**2.2 Microcontroller**

Arduino Nano is a complete small microcontroller board that supports the use of PCB boards. Arduino Nano is based on the Atmel AVR microcontrollers. This microcontroller is open source with Arduino Language programming language, which resembles C++. The Arduino Nano doesn't include a barrel jack, but it connects to a computer using the MiniB USB connector. Arduino Nano is equipped with 8 analog pins and 22 digital pins (6 of which is PWM pin) with 16 MHz of clock speed. **Figure 1** shows the shape of the Arduino Nano.

#### **2.3 Adapter microSD card module**

This microSD card adapter module is a microSD card reader module. Through the file system and SPI driver interface, the MCU completes the file system read and write operations of the microSD card. Arduino users can directly use the Arduino IDE,

**Figure 1.** *Arduino Nano.*

**Figure 2.** *MicroSD card module.*

which is equipped with an SD card. The figure of the microSD card module is shown in **Figure 2**.

This communication model is indeed more wasteful in terms of the use of data lines, but it is safer when synchronizing data between data sent from the signal processing module and data received by the data storage module. This is because this model uses synchronous communication with a single clock source originating from the Arduino Nano module. In this study, the data is stored in the form of text files on a microSD card with a capacity of 4 GB. The pins between the Arduino and the microSD card module are VCC to 5 V, GND to ground, Mosi to pin 11, Miso to pin 12, SCK to pin 13, CS to pin four from Arduino.
