Help with making Walkie Talkie

It is possible to make a walkie-talkie using a single Arduino board. The circuit described in the link you provided uses a single Arduino board to transmit and receive messages.

To make the walkie-talkie work, you will need to connect the Arduino board to a transmitter and receiver module, such as a nRF24L01 module. The transmitter module will be used to send the messages, and the receiver module will be used to receive the messages. You can then use the Arduino's serial communication functions to send and receive messages via the transmitter and receiver modules.

If you want to make multiple walkie-talkies, you will need to build a separate circuit for each one using an Arduino board and the necessary transmitter and receiver modules. You will also need to program each Arduino board separately to transmit and receive messages.

I hope this helps. Let me know if you have any further questions.