dont show old mqtt values

src/main.cpp

@@ -67,6 +67,7 @@ struct __attribute__((packed)) sensor_readings_t {
   float uvb = NAN;
   float temperature_max = NAN; // °C
   float temperature_min = NAN; // °C
+  uint32_t lastUpdate = 0;
 } sensor_readings;
 
 sensor_readings_t sensors_a4cf1211c3e4, sensors_246f28d1fa5c, sensors_246f28d1a080, sensors_30aea47b0568;
@@ -176,6 +177,8 @@ void getSensorMeasurements() {
       sensor_readings.pm25 = pm.pm25;
     }
   }
+
+  sensor_readings.lastUpdate = millis();
 }
 
 
@@ -214,6 +217,7 @@ void receiveMqtt(const char* topic, const char* data) {
       } else if (strcmp("/voc", topic_last) == 0) {
         sensor->voc = atof(data);
       }
+      sensor->lastUpdate = millis();
     }
 }
 
@@ -373,10 +377,18 @@ void displayValues() {
     // other nodes
     display.setFont(NULL);
     display.setCursor(0, y_offset+70);
-    if (!ota.getMAC().equals("246f28d1fa5c")) display.printf("246f28d1fa5c: %4.1f %4.1f %6.1f\n", sensors_246f28d1fa5c.temperature, sensors_246f28d1fa5c.humidity, sensors_246f28d1fa5c.pressure);
-    if (!ota.getMAC().equals("a4cf1211c3e4")) display.printf("a4cf1211c3e4: %4.1f %4.1f %6.1f\n", sensors_a4cf1211c3e4.temperature, sensors_a4cf1211c3e4.humidity, sensors_a4cf1211c3e4.pressure);
-    if (!ota.getMAC().equals("246f28d1a080")) display.printf("246f28d1a080: %4.1f %4.1f %6.1f\n", sensors_246f28d1a080.temperature, sensors_246f28d1a080.humidity, sensors_246f28d1a080.pressure);
-    if (!ota.getMAC().equals("30aea47b0568")) display.printf("30aea47b0568: %4.1f %4.1f %6.1f\n", sensors_30aea47b0568.temperature, sensors_30aea47b0568.humidity, sensors_30aea47b0568.pressure);
+    if (!ota.getMAC().equals("246f28d1fa5c") && millis() - sensors_246f28d1fa5c.lastUpdate < 15*60*1000) {
+      display.printf("246f28d1fa5c: %4.1f %4.1f %6.1f\n", sensors_246f28d1fa5c.temperature, sensors_246f28d1fa5c.humidity, sensors_246f28d1fa5c.pressure);
+    }
+    if (!ota.getMAC().equals("a4cf1211c3e4") && millis() - sensors_a4cf1211c3e4.lastUpdate < 15*60*1000) {
+      display.printf("a4cf1211c3e4: %4.1f %4.1f %6.1f\n", sensors_a4cf1211c3e4.temperature, sensors_a4cf1211c3e4.humidity, sensors_a4cf1211c3e4.pressure);
+    }
+    if (!ota.getMAC().equals("246f28d1a080") && millis() - sensors_246f28d1a080.lastUpdate < 15*60*1000) {
+      display.printf("246f28d1a080: %4.1f %4.1f %6.1f\n", sensors_246f28d1a080.temperature, sensors_246f28d1a080.humidity, sensors_246f28d1a080.pressure);
+    }
+    if (!ota.getMAC().equals("30aea47b0568") && millis() - sensors_30aea47b0568.lastUpdate < 15*60*1000) {
+      display.printf("30aea47b0568: %4.1f %4.1f %6.1f\n", sensors_30aea47b0568.temperature, sensors_30aea47b0568.humidity, sensors_30aea47b0568.pressure);
+    }
 
   }
   while (display.nextPage());