temperature-alarm/iot/main.c

157 lines
3.3 KiB
C

#include <pthread.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#include <string.h>
#include <stdio.h>
#include <time.h>
#include <math.h>
#include <cjson/cJSON.h>
#include "brokers/amqp.h"
#include "devices/temperature.h"
#include "devices/display.h"
#include "devices/buzzer.h"
#include "device_properties.h"
void *sound_alarm(void *arg)
{
buzzer_handle_t buzzer = init_buzzer();
int delay = 170, length = 600;
for (int i = 0; i < 5; i++) {
sound_buzzer(buzzer, delay, length);
usleep(delay * 2 * length);
}
destroy_buzzer(buzzer);
return NULL;
}
void *watch_temperature(void *arg)
{
char *device_id = get_device_id();
printf("Device ID: %s\n", device_id);
display_handle_t display = init_display();
display_write_str(display, " ");
display_set_cursor_pos(display, 0, 1);
display_write_str(display, "Device.....");
display_write_str(display, device_id);
temperature_handle_t temp_handle = init_temperature();
get_temperature(temp_handle);
while (true) {
// Retrieve data
double min_temperature = get_min_temperature();
double max_temperature = get_max_temperature();
double temperature = get_temperature(temp_handle);
size_t timestamp = time(NULL);
// Send JSON
char *format = "{"
"\"temperature\": %lf,"
"\"device_id\": \"%s\","
"\"timestamp\": %zu"
"}";
char *str = malloc(snprintf(NULL, 0, format, temperature, device_id, timestamp) + 1);
sprintf(str, format, temperature, device_id, timestamp);
amqp_send_message("temperature-logs", str);
free(str);
// Print on display
str = malloc(17);
sprintf(str, "===[ %.1lf\xDF" "C ]===", temperature);
display_set_cursor_pos(display, 0, 0);
display_write_str(display, str);
free(str);
// Sound alarm if applicable
if (
min_temperature != NAN && max_temperature != NAN &&
(temperature < min_temperature || temperature > max_temperature)
) {
pthread_t alarm_thread;
pthread_create(&alarm_thread, NULL, sound_alarm, NULL);
}
printf("Temperature: %lf\n", temperature);
sleep(60);
}
free(device_id);
return NULL;
}
void broker_on_connect(void)
{
// Subscribe to messages from queue
char *queue = malloc(strlen("device-") + DEVICE_ID_SIZE + 1);
strcpy(queue, "device-");
strcat(queue, get_device_id());
amqp_subscribe("temperature-limits", queue);
free(queue);
// Start thread for watching temperature
pthread_t temperature_thread;
pthread_create(&temperature_thread, NULL, watch_temperature, NULL);
}
bool broker_on_message(char *exchange, char *message)
{
cJSON *json = cJSON_Parse(message);
if (cJSON_IsInvalid(json)) goto cancel;
// Get values
cJSON *reference_id = cJSON_GetObjectItem(json, "ReferenceId");
if (!cJSON_IsString(reference_id)) goto cancel;
cJSON *min_temp = cJSON_GetObjectItem(json, "TempLow");
if (!cJSON_IsNumber(min_temp)) goto cancel;
cJSON *max_temp = cJSON_GetObjectItem(json, "TempHigh");
if (!cJSON_IsNumber(min_temp)) goto cancel;
if (strcmp(reference_id->valuestring, get_device_id()) != 0) {
goto cancel;
}
printf("Min temperature: %lf, Max temperature: %lf\n", min_temp->valuedouble, max_temp->valuedouble);
set_min_temperature(min_temp->valuedouble);
set_max_temperature(max_temp->valuedouble);
cJSON_Delete(json);
return true;
cancel:
cJSON_Delete(json);
return false;
}
int main(void)
{
srand(time(NULL));
init_amqp();
return EXIT_SUCCESS;
}