#define GPIO_PULL *(gpio+37) // Pull up/pull down +#define GPIO_PULLCLK0 *(gpio+38) // Pull up/pull down clock + +/* + * pins: + * real represents + * 17 -> digit 0 + * 18 -> digit 1 + * 27 -> digit 2 + * 22 -> digit 4 + * 23 -> segment A + * 24 -> segment B + * 25 -> segment C + * 4 -> segment D + * 2 -> segment E + * 3 -> segment F + * 8 -> segment G + * 7 -> segment DOT + */ + +enum segments +{ + /* refer to the diagram to know which value represents which segment */ + SEG_A = 1 << 0, + SEG_B = 1 << 1, + SEG_C = 1 << 2, + SEG_D = 1 << 3, + SEG_E = 1 << 4, + SEG_F = 1 << 5, + SEG_G = 1 << 6, + SEG_DOT = 1 << 7, +}; + +enum segmentpins +{ + PIN_SELECT1 = 17, + PIN_SELECT2 = 18, + PIN_SELECT3 = 27, + PIN_SELECT4 = 22, + PIN_A = 23, + PIN_B = 24, + PIN_C = 25, + PIN_D = 4, + PIN_E = 2, + PIN_F = 3, + PIN_G = 8, + PIN_DOT = 7, +}; + +enum characters +{ + CHAR_ZERO = SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F, + CHAR_ONE = SEG_B | SEG_C, + CHAR_TWO = SEG_A | SEG_B | SEG_D | SEG_E | SEG_G, + CHAR_THREE = SEG_A | SEG_B | SEG_C | SEG_D | SEG_G, + CHAR_FOUR = SEG_B | SEG_C | SEG_F | SEG_G, + CHAR_FIVE = SEG_A | SEG_C | SEG_D | SEG_F | SEG_G, + CHAR_SIX = SEG_A | SEG_C | SEG_D | SEG_E | SEG_F | SEG_G, + CHAR_SEVEN = SEG_A | SEG_B | SEG_C, + CHAR_EIGHT = SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F | SEG_G, + CHAR_NINE = SEG_A | SEG_B | SEG_C | SEG_D | SEG_F | SEG_G, + CHAR_A = SEG_A | SEG_B | SEG_C | SEG_E | SEG_F | SEG_G, + CHAR_B = SEG_C | SEG_D | SEG_E | SEG_F | SEG_G, + CHAR_C = SEG_A | SEG_D | SEG_E | SEG_F, + CHAR_D = SEG_B | SEG_C | SEG_D | SEG_E | SEG_G, + CHAR_E = SEG_A | SEG_D | SEG_E | SEG_F | SEG_G, + CHAR_F = SEG_A | SEG_E | SEG_F | SEG_G, + CHAR_G = SEG_A | SEG_B | SEG_C | SEG_D | SEG_F | SEG_G, + CHAR_H = SEG_B | SEG_C | SEG_E | SEG_F | SEG_G, + CHAR_I = SEG_B | SEG_C, + CHAR_J = SEG_B | SEG_C | SEG_D | SEG_E, + CHAR_L = SEG_D | SEG_E | SEG_F, + CHAR_N = SEG_C | SEG_E | SEG_G, + CHAR_O = SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F, + CHAR_P = SEG_A | SEG_B | SEG_E | SEG_F | SEG_G, + CHAR_R = SEG_E | SEG_G, + CHAR_S = SEG_A | SEG_C | SEG_D | SEG_F | SEG_G, + CHAR_T = SEG_D | SEG_E | SEG_F | SEG_G, + CHAR_U = SEG_C | SEG_D | SEG_E, + CHAR_Y = SEG_B | SEG_C | SEG_D | SEG_F | SEG_G, + CHAR_Z = SEG_A | SEG_B | SEG_D | SEG_E | SEG_G, + CHAR_DOT = SEG_DOT, +}; + +int digits[4] = +{ + PIN_SELECT1, + PIN_SELECT2, + PIN_SELECT3, + PIN_SELECT4, +}; + +char hexcharacters[16] = +{CHAR_ZERO, + CHAR_ONE, + CHAR_TWO, + CHAR_THREE, + CHAR_FOUR, + CHAR_FIVE, + CHAR_SIX, + CHAR_SEVEN, + CHAR_EIGHT, + CHAR_NINE, + CHAR_A, + CHAR_B, + CHAR_C, + CHAR_D, + CHAR_E, + CHAR_F +}; + +char ascii[127] = +{ + [46] = 0, + CHAR_DOT, + 0, + CHAR_ZERO, + CHAR_ONE, + CHAR_TWO, + CHAR_THREE, + CHAR_FOUR, + CHAR_FIVE, + CHAR_SIX, + CHAR_SEVEN, + CHAR_EIGHT, + CHAR_NINE, + [31] = 0, + 0, /* a space */ + [64] = 0, + CHAR_A, + CHAR_B, + CHAR_C, + CHAR_D, + CHAR_E, + CHAR_F, + CHAR_G, + CHAR_H, + CHAR_I, + CHAR_J, + 0, + CHAR_L, + 0, + CHAR_N, + CHAR_O, + CHAR_P, + 0, + CHAR_R, + CHAR_S, + CHAR_T, + CHAR_U, + 0, + 0, + 0, + CHAR_Y, + CHAR_Z, +}; + +void +setup_io(void) +{ + /* open /dev/gpiomem */ + if ((mem_fd = open("/dev/gpiomem", O_RDWR|O_SYNC) ) < 0) { + printf("can't open /dev/mem \n"); + exit(-1); + } + + /* mmap GPIO */ + gpio_map = mmap( + NULL, //Any adddress in our space will do + BLOCK_SIZE, //Map length + PROT_READ|PROT_WRITE,// Enable reading & writting to mapped memory + MAP_SHARED, //Shared with other processes + mem_fd, //File to map + GPIO_BASE //Offset to GPIO peripheral + ); + + close(mem_fd); //No need to keep mem_fd open after mmap + + if (gpio_map == MAP_FAILED) { + printf("mmap error %d\n", (int)gpio_map);//errno also set! + exit(-1); + } + + // Always use volatile pointer! + gpio = (volatile unsigned *)gpio_map; +} + +void +displaycharacter(unsigned char segs) +{ + (segs & SEG_A) ? GPIO_SET = 1 << PIN_A : (GPIO_CLR = 1 << PIN_A); + (segs & SEG_B) ? GPIO_SET = 1 << PIN_B : (GPIO_CLR = 1 << PIN_B); + (segs & SEG_C) ? GPIO_SET = 1 << PIN_C : (GPIO_CLR = 1 << PIN_C); + (segs & SEG_D) ? GPIO_SET = 1 << PIN_D : (GPIO_CLR = 1 << PIN_D); + (segs & SEG_E) ? GPIO_SET = 1 << PIN_E : (GPIO_CLR = 1 << PIN_E); + (segs & SEG_F) ? GPIO_SET = 1 << PIN_F : (GPIO_CLR = 1 << PIN_F); + (segs & SEG_G) ? GPIO_SET = 1 << PIN_G : (GPIO_CLR = 1 << PIN_G); + (segs & SEG_DOT) ? GPIO_SET = 1 << PIN_DOT : (GPIO_CLR = 1 << PIN_DOT); +} + +void +clearpins(void) +{ + GPIO_SET = 1 << PIN_SELECT1; + GPIO_SET = 1 << PIN_SELECT2; + GPIO_SET = 1 << PIN_SELECT3; + GPIO_SET = 1 << PIN_SELECT4; + GPIO_CLR = 1 << PIN_A; + GPIO_CLR = 1 << PIN_B; + GPIO_CLR = 1 << PIN_C; + GPIO_CLR = 1 << PIN_D; + GPIO_CLR = 1 << PIN_E; + GPIO_CLR = 1 << PIN_F; + GPIO_CLR = 1 << PIN_G; + GPIO_CLR = 1 << PIN_DOT; +} + +void +pinsetup(void) +{ + INP_GPIO(PIN_SELECT1); + OUT_GPIO(PIN_SELECT1); + INP_GPIO(PIN_SELECT2); + OUT_GPIO(PIN_SELECT2); + INP_GPIO(PIN_SELECT3); + OUT_GPIO(PIN_SELECT3); + INP_GPIO(PIN_SELECT4); + OUT_GPIO(PIN_SELECT4); + + + INP_GPIO(PIN_A); + OUT_GPIO(PIN_A); + INP_GPIO(PIN_B); + OUT_GPIO(PIN_B); + INP_GPIO(PIN_C); + OUT_GPIO(PIN_C); + INP_GPIO(PIN_D); + OUT_GPIO(PIN_D); + INP_GPIO(PIN_E); + OUT_GPIO(PIN_E); + INP_GPIO(PIN_F); + OUT_GPIO(PIN_F); + INP_GPIO(PIN_G); + OUT_GPIO(PIN_G); + INP_GPIO(PIN_DOT); + OUT_GPIO(PIN_DOT); + clearpins(); +} + +void +displayword(unsigned char str[4]) +{ + for (int i = 0; i < 4; i++) + { + GPIO_SET = 1 << digits[0]; + GPIO_SET = 1 << digits[1]; + GPIO_SET = 1 << digits[2]; + GPIO_SET = 1 << digits[3]; + GPIO_CLR = 1 << digits[i]; + displaycharacter(ascii[toupper(str[i])]); + usleep(1000); + } +} + +void +blinkword(unsigned char str[4], int repeat) +{ + clock_t start, end; + start = clock(); + unsigned char original[5]; + unsigned char print[5]; + strcpy(original, str); + strcpy(print, str); + int state = 1; + int repeats = 0; + while (1) + { + if ((double)(end-start) >= 10000) + { + if (state) + strcpy(print, "kkkkk"); + + else + strcpy(print, original); + state = !state; + if (repeat >= 0) + { + if (repeats >= (repeat*2)+1) /* *2 -> 5 flashes of the word */ + return; + repeats++; + } + start = clock(); + } + for (int i = 0; i < 4; i++) + { + GPIO_SET = 1 << digits[0]; + GPIO_SET = 1 << digits[1]; + GPIO_SET = 1 << digits[2]; + GPIO_SET = 1 << digits[3]; + GPIO_CLR = 1 << digits[i]; + displaycharacter(ascii[toupper(print[i])]); + usleep(1000); + } + + end = clock(); + } +} +int +converthour(int hour) +{ + switch (hour) + { + case 0: return 12; + case 13: return 1; + case 14: return 2; + case 15: return 3; + case 16: return 4; + case 17: return 5; + case 18: return 6; + case 19: return 7; + case 20: return 8; + case 21: return 9; + case 22: return 10; + case 23: return 11; + default: return hour; + } +} + +void +runclock(void) +{ + clock_t start, end; + start = clock(); + unsigned char timenow[5] = "0000"; + while (1) + { + if ((double)(end-start) >= 50000) + { + time_t t = time(NULL); + struct tm *tm = localtime(&t); + if (converthour(tm->tm_hour) < 10) + snprintf(timenow, 5, "k%d%02d", converthour(tm->tm_hour), tm->tm_min); + else + snprintf(timenow, 5, "%02d%02d", converthour(tm->tm_hour), tm->tm_min); + start = clock(); + } + for (int i = 0; i < 4; i++) + { + GPIO_SET = 1 << digits[0]; + GPIO_SET = 1 << digits[1]; + GPIO_SET = 1 << digits[2]; + GPIO_SET = 1 << digits[3]; + GPIO_CLR = 1 << digits[i]; + displaycharacter(ascii[toupper(timenow[i])]); + usleep(1000); + } + end = clock(); + } + +} + +void +scrollword(unsigned char *string) +{ + size_t stringlen = strlen(string); + char buffer[5] = " "; + clock_t start, end; + start = clock(); + size_t wordsize = strlen(string); + size_t buffsize = strlen(buffer); + size_t circbuffsize = wordsize + buffsize; + size_t position = 0; // start at character zero of word + + while (1) + { + if ((double)(end-start) >= 3000) + { + // https://stackoverflow.com/questions/48331360/scroll-a-word-through-an-array-in-c-from-right-to-left + // shift the buffer + for (size_t i = 0; i < (buffsize - 1); i++) + buffer[i] = buffer[i + 1]; + // fill in the last character + buffer[buffsize - 1] = position < wordsize ? string[position] : 'k'; + // increment the position in the imaginary circular source text + position = (position + 1) % circbuffsize; + start = clock(); + } + for (int i = 0; i < 4; i++) + { + GPIO_SET = 1 << digits[0]; + GPIO_SET = 1 << digits[1]; + GPIO_SET = 1 << digits[2]; + GPIO_SET = 1 << digits[3]; + GPIO_CLR = 1 << digits[i]; + displaycharacter(ascii[toupper(buffer[i])]); + usleep(1000); + } + end = clock(); + } + +} + +int +main(int argc, char *argv[]) +{ + setup_io(); + pinsetup(); + //runclock(); + if (argv[1]) + scrollword(argv[1]); + clearpins(); + return 0; +} + @@ -0,0 +1,7 @@ +Raspberry Pi 4 digit 7 segment display effects without GPIO libraries. +Sloppy code with lots of repeating the same portions. + +displayword(unsigned char str[5]) // simply display a word, use in a loop +blinkword(unsigned char str[4], int repeat) // blink word once plus any integer > 0. <0 will blink forever +runclock(void) // display the time on the display, forever +scrollword(char *string) // scroll the string from right to left with a small buffer of extra characters |