*4.3.1.1 Petrol station hardware—user interface*

Initially, when the power board is supplied, the LCD screen shows the functions that the board performs when pressing the letter buttons on the keypad as shown in **Figure 28**.

• When we want to check the balance in RFID tag, we press A letter in keypad as shown in **Figure 29**. After pressing A letter, the LCD screen will display a message telling the customer to insert his card for the purpose of checking as shown in **Figure 30**. After checking the card, a message will appear on the screen showing the user's balance in Iraqi dinar as shown in **Figure 31**.

**Figure 27.** *The overall hardware system.*

**Figure 29.** *Press A to check.*

• For the purpose of updating or recharging the balance in the card, we press the letter B as shown in **Figure 32**. After pressing B letter, the LCD screen will display a message telling the customer to insert his card for the purpose of updating as shown in **Figure 33**. After identifying the ID of the card, a message appears on the screen asking the user, the amount to be recharged in the card as shown in

**Figure 31.** *User ID and your balance in card.*

**Figure 32.** *Press B to update.*

**Figure 33.** *Insert card to update.*

**Figure 34.** *Insert the amount of balance.*

> **Figure 34**. After entering the required amount and pressing the letter D, the updated quantity will appear on the screen in addition to the total amount after adding the new amount as shown in **Figure 35**.

**Figure 35.** *New amount after update.*

> • In order to obtain fuel, we press the letter C as shown in **Figure 36**. This function is common to all types of regular users (who has a balance and is deducted from his card after filling the fuel) and government users (who does not have a balance on the card, but whose debts are recorded on the government's account). After press C, the LCD screen will display a message telling the customer to insert his card to identify yourself as shown in **Figure 37**. After identifying the ID of the card and thus determining the type of customer, a message appears on the screen telling the customer to enter the amount of fuel to be filled as shown in **Figure 38**. The filling process begins after entering an amount of fuel less than the available balance as shown in **Figure 39**, and the amount deducted from the card and the amount of fuel filled appear on the LCD screen as shown in **Figure 40**. Because the fuel meter has a small error rate, we enter the quantity minus the error percentage.

**Figure 36.** *Press C to get fuel.*

**Figure 37.** *Insert card to identify.*

**Figure 38.** *Insert quantity of fuel we want to get.*

**Figure 39.** *Insert quantity of fuel we want to get.*

**Figure 40.** *Price and quantity of filled fuel.*

• When entering a quantity of fuel greater than the available balance in the card as shown in **Figure 41**, a message will appear telling the customer that the quantity entered is greater than the available balance as in the **Figure 42**.

**Figure 41.** *The quantity entered is greater than the available balance.*

**Figure 42.** *Entering more fuel than the available balance.*

**Figure 43.** *Check VIP user.*

**Figure 44.** *VIP user identify to get fuel.*

**Figure 45.** *Debts added and total debts.*

• When VIP government customer (want to get fuel, initially he swipes his card on the NFC RFID reader to identify as shown in **Figure 43**. Then enter a quantity of fuel VIP wants to get as shown in **Figure 44**. After fuel filling message display on LCD screen telling VIP user about quantity filled and depts as shown in **Figure 45**.
