macrocell_office_iot/espsens/espsens.ino

175 lines
5.1 KiB
C++

/* ESP8266 environmental sensor project
*
* This firmware provides features to use the NodeMCU ESP12 unit as an environmental sensor.
* Currently supported is the DHT22 temperature and humidity sensor.
* The sensor is to be connected to pin D2 of the NodeMCU ESP12 breakout card pin.
*
* (C) 2019 Macrocell - Environmental sensing solutions
* proudly presented by Macrocell - FPGA Innovators
*/
#include <ESP8266WiFi.h>
#include <Wire.h>
#include <PubSubClient.h>
#include "DHT.h"
#include "configuration.h"
#define TOPIC_BASE "sensor/" SENSOR_ID "/"
#define TOPIC_TEMP TOPIC_BASE "temperature"
#define TOPIC_HMID TOPIC_BASE "humidity"
#define TOPIC_HEAT TOPIC_BASE "heat_index"
#define TOPIC_ABHU TOPIC_BASE "abs_humidity"
#define DIFF_TEMP 0.3 // sensor has only 0.5°C accuracy, triggering on less is ludicrous
#define DIFF_HMID 2.5 // humidity doesn't change that much anyways
#define DIFF_HEAT 0.2 // this one's actually quite active
#define DIFF_ABHU 0.1 // small changes mean quite something
float hmid = 0; // humidity
float hmid_r = 0; // humidity
float abhu = 0; // absolute humidity
float abhu_r = 0; // absolute humidity
float temp = 0; // temperature
float temp_r = 0; // temperature
float heat = 0; // heat index
float heat_r = 0; // heat index
#define DHTPIN 4 // Digital pin connected to the DHT sensor
#define DHTTYPE DHT22 // DHT 22 (AM2302), AM2321
DHT dht(DHTPIN, DHTTYPE);
WiFiClient espClient;
PubSubClient client(espClient);
void setup() {
Serial.begin(SERIAL_BAUDRATE);
pinMode(LED_BUILTIN, OUTPUT);
digitalWrite(LED_BUILTIN, LOW);
setup_wifi();
client.setServer(MQTT_SERVER, MQTT_PORT);
dht.begin();
}
void setup_wifi() {
delay(10);
// Connect to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(WIFI_SSID);
WiFi.begin(WIFI_SSID, WIFI_PW);
WiFi.mode(WIFI_STA);
// blink LED fast until WiFi is connected
while (WiFi.status() != WL_CONNECTED) {
delay(200);
digitalWrite(LED_BUILTIN, HIGH);
Serial.print(".");
delay(200);
digitalWrite(LED_BUILTIN, LOW);
}
// WiFi connected
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void reconnect() {
// Loop until reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect(MQTT_CLIENT, MQTT_USER, MQTT_PW)) {
Serial.println("connected");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
digitalWrite(LED_BUILTIN, HIGH);
// Wait 5 seconds before retrying
delay(4000);
digitalWrite(LED_BUILTIN, LOW);
delay(1000);
}
}
}
bool checkVariation(float newValue, float prevValue, float maxDiff) {
return !isnan(newValue) &&
(newValue < prevValue - maxDiff || newValue > prevValue + maxDiff);
}
bool checkPlausibility(float newValue, float prevValue, float maxDiff) {
return (newValue < prevValue + (maxDiff * 10) || newValue > prevValue - (maxDiff * 10));
}
long lastMsg = 0;
long lastSent = 0;
bool published = false;
bool forcePublish = false;
bool publish (String desc, char *topic, float val, float &lastVal, float diff, bool force){
bool retval = false;
Serial.println("Sample " + desc + ": " + String(val).c_str());
if (checkVariation(val, lastVal, diff) or force) {
lastVal = val;
Serial.println("Sufficient variation on " + desc + ": " + String(val).c_str());
if (checkPlausibility(val, lastVal, diff) or force) {
Serial.println("Value published");
client.publish(topic, String(val).c_str(), true);
retval = true;
} else {
Serial.print("** ERROR: Value out of bounds, not published. Last value :");
Serial.println(String(lastVal).c_str());
}
}
return retval;
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
digitalWrite(LED_BUILTIN, HIGH);
long now = millis();
if (now - lastMsg > OPERATION_PERIOD / 2) {
if (OPERATION_BLINK_EN) {digitalWrite(LED_BUILTIN, LOW);}
}
if (now - lastMsg > OPERATION_PERIOD) {
lastMsg = now;
if (OPERATION_BLINK_EN) {digitalWrite(LED_BUILTIN, HIGH);}
hmid = dht.readHumidity();
temp = dht.readTemperature();
if (!isnan(hmid) && !isnan(temp)){
abhu = (6.112 * ( pow(2.71828, ((17.67 * temp) / (temp + 243.5))) * hmid * 2.1674)) / (273.15 + temp);
heat = dht.computeHeatIndex(temp, hmid, false);
}
published = false;
if (lastSent > FORCE_PERIOD) {
Serial.println(F("Forcing a publish of all values"));
forcePublish = true;
lastSent = 0;
}
published += publish("temperature", TOPIC_TEMP, temp, temp_r, DIFF_TEMP, forcePublish);
published += publish("humidity", TOPIC_HMID, hmid, hmid_r, DIFF_HMID, forcePublish);
published += publish("heat index", TOPIC_HEAT, heat, heat_r, DIFF_HEAT, forcePublish);
published += publish("absolute humidity", TOPIC_ABHU, abhu, abhu_r, DIFF_ABHU, forcePublish);
if (published == false) {
lastSent = lastSent + 1;
} else {
lastSent = 0;
}
forcePublish = false;
}
}