I have designed and wrote a program to monitor temperature and humidity 2 months ago. It took me another a month to publish it. Why? Because I can not find any suitable circuit sketch for Arduino. And lazy. Hehhe.
So, what I can give to the other people about my latest project is only in short description. Any problem/questions, just ask me in comment down below using Facebook.
Objective: Build a system using Arduino to monitor temperature and humidity and save it in memory card.
Part:
1.Arduino (whatever you have. Mine, not the latest one).
2.Arduino RTC (real time clock) v1.1. To read date/time.
3.Humidity & temperature sensor DHT11
4.SD card reader/write from LC studio, www.lcsoft.net
5.SD card
6.Some wire jumpers, if needed. I need a lot of them.
Design:
Just view it from here.
Program?
#include <SD.h>
#include "RTClib.h"
#include <Wire.h>
#include <string.h>
#include <dht11.h>
#include <stdlib.h>
RTC_DS1307 RTC;
int delaytime= 3000;
dht11 DHT11;
#define DHT11PIN 2
File myFile;
void setup()
{
Serial.begin(9600);
Wire.begin(); //Important for RTClib.h
RTC.begin();
if (! RTC.isrunning()) {
Serial.println("RTC is NOT running!");
// following line sets the RTC to the date & time this sketch was compiled
// RTC.adjust(DateTime(__DATE__, __TIME__));
return;
}
Serial.print("Initializing SD card...");
// On the Ethernet Shield, CS is pin 4. It's set as an output by default.
// Note that even if it's not used as the CS pin, the hardware SS pin
// (10 on most Arduino boards, 53 on the Mega) must be left as an output
// or the SD library functions will not work.
pinMode(10, OUTPUT);
if (!SD.begin(4)) {
Serial.println("initialization failed!");
return;
}
Serial.println("initialization done.");
}
void loop()
{
openFile();
writeFile();
closeFile();
delay(delaytime);
}
void openFile(){
char filename[] = "00000000.CSV";
DateTime now = RTC.now();
filename[0] = (now.year()/1000)%10 + '0'; //To get 1st digit from year()
filename[1] = (now.year()/100)%10 + '0'; //To get 2nd digit from year()
filename[2] = (now.year()/10)%10 + '0'; //To get 3rd digit from year()
filename[3] = now.year()%10 + '0'; //To get 4th digit from year()
filename[4] = now.month()/10 + '0'; //To get 1st digit from month()
filename[5] = now.month()%10 + '0'; //To get 2nd digit from month()
filename[6] = now.day()/10 + '0'; //To get 1st digit from day()
filename[7] = now.day()%10 + '0'; //To get 2nd digit from day()
//Check file name exist?
if (SD.exists(filename)) {
Serial.println("exists.");
myFile = SD.open(filename, FILE_WRITE);
}
else {
Serial.println("doesn't exist.");
Serial.println("Creating new file");
myFile = SD.open(filename, FILE_WRITE);
}
}
void writeFile(){
DateTime now = RTC.now();
myFile.print(now.year(),DEC);
myFile.print("/");
myFile.print(now.month(),DEC);
myFile.print("/");
myFile.print(now.day(),DEC);
myFile.print(" ");
myFile.print(now.hour(),DEC);
myFile.print(":");
myFile.print(now.minute(),DEC);
myFile.print(":");
myFile.print(now.second(),DEC);
myFile.print(",");
DHT11.read(DHT11PIN);
myFile.print((float)DHT11.temperature, 2);
Serial.println((float)DHT11.temperature, 2);
myFile.println((float)DHT11.humidity, 2);
Serial.println((float)DHT11.humidity, 2);
}
void closeFile(){
myFile.close();
}
The output in SD card must Date/Time; Temperature ; Humidity.