*7.2. Hardware Implementation*

The encryption algorithm is applied to a signal between (0 Hz–200 Hz) based on two microcontroller boards of Arduino Uno R3. The properties of these boards are non-expensive, have a simple design, and powerful microcontrollers that depend on the ATmega328 chip. The input and output pins are digital which consists of 14 digits, six of them are used as pulse width modulation (PWM) outputs, the other six are analog inputs. Besides that, the other 2 digits are used as 16 MHz crystal oscillator, the USB connection, and a reset button. These materials can be implemented by utilizing the C++ language. The computer with specification Core i3- 2.00 GHz, Intel CPU, and RAM 4 GB is used to run the software that is designed by the C++/C programing language, which is used to implement the two Arduino boards. These experiments have been implemented in a lab using a 200 MHz digital oscilloscope and a digital function generator. It is shown in Figure 16.

**Figure 16.** Work environment and laboratory materials.

The experiment was conducted in the laboratory. The results presented in Figure 17a refers to the sent message that appears in blue, while the retrieved message appears in yellow, and Figure 17a refers to the serial binary data.

**Figure 17.** Oscilloscope outputs: (**a**) the sent message appeared in blue, and the reconstructed message appeared in yellow; (**b**) the serial data.
