#include "config.h" #ifdef HAVE_ESP8266 #include #include #endif #include #include #ifdef HAVE_SSD1306 #define HAVE_DISPLAY #include #include #include Adafruit_SSD1306 display(128, 64); #endif #if defined(HAVE_MH_Z19) && defined(SWAP_UART0) #define DPRINT(...) #define DPRINTLN(...) #else #define DPRINT(...) Serial.print(__VA_ARGS__) #define DPRINTLN(...) Serial.println(__VA_ARGS__) #endif #ifdef HAVE_MH_Z19 #define HAVE_CO2_SENSOR #define CO2_MIN 100 #define CO2_MAX 6000 int sensorCO2() { byte cmd[9] = {0xFF, 0x01, 0x86, 0x00, 0x00, 0x00, 0x00, 0x00, 0x79}; byte response[9]; Serial.write(cmd, 9); //request PPM CO2 Serial.readBytes(response, 9); if (response[0] != 0xFF) { DPRINTLN(F("Incorrect start byte from MH-Z19 sensor")); return -1; } if (response[1] != 0x86) { DPRINTLN(F("Incorrect response from MH-Z19 sensor")); return -1; } int responseHigh = (int) response[2]; int responseLow = (int) response[3]; int ppm = (256 * responseHigh) + responseLow; return ppm; } #endif #ifdef HAVE_DHT22 #include #define HAVE_TEMP_SENSOR #define HAVE_HUMID_SENSOR #define TEMP_MIN -40 #define TEMP_MAX 50 #define HUMID_MIN 0 #define HUMID_MAX 100 DHT dht(DHT22_PIN, DHT22); float sensorTemperature() { return dht.readTemperature(); } float sensorHumidity() { return dht.readHumidity(); } #endif #ifdef HAVE_SI7021 #include #define HAVE_TEMP_SENSOR #define HAVE_HUMID_SENSOR #define TEMP_MIN -40 #define TEMP_MAX 50 #define HUMID_MIN 0 #define HUMID_MAX 100 Adafruit_Si7021 si7021 = Adafruit_Si7021(); float sensorTemperature() { return si7021.readTemperature(); } float sensorHumidity() { return si7021.readHumidity(); } #endif #ifdef HAVE_BME280 #include #define HAVE_TEMP_SENSOR #define HAVE_HUMID_SENSOR #define TEMP_MIN -40 #define TEMP_MAX 50 #define HUMID_MIN 0 #define HUMID_MAX 100 Adafruit_BME280 bme; float sensorTemperature() { return bme.readTemperature(); } float sensorHumidity() { return bme.readHumidity(); } #endif String webString; ESP8266WebServer server(80); float humidity, temp_c, co2_ppm; bool health_status; unsigned long currentMillis, previousMillis; const long updateInterval = 5000; // update sensors every 5s #ifdef HAVE_SSD1306 unsigned long displayMillis; bool displayActive; const long displayTimeout = 15000; // show values on screen during 15s #endif void action_index() { server.send(200, "text/html", "Sensors server

Sensors server

You could get temperature, humidity or CO₂ values."); delay(100); } void action_temp() { #ifdef HAVE_TEMP_SENSOR update_sensors(); if (health_status) { webString = "Temperature: " + String(temp_c) + " C"; } else { webString = "Temperature: nan C"; } server.send(200, "text/plain", webString); #else server.send(404, "text/plain", "Temperature is not supported"); #endif } void action_humidity() { #ifdef HAVE_HUMID_SENSOR update_sensors(); if (health_status) { webString = "Humidity: " + String(humidity) + "%"; } else { webString = "Humidity: nan%"; } server.send(200, "text/plain", webString); #else server.send(404, "text/plain", "Humidity is not supported"); #endif } void action_co2() { #ifdef HAVE_CO2_SENSOR update_sensors(); if (health_status) { webString = "CO2: " + String(co2_ppm) + " ppm"; } else { webString = "CO2: nan ppm"; } server.send(200, "text/plain", webString); #else server.send(404, "text/plain", "CO2 is not supported"); #endif } void action_status_health() { if (health_status) { server.send(200, "text/plain", "OK"); } else { server.send(500, "text/plain", "FAIL"); } } void update_sensors() { #ifdef HAVE_HUMID_SENSOR float _humidity; #endif #ifdef HAVE_TEMP_SENSOR float _temp_c; #endif #ifdef HAVE_CO2_SENSOR int _co2_ppm; #endif currentMillis = millis(); if (previousMillis > currentMillis) { previousMillis = 0; DPRINTLN(F("millis() overflow")); } if (currentMillis - previousMillis >= updateInterval) { DPRINT(F("Refreshing sensors at ")); DPRINT(currentMillis); DPRINTLN(F(" msec")); previousMillis = currentMillis; health_status = false; #ifdef HAVE_TEMP_SENSOR _temp_c = sensorTemperature(); if (isnan(_temp_c) || _temp_c < TEMP_MIN || _temp_c > TEMP_MAX) { DPRINTLN(F("Failed to read temperature")); return; } temp_c = _temp_c; #endif #ifdef HAVE_HUMID_SENSOR _humidity = sensorHumidity(); if (isnan(_humidity) || _humidity < HUMID_MIN || _humidity > HUMID_MAX) { DPRINTLN(F("Failed to read humidity")); return; } humidity = _humidity; #endif #ifdef HAVE_CO2_SENSOR _co2_ppm = sensorCO2(); if (isnan(_co2_ppm) || _co2_ppm < CO2_MIN || _co2_ppm > CO2_MAX) { DPRINTLN(F("Failed to read CO2")); return; } co2_ppm = _co2_ppm; #endif health_status = true; update_display(); } else { DPRINTLN(F("Using cached sensor values")); } } void update_display() { #ifdef HAVE_SSD1306 char str_temp[6]; char str_humidity[6]; char str_co2[6]; currentMillis = millis(); if (displayMillis > currentMillis && !displayActive) { display.clearDisplay(); dtostrf(temp_c, 5, 1, str_temp); dtostrf(humidity, 5, 1, str_humidity); dtostrf(co2_ppm, 5, 0, str_co2); display.setCursor(0, 10); display.setFont(&FreeMono9pt7b); #ifdef HAVE_TEMP_SENSOR display.print("T "); display.print(str_temp); display.println("C"); #endif #ifdef HAVE_HUMID_SENSOR display.print("RH "); display.print(str_humidity); display.println("%"); #endif #ifdef HAVE_CO2_SENSOR display.print("CO2"); display.print(str_co2); display.println("ppm"); #endif display.ssd1306_command(SSD1306_DISPLAYON); display.display(); displayActive = true; } else { if (displayMillis <= currentMillis && displayActive) { display.ssd1306_command(SSD1306_DISPLAYOFF); displayActive = false; } } #endif } void setup() { #ifdef HAVE_SSD1306 display.begin(SSD1306_SWITCHCAPVCC, 0x3C); display.clearDisplay(); display.setTextColor(WHITE); display.setFont(); display.setCursor(0, 0); display.println("Starting..."); display.display(); #endif Serial.begin(9600); #ifdef SWAP_UART0 // See https://arduino-esp8266.readthedocs.io/en/latest/reference.html#serial for details // Switch UART0 from GPIO1 (TX) and GPIO3 (RX) to GPIO15 (TX) and GPIO13 (RX) Serial.swap(); #endif #if defined(HAVE_BME280) || defined(HAVE_SI7021) Wire.begin(I2C_SDA_PIN, I2C_SCL_PIN); Wire.setClock(100000); #endif #ifdef HAVE_DHT22 dht.begin(); #endif #ifdef HAVE_SI7021 si7021.begin(); #endif #ifdef HAVE_BME280 bme.begin(BME280_I2C_ADDRESS); #endif WiFi.mode(WIFI_STA); WiFi.begin(wifi_ssid, wifi_password); DPRINT("\n\r\n\rWorking to connect"); while (WiFi.status() != WL_CONNECTED) { delay(500); DPRINT("."); } DPRINTLN(""); DPRINTLN("Air sensors on esp8266"); DPRINT("Connected to "); DPRINTLN(wifi_ssid); #ifdef HAVE_SSD1306 display.clearDisplay(); display.setCursor(0, 0); display.print("WiFi: "); display.println(wifi_ssid); display.display(); #endif server.on("/", action_index); server.on("/temp", action_temp); server.on("/humidity", action_humidity); server.on("/co2", action_co2); server.on("/status/health", action_status_health); server.begin(); DPRINT("Server started at http://"); DPRINTLN(WiFi.localIP()); #ifdef HAVE_SSD1306 display.print("IP: "); display.println(WiFi.localIP()); display.display(); // initial delay for device stabilization display.println("Sensors preheat..."); display.display(); #endif delay(updateInterval); #ifdef HAVE_SSD1306 // OLED burnout protection pinMode(0, INPUT); displayMillis = millis() + displayTimeout; displayActive = false; #endif update_sensors(); } void loop() { server.handleClient(); #ifdef HAVE_SSD1306 if (digitalRead(0) == LOW) { displayMillis = millis() + displayTimeout; update_sensors(); } update_display(); #endif }