Video
Story
I want to briefly explain you story about how I have got this idea to build a token number display project. For past one year people have been undergoing vaccination everywhere in the world. I have observed that many people stand in a queue for 2-3 hrs sometimes to get vaccination. So I thought of building a low cost project using just two basic components. It is affordable and easy to use. I would really feel pleased if this project is useful for effective queue management. I hope it would definitely give comfort for the people and they need not feel uneasy waiting in a queue. They can get token number from administration staff and they will also roughly know the time it would take for their turn so they can sit on chairs or they can come back after some time. I really welcome people to recognize the importance of this project and implement it for effective queue management applications.
Hardware
We need to use ESP32 module and 4 Digit Seven Segment Display Board. We need to provide regulated 5V dc supply for the circuit operation. The board is having 7805 regulator IC which converts higher dc voltage from 12V 2A dc adapter to fixed 5V. For long distance communication range , we can also use external antenna for ESP32 module. Seven Segment Display Board is basically based on shift register IC. We just need three pins to connect any micro-controller with seven segment display board. Those are strobe, data and clock. We can write program and make pin connections accordingly.
Hardware Connection

Code:
Code is attached below.
Testing
download the free Bluetooth terminal App

and test it. You can see the result in video.