The power source is 5V Adaptor. connected through the vin pin in the Arduino.

Why Adapter 5V?
the working voltage of  sensors is 3.3V-5.

I started by defining all the components: the buzzer, vibration motor, RGB LED, and four sensors. 

I created an integer to count how many times the tone will play. I also used a boolean and an integer to ensure the sound plays only once when a new card is inserted 

I used a void function to call and execute certain functions for playing tones. 

In the void setup(), I added the code to play a tone once the switch is turned on. Additionally, both green and red lights will be activated. Then, I defined each component as either an output or an input. 

I start the void loop() by creating an integer to store sensor readings. There are 12 readings in total (3 from each of the 4 sensors). I assign a name to each group of 3 sensors as follows:

• Letter1 = i1 + j1 + k1

• Letter2 = i2 + j2 + k2

• Letter3 = i3 + j3 + k3

• Word = i4 + j4 + k4

Here is how I assign sensors to Arabic letters and how words are formed from these letters. 

After the void loop(), I insert the function retrieval section. This includes a switch-case statement to check whether the answer is correct or incorrect and to play a specific melody based on the response. 

Before assembling all electronic components in the chassis, I tested the electronic circuit with all input and output components. Additionally, I created a sample flashcard, handwritten instead of printed, to test the pattern on the back and verify the size. 

After a lot of trail and errors The solution was to remove the small wooden parts between each sensor, as they were reflecting infrared signals to the receiver, even though the pattern was black. Additionally, to prevent any reflections, I painted the areas facing the sensors on the panel black.

If I had more time, I would add a screen to display the letters and words on the inserted flashcards, making the learning experience more interactive and engaging.