*4.3.2.2.1 Level of fuel*

Ultrasonic sensor is installed on the Arduino Mega microcontroller. The sensor sends fuel level information to microcontroller considering each


#### **Figure 49.** *Petrol station monitoring system Interface.*

**Figure 50.** *Petrol monitoring on ThingsBoard dashboard.*

microcontroller is a fuel station (MQTT client) and sends its information to the ThingsBoard server as shown in **Figure 51**.
