| commit | author | age | ||
| d6b4a7 | 1 | /********************************************************************************* |
| G | 2 | * Copyright: (C) 2021 LingYun IoT System Studio |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Filename: led.c | |
| 6 | * Description: This file is used to control RGB 3-colors LED | |
| 7 | * | |
| 8 | * | |
| 9 | * Pin connection: | |
| 10 | * RGB Led Module Raspberry Pi Board | |
| 11 | * R <-----> #Pin33(BCM GPIO13) | |
| 12 | * G <-----> #Pin35(BCM GPIO19) | |
| 13 | * B <-----> #Pin37(BCM GPIO26) | |
| 14 | * GND <-----> GND | |
| 15 | * | |
| 16 | * System install: | |
| 17 | * sudo apt install -y libgpiod-dev gpiod | |
| 18 | * | |
| 19 | * | |
| 20 | ********************************************************************************/ | |
| 21 | ||
| 22 | #include <stdio.h> | |
| 23 | #include <stdlib.h> | |
| 24 | #include <unistd.h> | |
| 25 | #include <fcntl.h> | |
| 26 | #include <dirent.h> | |
| 27 | #include <string.h> | |
| 28 | #include <time.h> | |
| 29 | #include <errno.h> | |
| 30 | #include <signal.h> | |
| 31 | ||
| 32 | #include <gpiod.h> | |
| 33 | ||
| 34 | #define DELAY 500 | |
| 35 | ||
| 36 | #define ON 1 | |
| 37 | #define OFF 0 | |
| 38 | ||
| 39 | /* Three LEDs code */ | |
| 40 | enum | |
| 41 | { | |
| 42 | LED_R = 0, | |
| 43 | LED_G, | |
| 44 | LED_B, | |
| 45 | LEDCNT, | |
| 46 | }; | |
| 47 | ||
| 48 | /* Three LEDs hardware information */ | |
| 49 | typedef struct led_info_s | |
| 50 | { | |
| 51 | const char *name; /* RGB 3-color LED name */ | |
| 52 | int gpio; /* RGB 3-color LED BCM pin number */ | |
| 53 | int active;/* RGB 3-color LED active GPIO level: 0->low 1->high */ | |
| 54 | struct gpiod_line *line; /* libgpiod line */ | |
| 55 | } led_info_t; | |
| 56 | ||
| 57 | static led_info_t leds_info[LEDCNT] = | |
| 58 | { | |
| 59 | {"red", 13, 1, NULL }, | |
| 60 | {"green", 19, 1, NULL }, | |
| 61 | {"blue", 26, 1, NULL }, | |
| 62 | }; | |
| 63 | ||
| 64 | /* Three LEDs API context */ | |
| 65 | typedef struct led_ctx_s | |
| 66 | { | |
| 67 | struct gpiod_chip *chip; | |
| 68 | led_info_t *leds; | |
| 69 | int count; | |
| 70 | } led_ctx_t; | |
| 71 | ||
| 72 | int init_led(led_ctx_t *ctx); | |
| 73 | int term_led(led_ctx_t *ctx); | |
| 74 | int turn_led(led_ctx_t *ctx, int which, int cmd); | |
| 75 | static inline void msleep(unsigned long ms); | |
| 76 | ||
| 77 | ||
| 78 | int g_stop = 0; | |
| 79 | ||
| 80 | void sig_handler(int signum) | |
| 81 | { | |
| 82 | switch( signum ) | |
| 83 | { | |
| 84 | case SIGINT: | |
| 85 | case SIGTERM: | |
| 86 | g_stop = 1; | |
| 87 | ||
| 88 | default: | |
| 89 | break; | |
| 90 | } | |
| 91 | ||
| 92 | return ; | |
| 93 | } | |
| 94 | ||
| 95 | int main(int argc, char *argv[]) | |
| 96 | { | |
| 97 | int rv; | |
| 98 | led_ctx_t led_ctx = | |
| 99 | { | |
| 100 | .chip = NULL, | |
| 101 | .leds = leds_info, | |
| 102 | .count = LEDCNT, | |
| 103 | }; | |
| 104 | ||
| 105 | if( (rv=init_led(&led_ctx)) < 0 ) | |
| 106 | { | |
| 107 | printf("initial leds gpio failure, rv=%d\n", rv); | |
| 108 | return 1; | |
| 109 | } | |
| 110 | printf("initial RGB Led gpios okay\n", rv); | |
| 111 | ||
| 112 | signal(SIGINT, sig_handler); | |
| 113 | signal(SIGTERM, sig_handler); | |
| 114 | ||
| 115 | while( !g_stop ) | |
| 116 | { | |
| 117 | turn_led(&led_ctx, LED_R, ON); | |
| 118 | msleep(DELAY); | |
| 119 | turn_led(&led_ctx, LED_R, OFF); | |
| 120 | msleep(DELAY); | |
| 121 | ||
| 122 | turn_led(&led_ctx, LED_G, ON); | |
| 123 | msleep(DELAY); | |
| 124 | turn_led(&led_ctx, LED_G, OFF); | |
| 125 | msleep(DELAY); | |
| 126 | ||
| 127 | turn_led(&led_ctx, LED_B, ON); | |
| 128 | msleep(DELAY); | |
| 129 | turn_led(&led_ctx, LED_B, OFF); | |
| 130 | msleep(DELAY); | |
| 131 | } | |
| 132 | ||
| 133 | term_led(&led_ctx); | |
| 134 | return 0; | |
| 135 | } | |
| 136 | ||
| 137 | int term_led(led_ctx_t *ctx) | |
| 138 | { | |
| 139 | int i; | |
| 140 | led_info_t *led; | |
| 141 | ||
| 142 | printf("terminate RGB Led gpios\n"); | |
| 143 | ||
| 144 | if( !ctx ) | |
| 145 | { | |
| 146 | printf("Invalid input arguments\n"); | |
| 147 | return -1; | |
| 148 | } | |
| 149 | ||
| 150 | if( !ctx->chip ) | |
| 151 | return 0; | |
| 152 | ||
| 153 | for(i=0; i<ctx->count; i++) | |
| 154 | { | |
| 155 | led = &ctx->leds[i]; | |
| 156 | ||
| 157 | if( led->line ) | |
| 158 | gpiod_line_release(led->line); | |
| 159 | } | |
| 160 | ||
| 161 | gpiod_chip_close(ctx->chip); | |
| 162 | return 0; | |
| 163 | } | |
| 164 | ||
| 165 | ||
| 166 | int init_led(led_ctx_t *ctx) | |
| 167 | { | |
| 168 | int i, rv; | |
| 169 | led_info_t *led; | |
| 170 | ||
| 171 | if( !ctx ) | |
| 172 | { | |
| 173 | printf("Invalid input arguments\n"); | |
| 174 | return -1; | |
| 175 | } | |
| 176 | ||
| 177 | ctx->chip = gpiod_chip_open_by_name("gpiochip0"); | |
| 178 | if( !ctx->chip ) | |
| 179 | { | |
| 180 | printf("open gpiochip failure, maybe you need running as root\n"); | |
| 181 | return -2; | |
| 182 | } | |
| 183 | ||
| 184 | ||
| 185 | for(i=0; i<ctx->count; i++) | |
| 186 | { | |
| 187 | led = &ctx->leds[i]; | |
| 188 | ||
| 189 | led->line = gpiod_chip_get_line(ctx->chip, led->gpio); | |
| 190 | if( !led->line ) | |
| 191 | { | |
| 192 | printf("open gpioline for %s[%d] failed\n", led->name, led->gpio); | |
| 193 | rv = -3; | |
| 194 | goto failed; | |
| 195 | } | |
| 196 | ||
| 197 | rv = gpiod_line_request_output(led->line, led->name, !led->active); | |
| 198 | if( rv ) | |
| 199 | { | |
| 200 | printf("request gpio output for %5s[%d] failed\n", led->name, led->gpio); | |
| 201 | rv = -4; | |
| 202 | goto failed; | |
| 203 | } | |
| 204 | ||
| 205 | //printf("request %5s led[%d] for gpio output okay\n", led->name, led->gpio); | |
| 206 | } | |
| 207 | ||
| 208 | return 0; | |
| 209 | ||
| 210 | failed: | |
| 211 | term_led(ctx); | |
| 212 | return rv; | |
| 213 | } | |
| 214 | ||
| 215 | int turn_led(led_ctx_t *ctx, int which, int cmd) | |
| 216 | { | |
| 217 | int rv = 0; | |
| 218 | led_info_t *led; | |
| 219 | ||
| 220 | if( !ctx || which<0 || which>=ctx->count ) | |
| 221 | { | |
| 222 | printf("Invalid input arguments\n"); | |
| 223 | return -1; | |
| 224 | } | |
| 225 | ||
| 226 | led = &ctx->leds[which]; | |
| 227 | ||
| 228 | if( OFF == cmd ) | |
| 229 | { | |
| 230 | gpiod_line_set_value(led->line, !led->active); | |
| 231 | } | |
| 232 | else | |
| 233 | { | |
| 234 | gpiod_line_set_value(led->line, led->active); | |
| 235 | } | |
| 236 | ||
| 237 | return 0; | |
| 238 | } | |
| 239 | ||
| 240 | static inline void msleep(unsigned long ms) | |
| 241 | { | |
| 242 | struct timespec cSleep; | |
| 243 | unsigned long ulTmp; | |
| 244 | ||
| 245 | cSleep.tv_sec = ms / 1000; | |
| 246 | if (cSleep.tv_sec == 0) | |
| 247 | { | |
| 248 | ulTmp = ms * 10000; | |
| 249 | cSleep.tv_nsec = ulTmp * 100; | |
| 250 | } | |
| 251 | else | |
| 252 | { | |
| 253 | cSleep.tv_nsec = 0; | |
| 254 | } | |
| 255 | ||
| 256 | nanosleep(&cSleep, 0); | |
| 257 | ||
| 258 | return ; | |
| 259 | } | |
| 260 | ||
