Using a Datalogger With Arduino

 

HiLetgo Data Logger Module Logging Shield Data Recorder Shield for Arduino UNO w/SD Card

Arduino Library: SD https://www.arduino.cc/reference/en/libraries/sd/

Set CS Chip select to 10 (default is 4)

Tutorial: https://maker.pro/arduino/tutorial/how-to-log-temperature-humidity-heat-data-with-arduino-to-sd-card

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#include "DHT.h"

#include <SD.h>

#define DHTPIN 8

#define DHTTYPE DHT22

const int chipSelect = 10;

DHT sensor(DHTPIN, DHTTYPE);

void setup()

{

Serial.begin(9600);

sensor.begin();

Serial.print("Initializing SD card...");

if (!SD.begin(chipSelect)) {

Serial.println("Card failed, or not present");

// don't do anything more:

return;

}

Serial.println("card initialized.");

}

void loop()

{

float humidity = sensor.readHumidity();

float temperature_C = sensor.readTemperature();

float temperature_F = sensor.readTemperature(true);

if (isnan(humidity) || isnan(temperature_C) || isnan(temperature_F)) {

Serial.println("Failed to read from DHT sensor!");

return;

}

float heat_indexF = sensor.computeHeatIndex(temperature_F, humidity);

float heat_indexC = sensor.convertFtoC(heat_indexF);

File sdcard_file = SD.open("data.txt", FILE_WRITE);

// if the file is available, write to it:

if (sdcard_file) {

sdcard_file.print("Temperature in C: ");

sdcard_file.print(temperature_C);

sdcard_file.print(" Temperature in Fah: ");

sdcard_file.print(temperature_F);

sdcard_file.print(" Humidity: ");

sdcard_file.print(humidity);

sdcard_file.print(" Heat Index in F: ");

sdcard_file.print(heat_indexF);

sdcard_file.print(" Heat Index in C: ");

sdcard_file.println(heat_indexC);

sdcard_file.close();

// print to the serial port too:

Serial.print("Temperature in C: ");

Serial.print(temperature_C);

Serial.print(" Temperature in Fah: ");

Serial.print(temperature_F);

Serial.print(" Humidity: ");

Serial.print(humidity);

Serial.print(" Heat Index in F: ");

Serial.print(heat_indexF);

Serial.print(" Heat Index in C: ");

Serial.println(heat_indexC);

}

// if the file isn't open, pop up an error:

else {

Serial.println("error opening datalog.txt");

}

delay(1000);

}