Hello,
Today I would like to share with you my second little project. Its an Arduino temperature logger which saves data on micro SD card and thanks to a short Python script it can also send data to Ubidots IOT application. The circuit itself is very simple, in order to complete it all you need is:
11 - jumper wires
1 - 4.7K ohm resistor
1 - DS18B20 temperature sensor
1 - SD card reader
1 - Arduino UNO
Here's the circuit's schematic:
Here's a video showing how assemble the circuit:
Arduino sketch for this project:
#include <OneWire.h> //library for communication with temperature sensor
#include <DallasTemperature.h> //temperature sensor library
#include <SD.h> //sd card reader library available in every Arduino IDE
#include <SPI.h> //library for communication with SD card reader
// Data wire is plugged into port 2 on the Arduino
#define ONE_WIRE_BUS 2
// Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
OneWire oneWire(ONE_WIRE_BUS);
File logs; // variable responsible for writing to file
float temp; //variable storing the current temperature
int number = 0; //variable holding the number indicating current entry in csv file
unsigned int hour = 20; //variable storing current hour
unsigned int minute = 45; //variable storing current minute
unsigned int day = 2; //variable storing current day of the week
unsigned int date = 15; //variable storing current day of the month
unsigned int month = 12; //variable storing current month
unsigned int year = 2015; //variable storing current year
unsigned int leap_year = 0; //variable for checking whether it's a leap year or not
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);
void setup(void)
{
// start serial port
Serial.begin(9600);
SD.begin(10);
// Start up the library
sensors.begin();
} //end of void setup
void loop(void)
{
//checking whether it's leap year or not
if (year % 4 == 0)
leap_year = 1;
else
leap_year = 0;
//changing minutes
if (minute < 55)
minute +=5;
else
minute = 0;
//changing hour
if ((minute == 0) && (hour < 24))
hour++;
if ((minute == 0) && (hour == 24))
hour = 0;
//changing day of the week
if((minute == 0) && (hour == 0) && (day <8))
day +=1;
if((minute == 0) && (hour == 0) && (day == 8))
day = 1;
//changing day of the month
//formula for 30 day months
if ((date < 31) && ( (month == 4) || (month == 6) || (month == 9) || (month == 11)) && (hour == 0) && (minute ==0))
{
date++;
}
if ((date == 31) && ( (month == 4) || (month == 6) || (month == 9) || (month == 11)) && (hour == 0) && (minute ==0))
{
date = 0;
month++;
}
//formula for February
if ( ((date < 29) && (month == 2) && (hour == 0) && (minute == 0) && (leap_year == 0)) || ((date < 30) && (month == 2) && (hour == 0) && (minute == 0) && (leap_year == 1)) )
{
date = date +1;
}
if ( (date == 29) && (month == 2) && (hour == 0) && (minute == 0) && (leap_year == 0) || ((date == 30) && (month == 2) && (hour == 0) && (minute == 0) && (leap_year == 1)) )
{
date = 0;
month = 3;
}
//formula for 31 day months
if ((date < 32) && ( (month == 1) || (month == 3) || (month ==5) || (month == 7) || (month == 8) || (month == 10) || (month == 12)) && (hour == 0) && (minute ==0))
{
date++;
}
if ((date == 32) && ( (month == 1) || (month == 3) || (month ==5) || (month == 7) || (month == 8) || (month == 10) || (month == 12)) && (hour == 0) && (minute ==0))
{
date = 1;
if(month <12)
month++;
else
month = 1;
}
//changing year
if( (hour == 0) && (minute == 0) && (date == 1) && (month == 1))
year++;
sensors.requestTemperatures(); // Send the command to get temperatures
temp = sensors.getTempCByIndex(0); //assigning sensor's vale to the variable
Serial.println(temp);
logs = SD.open("logs.csv", FILE_WRITE); //assigning file to which we want to write the data
if(logs) //if opening of the file was successful
{
if (number == 0)
logs.println("sep=,"); //we add this line to the file so that excel 2013 and newer software knows that this is coma separated file
//then we write entry number, date and sensor read
logs.print(number);
logs.print(",");
logs.print(temp); //finally we add temperature read from sensor
logs.print(",");
if (hour < 10)
logs.print("0"); //we add 0 is hour is lower than 10
logs.print(hour);
logs.print(":");
if(minute <10)
logs.print("0"); //we add 0 if minute is lower than 10
logs.print(minute);
logs.print(" ");
switch(day) //we add day of the week appropriately
{
case 1:
logs.print("Monday");
break;
case 2:
logs.print("Tuesday");
break;
case 3:
logs.print("Wednesday");
break;
case 4:
logs.print("Thursday");
break;
case 5:
logs.print("Friday");
break;
case 6:
logs.print("Saturday");
break;
case 7:
logs.print("Sunday");
break;
}
logs.print(" ");
logs.print(date);
logs.print(" ");
switch(month)
{
case 1:
logs.print("January");
break;
case 2:
logs.print("February");
break;
case 3:
logs.print("March");
break;
case 4:
logs.print("April");
break;
case 5:
logs.print("May");
break;
case 6:
logs.print("June");
break;
case 7:
logs.print("July");
break;
case 8:
logs.print("August");
break;
case 9:
logs.print("September");
break;
case 10:
logs.print("October");
break;
case 11:
logs.print("November");
break;
case 12:
logs.print("December");
break;
}
logs.print(" ");
logs.println(year); //printing year to the file
Serial.println("Saving successful");
logs.close();//we close and save the file
}
logs.flush();
delay(300000); // we delay program for 5 minutes and then take another read
//delay(60000); //for testing purposes 1 minute
//delay(2000);//for testing purposes 2 seconds
number = number + 1; // we add 1 to the entry counter
}
Python script which allows communication between Arduino and Ubidots application:
from ubidots import ApiClient #importing ubidots api
from time import * #importing standard time library
import serial #importing pyserial library
api = ApiClient ('your_account_key') #key of our ubidots account
ser = serial.Serial('COM6', 9600, timeout = 0) #establishing communication with Arduino serial port
temp_val = api.get_variable('your_variable_key') #ubidots variable's key with which we want to communicate
while True:
current_temp = ser.readline(6) #reading first 6 characters from serial port
if ( (current_temp[:1] == '-')or(current_temp[:1] == '1') or (current_temp[:1] == '2') or (current_temp[:1] == '3') or (current_temp[:1] == '4') or (current_temp[:1] == '5') or (current_temp[:1] == '6') or (current_temp[:1] == '7') or (current_temp[:1] == '8') or (current_temp[:1] == '9') ):
float_current_temp = float(current_temp[:5]) #converting value read from the serial port a float
new_value = temp_temp.save_value({'value':float_current_temp}) #sending value to ubidots
print ("sending successful")
Video explaining Arduino sketch and Python script, as well as providing introduction to Ubidots:
Please comment. Any feedback is very valuable for me, especially constructive criticism. If you like what I'm doing you can subscribe my channel on YouTube (https://www.youtube.com/user/W0j45), follow me on Twitter (https://twitter.com/milczarekw) and Instagram (https://www.instagram.com/milczarekw/).
Thank you for reading!
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