Circuit Documentation

Summary of the Circuit

This circuit is designed to capture voltage data from a piezo sensor and log this data to a file on an SD card. The piezo sensor is interfaced with an Arduino Nano microcontroller, which reads the sensor's voltage and writes the data to the SD card using a Micro SD Card Module. The data logging occurs at a rate of 10 samples per second. The Arduino Nano communicates with the SD card module via the SPI (Serial Peripheral Interface) protocol.

Component List

Piezo Sensor

• Description: A sensor that generates a voltage when it is deformed by pressure or vibration.
• Pins:
  • +: Positive terminal
  • -: Negative terminal

Arduino Nano

• Description: A small, complete, and breadboard-friendly microcontroller board based on the ATmega328P.
• Pins:
  • Digital I/O Pins: D0 - D13
  • Analog Input Pins: A0 - A7
  • Power Pins: 3V3, 5V, GND, VIN
  • SPI Pins: D11/MOSI, D12/MISO, D13/SCK
  • Other Pins: RESET, AREF

Micro SD Card Module

• Description: A module that allows microcontrollers to interface with a micro SD card using SPI for data storage.
• Pins:
  • cs: Chip Select
  • sck: Serial Clock
  • mosi: Master Out Slave In
  • miso: Master In Slave Out
  • vcc: Power supply
  • gnd: Ground

Wiring Details

Piezo Sensor

• + (Positive terminal) is connected to GND on the Arduino Nano.
• - (Negative terminal) is connected to A0 on the Arduino Nano.

Arduino Nano

• A0 is connected to the negative terminal of the Piezo Sensor.
• GND is connected to the positive terminal of the Piezo Sensor and gnd on the Micro SD Card Module.
• 5V is connected to vcc on the Micro SD Card Module.
• A6 is connected to cs on the Micro SD Card Module.
• A5 is connected to sck on the Micro SD Card Module.
• D12/MISO is connected to miso on the Micro SD Card Module.
• D11/MOSI is connected to mosi on the Micro SD Card Module.

Micro SD Card Module

• cs is connected to A6 on the Arduino Nano.
• sck is connected to A5 on the Arduino Nano.
• mosi is connected to D11/MOSI on the Arduino Nano.
• miso is connected to D12/MISO on the Arduino Nano.
• vcc is connected to 5V on the Arduino Nano.
• gnd is connected to GND on the Arduino Nano.

Documented Code

/*
 * This Arduino sketch reads voltage data from a piezo sensor connected to A0
 * and stores the data in a file on an SD card. The SD card module is connected
 * to the Arduino Nano via SPI interface. The Arduino reads the piezo sensor
 * voltage 10 times per second and logs the data to the SD card.
 */

#include <SPI.h>
#include <SD.h>

const int piezoPin = A0; // Pin connected to the piezo sensor
const int chipSelect = A6; // Pin connected to the SD card module's CS pin

File dataFile;

void setup() {
  Serial.begin(9600);
  pinMode(piezoPin, INPUT);
  if (!SD.begin(chipSelect)) {
    Serial.println("SD card initialization failed!");
    return;
  }
  Serial.println("SD card initialized.");
  dataFile = SD.open("datalog.txt", FILE_WRITE);
  if (!dataFile) {
    Serial.println("Error opening datalog.txt");
  }
}

void loop() {
  int sensorValue = analogRead(piezoPin);
  if (dataFile) {
    dataFile.println(sensorValue);
    dataFile.flush();
  } else {
    Serial.println("Error writing to datalog.txt");
  }
  delay(100); // Delay for 100 milliseconds (10 readings per second)
}

The code is written for an Arduino Nano and is responsible for initializing the SD card, reading the voltage from the piezo sensor, and logging the data to a file named "datalog.txt" on the SD card. The setup() function initializes the serial communication, sets up the piezo sensor pin as an input, and prepares the SD card for data logging. The loop() function reads the sensor value and writes it to the SD card every 100 milliseconds.