Make things async and allow for backlight toggle

vremenska-postaja.ino

@@ -6,33 +6,18 @@
 LiquidCrystal_I2C lcd(0x27, 16, 2);
 static TEWeatherShield weatherShield;
 
+int command = 0;
+int led = 1;
+bool mode = true;
+unsigned long previousMillis = 0;
+const long interval = 10000;
+
 void setup() {
   Serial.begin(9600);
   weatherShield.begin();
 
   lcd.init();
   lcd.backlight();
-  lcd.println("Vremenska postaja");
-  lcd.clear();
-}
-
-// Print temperature and humidity to LCD
-void printLCD(float temperature, float humidity, float pressure) {
-    lcd.clear();
-
-    String temp = "T: " + (String)temperature + " C";
-    lcd.setCursor(2, 0);
-    lcd.print(temp);
-
-    String hum = "H: " + (String)humidity + " %RH";
-    lcd.setCursor(2, 1);
-    lcd.print(hum);
-
-    delay(10000);
-
-    String pres = "P: " + (String)pressure + " hPa";
-    lcd.setCursor(2, 1);
-    lcd.print(pres);
 }
 
 // Measure from HTU21D
@@ -143,6 +128,27 @@ float measure_tsd305(String data) {
   }
 }
 
+// Print temperature and humidity to LCD
+void printLCD(float temperature, float humidity, float pressure) {
+    lcd.clear();
+
+    String temp = "T: " + (String)temperature + " C";
+    lcd.setCursor(2, 0);
+    lcd.print(temp);
+
+    if (mode == true) {
+      String hum = "H: " + (String)humidity + " %RH";
+      lcd.setCursor(2, 1);
+      lcd.print(hum);
+      mode = false;
+    } else {
+      String pres = "P: " + (String)pressure + " hPa";
+      lcd.setCursor(2, 1);
+      lcd.print(pres);
+      mode = true;
+    }
+}
+
 float avg(String data) {
   if (data == "temp") {
     float avgTemp = (measure_htu21d("temp") + measure_ms5637("temp") + measure_ms8607("temp") + measure_tsys01("temp") + measure_tsd305("temp")) / 5;
@@ -156,21 +162,47 @@ float avg(String data) {
   }
 }
 
+void toggleLed() {
+  if (led == 0) {
+    lcd.setBacklight(HIGH);
+    led = 1;
+  } else {
+    lcd.setBacklight(LOW);
+    led = 0;
+  }
+}
+
 void loop() {    
+  unsigned long currentMillis = millis();
+
+  if (currentMillis - previousMillis >= interval) {
+    previousMillis = currentMillis;
     StaticJsonDocument<100> jsonBuffer;
 
     float temperature = avg("temp");
     float pressure = avg("pres");
     float humidity = avg("humi");
 
+    // Don't print to LCD if backlight is off
+    if (led == 1) {
       printLCD(temperature, humidity, pressure);
+    }
 
+    // Get data and send it over serial
     jsonBuffer["temperature"] = temperature;
     jsonBuffer["humidity"] = humidity;
     jsonBuffer["pressure"] = pressure;
 
     serializeJson(jsonBuffer, Serial);
     Serial.println();
-
-  delay(2000);
+  }
+
+  Serial.flush();
+  command = Serial.read();
+  // 84 = T
+  if (command == 84) {
+    toggleLed();
+    //Serial.println("LED toggled");
+    //Make this return some JSON state of the LED to Home Assistant
+  }
 }