esp-air-monitor/main/main.c

/**
 * Author: Arthur Roberts (c) 2023
 *
 * License: GPLv3+
 */

#include "dht22.h"
#include "esp_log.h"
#include "esp_sntp.h"
#include "freertos/FreeRTOS.h"
#include "freertos/projdefs.h"
#include "freertos/task.h"
#include "nvs_flash.h"
#include "portmacro.h"
#include "sdkconfig.h"
#include "wifi.h"
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <inttypes.h>

static const char *TAG = "YASPAM";

static volatile bool run_dht = true;
static volatile bool run_pms5003 = true;

static TaskHandle_t dht22_handle = NULL;
static TaskHandle_t pms5003_handle = NULL;

typedef struct {
  uint8_t myt_sec;   // 0 -> 61
  uint8_t myt_min;   // 0 -> 69
  uint8_t myt_hour;  // 0 -> 23
  uint8_t myt_day;   // 1 -> 31
  uint8_t myt_month; // 0 -> 11 !!
  uint8_t myt_year;  // years since 1900
} my_time;

#ifdef CONFIG_PMS5003_ENABLED
#include "pms5003.h"

void read_from_pms5003() {
  while (run_pms5003) {
    // TODO: actually collect some data
    ESP_LOGI(TAG, "Got PMS5003 data!");
    // TODO: Write the data out somewhere
    vTaskDelay(pdMS_TO_TICKS(CONFIG_PMS5003_PERIOD_POLL * 1000));
  }
}
#endif /* CONFIG_PMS5003_ENABLED */

#ifdef CONFIG_DHT22_ENABLED
#include "dht22.h"

typedef struct {
  deci_percent rh;
  deci_degrees_c temp;
  my_time time;
} my_dht22_data;

my_dht22_data latest_datapoint;

void read_from_dht22() {
  // From datasheet:
  //  - Don't start within 1 second of powering on
  vTaskDelay(pdMS_TO_TICKS(1000));

  uint32_t num_samples_last_ten_mins = 0;
  float relative_humidity_tmp;
  float temperature_tmp;
  my_dht22_data ten_minute_average;

  while (run_dht) {
    int ret = dht22_read();
    if (ret != DHT22_OK) {
      dht22_handle_error(ret);
    } else {
      latest_datapoint.temp = dht22_temperature();
      latest_datapoint.rh = dht22_relative_humidity();

      // No point collecting rolling average if we don't know what the time is
      if (has_ntp_time_obtained_once()) {
        if (num_samples_last_ten_mins == 0) {
          relative_humidity_tmp = latest_datapoint.rh;
          temperature_tmp = latest_datapoint.temp;
        } else {
          relative_humidity_tmp +=
            ((float) latest_datapoint.rh - relative_humidity_tmp) /
              ((float) num_samples_last_ten_mins + 1.0);
          temperature_tmp +=
            ((float) latest_datapoint.temp - temperature_tmp ) /
              ((float) num_samples_last_ten_mins + 1.0);
        }
        num_samples_last_ten_mins += 1;
        ESP_LOGI(TAG, "latest_datapoint.temp: %"PRIi16, latest_datapoint.temp);
        ESP_LOGI(TAG, "ten_minute_average.temp: %f, num_samples: %"PRIu32, temperature_tmp, num_samples_last_ten_mins);

        // This should be: if (10 minutes of sample taken)
        // TODO: check max samples / second that can fit in 10 minutes
        if (num_samples_last_ten_mins >=
            ((10 * 60) / (CONFIG_DHT22_PERIOD_POLL))) {
          ESP_LOGW(TAG, "10 minutes of samples collected. Average temp: %f", temperature_tmp);
          num_samples_last_ten_mins = 0;

          time_t epoch;
          time(&epoch);
          struct tm *timeinfo = localtime(&epoch);

          // There must be a better way - I couldn't figure out how to do it
          // nicely all at once
          ten_minute_average.time.myt_sec = timeinfo->tm_sec;
          // -5 to get the middle of the averaged window
          ten_minute_average.time.myt_min = timeinfo->tm_min - 5;
          ten_minute_average.time.myt_hour = timeinfo->tm_hour;
          ten_minute_average.time.myt_day = timeinfo->tm_mday;
          ten_minute_average.time.myt_month = timeinfo->tm_mon;
          ten_minute_average.time.myt_year = timeinfo->tm_year;

          // TODO: Consider rounding this number - although, .1 of a degree C
          //  no one is going to miss that. Probably the calculation require to
          //  do the rounding would affect the temperature that much anyways haha
          ten_minute_average.temp = temperature_tmp;
          ten_minute_average.rh = relative_humidity_tmp;
          ESP_LOGW(TAG, "ten_min_avg.temp %" PRIi16 ", .rh %" PRIu16, ten_minute_average.temp, ten_minute_average.rh);

          // TODO: Write the data out somewhere - into RAM maybe
          // TODO: maybe push the data somewhere - or put a flag up that data
          // can be pushed
          //  ^ could do a cute Semaphore thingy here - I don't think I've
          //  actually used one before
        }
      }
    }
    vTaskDelay(pdMS_TO_TICKS(CONFIG_DHT22_PERIOD_POLL * 1000));
  }
}
#endif /* CONFIG DHT22_ENABLED */

void app_main(void) {
  esp_err_t ret = nvs_flash_init();
  if (ret == ESP_ERR_NVS_NO_FREE_PAGES ||
      ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
    ESP_ERROR_CHECK(nvs_flash_erase());
    ret = nvs_flash_init();
  }
  ESP_ERROR_CHECK(ret);

#ifdef CONFIG_DHT22_ENABLED
  xTaskCreate(read_from_dht22, "DHT22",
              4 * 1024, // honestly I have _no_ idea
              NULL,
              5, // no idea either
              &dht22_handle);

#endif /* CONFIG_DHT22_ENABLED */

#ifdef CONFIG_PMS5003_ENABLED

  xTaskCreate(read_from_pms5003, "PMS5003",
              4 * 1024, // honestly I have _no_ idea
              NULL,
              5, // no idea either
              &pms5003_handle);

#endif /* CONFIG_PMS5003_ENABLED */
  start_wifi();

}