Yesterday I gave free rein to the imagination and knowledge of Arduino and I mounted my castle shield to make a data logger with Arduino
The project itself is not complex less than familiar with some concepts such as I2C and SPI, In fact, I decided to use a shield SD Card to write my data to an SD card 64GB, more than sufficient for some line of log in a text file, and an RTC to maintain the time of acquisition of the log.
Proceed in order starting from the material needed for the project data logging with Arduino:
- 1 Arduino Uno
- 1 RTC Shield or another based on RTC DS1307
- n.1 SD Card shield
- # 5 buttons n.a. ( normally open )
- # 5 330ohm resistors
- n.1 breadboard
- for some cable connections
Defined the material must bear in mind that the RTC used as the communication protocol I2C Bus ie pin SDA ( pin A4 ) and SCL ( pin A5 ) Arduino, Shield some have the possibility to use the 2 additional pins SDA and SCl present on the Arduino Uno R3, however, these pins are connected, level arduino, to the same pin A4 and A5, for which the corresponding Analog inputs are still usable.
The scield SD card using the SPI bus consists of the pins:
D13 SD_CLK
D12 SD_OUT
D11 SD_IN
D10 SD_CS
in addition to 3.3v and Gnd, some SD card used as pin CS pin 4, is the case of Ethernet Shield Journal Arduino that in addition to the pins 13,12,11 use the pin 4 come CS.
The circuit data logging with Arduino
To connect the Arduino shield, you should not use it if it, as I did, the shield stacked to make your data logging, the only connections to concern 5 buttons that are connected as usual through a pull-down ( to Gnd ) da 330ohm.
The first 4 buttons, use them to simulate the change of data on inputs A0, A1, A2 and A3 and the fifth button will use it to indicate that you want to reload the sketch and read the file on the SD Card, I call it READ button, here is a picture of the buttons
and one of the connections to the analog inputs
while the fifth button ( Read ) you must connect to pin 9 data logging with arduino
Operation of the data logging
The data logging with Arduino is an experiment, so I decided to use the 4 buttons to simulate the change of values detected by the ADC ( analog to digital converter ) Arduino, considers that each value converted by the ADC sull'Arduino One can vary from 0 a 1023 ( 10bit ) and will be 0 when the button is not pressed through a 1023 when you press one of the buttons.
The data logging simultaneously write to the log file and the monitor serial data collected from 4 analog pin in addition to the date and time at which the data was collected.
You can replace each of the 4 buttons with the sensor you see fit, I deliberately used the analog inputs to allow you to be able to detect 1024 signal levels from each pin, if you used the pin digital I could only detect the transition from LOW to HIGH state is and vice versa.
Download sketch del data logging
You can download the sketch and the RTC library that I used for this project directly from GitHub.
The sketch of the data logging
// Date and time functions using a DS1307 RTC connected via I2C and Wire lib
#include <Wire.h>
#include "RTClib.h"
#include <SD.h>
#define readButton 9
#define CS 10
RTC_DS1307 RTC;
char buffer[40];
File myFile;
void setup () {
Serial.begin(57600);
Serial.print("Initializing SD card...");
pinMode(CS, OUTPUT);
pinMode(readButton, INPUT);
if (!SD.begin(CS)) {
Serial.println("initialization failed!");
return;
}
Serial.println("initialization done.");
Wire.begin();
RTC.begin();
RTC.sqw(1); //0 Led off - 1 Freq 1Hz - 2 Freq 4096kHz - 3 Freq 8192kHz - 4 Freq 32768kHz
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__));
}
}
void loop () {
DateTime now = RTC.now();
sprintf(buffer, "%02d/d/%d d:%02d:%02d %d %d %d %d", now.day(), now.month(), now.year(), now.hour(), now.minute(), now.second(), analogRead( A0 ), analogRead( A1 ), analogRead( A2 ), analogRead( A3 ) );
Serial.println( buffer );
myFile = SD.open("dati.log", FILE_WRITE);
if (myFile) {
myFile.println(buffer);
myFile.close();
} else {
Serial.println("error opening dati.log");
}
if ( digitalRead( readButton ) == HIGH ) {
Serial.println(" ");
Serial.println("Log Reading Saved ----------- ");
Serial.println(" ");
myFile = SD.open("dati.log");
if (myFile) {
while (myFile.available()) {
Serial.write(myFile.read());
}
myFile.close();
}
delay( 5000 );
}
delay(1000);
}
the sketch of the data logging includes both classes needed to communicate with the RTC and those to use the SD Card shield:
lines 03-04: Wire include the class and the class to communicate with the RTC DS1307 through the I2C protocol;
line 05: include the class to read and write to the SD Card with SD SPI protocol;
lines 07-08: define in which pins you have connected the button you will use to re-read the log data logging and pin CS that your SD Card uses;
line 10: initializes the RTC;
line 11: define a buffer in which to memorize the time and the detected values. To calculate the length of the buffer can count the maximum number of characters that may contain, you know that the date is made 10 characters ( gg / mm / aaaa ) and time to 8 characters ( hh:mm:ss ) and that between the two there is a space, then you know that each value is separated by a space to allow you to easily read and the highest value of each pin is 1023 ( 4 characters ) for which the calculation is: 10 + 1 + 8 + 1 + 4 + 1 + 4 + 1 + 4 + 1 +4 = 39 for which you can define the buffer 40 ( considering a margin of 1 value )
lines 16-17: sets the communication with the serial monitor 57600 baud and write on the serial monitor the string “Inizializing SD card …”
lines 18-19: sets the operation mode to the CS pin and the pin connected to the button reading ( pin 9 );
lines 21-24: initializes the object with the SD method begin and passing the value of the pin CS, if it fails to initialize the SD Card writes the serial monitor “Initialization failed” and exits the setup function using the command return;
lines 27-34: Wire and initializes the RTC, tax 1 according to the flashing frequency of the SQW LEDs present on the RTC Shield and if time is not configured sets the current time of the RTC Pc, for the procedure read the article Tutorial: RTC Shield con DS1307;
line 38: sets an instance of type DateTime as RTC.now();
line 40: compose the line buffer using the command sprintf( buffer, format, val1, val2 ….walnuts ) where buffer is the variable in which to store the entire string, the format is that of the command sprintf ( see manual ), and subsequent values are the ones you want to buffer;
line 41: write the serial monitor the value of buffer;
line 43: Open the file in write mode “dati.log” on the SD Card data logging
lines 44-46: if the file pointer dati.log there, ie if you are unable to open communication with the SD card inserted in the SD Card Shield write the string buffer and close the file;
lines 47-49: in the event of failure to open a file dati.log write the string on the serial monitor “error opening dati.log”;
line 51: check that the value detected on pin buttonRead is HIGH means that the pushbutton connected to this pin has been pressed;
lines 52-54: write a blank line on the serial monitor, la stringa “Log Reading Saved ————–” and an additional blank line, only serves to separate lines written by the normal operation from those read from the SD Card of the data logging;
line 55: open the file dati.log in read mode, In fact you do not specify any parameters as the second argument of the method open;
lines 56-61: If the file has been successfully opened read line by line the log file and write the result of each line on the serial monitor;
line 62: set a delay 5 second ( 5000 milliseconds ) before returning to normal operation log;
line 65: sets a delay of 1 second between one cycle of the function loop() and the following.
The video data logging with Arduino
In order to show how the data logging you just realized you can watch the video that I made during my test with data logging:
Log good !!!
15 comments
4 pings
Jay
26 January 2013 at 17:54 (UTC 2) Link to this comment
Great demo. How would you recommend uploading this data to an FTP site so that it could be graphed in a web page?
Mauro Alfieri
28 January 2013 at 13:08 (UTC 2) Link to this comment
Thank you,
i suggest you use an Ethernet connection.
Mauro
Henry
29 January 2013 at 16:55 (UTC 2) Link to this comment
Congratulations for the tutorial, reading it gave me the inspiration and I would like to create a data logging with one arduino r3 recording data (text strings) coming through serial rs232 by a GPS and an echo sounder on the sd card.
By connecting the GPS (baudrate 9600) and sounding (baudrate 4800) to the serial port of the PC with hyperterminal see text strings.
For now I am recording the data with a laptop and a data logging software but rather, as a matter of size and portability, use a solution with arduino.
Do you think that using the shield Assembled Adafruit Data Logging and two Serial Interface RS232-TTL 3 to 5.5 V is able easily or will I need a different hardware configuration?
Henry
Mauro Alfieri
30 January 2013 at 16:10 (UTC 2) Link to this comment
Hello Henry,
thanks for the compliments.
The shield Assembled Adafruit Data Logging has within it both the shield and the RTC SD Card, might be a good solution, I've never tried because I do not own one and I can not tell if it's easier or more difficult to achieve DataLogging.
You know that Arduino has only one serial that already use to upload sketches, of course you can use it for the data logger when it is separated from the computer, two 2 serial-to-read, at different speeds, you can try simulating the serial library SoftwareSerial.h (see tutorial Blog ) or use a Arduino Mega that has 4 independent serial.
Mauro
rise
4 February 2013 at 18:45 (UTC 2) Link to this comment
i want generate arduino data logging based bar code scanner. do have a link?
Mauro Alfieri
5 February 2013 at 09:01 (UTC 2) Link to this comment
No, I do not have links to suggest
Mauro
Paul Furley
11 February 2013 at 12:48 (UTC 2) Link to this comment
Neat project and great write-up, thanks for the detail. I imagine this could be quite a disruptive application as commercial data loggers don’t come cheap. Might be fun to do a radiation level logger with the Geiger counter shield
Paul
Mauro Alfieri
11 February 2013 at 15:01 (UTC 2) Link to this comment
Hi Paul,
you can try a project if you have a counter Gaiger available.
Mauro
Danny
18 February 2013 at 22:35 (UTC 2) Link to this comment
Please check line 50. Seems incorrect. Should be:
if(digitalRead(readButton) == HIGH){
Good tutorial. Appreciate that you are sharing with us.
Thanks!
Mauro Alfieri
19 February 2013 at 10:12 (UTC 2) Link to this comment
Thanks for your report, I see no difference between line.
Mauro
Francis
3 May 2013 at 00:04 (UTC 2) Link to this comment
Hello,
thanks to your information I was able to assemble the various components such as LCD, RTC, SD module and temperature sensors. This all works perfectly, but I wanted to make a change to the data logger, I would like the file with the recorded data is created every day with a different name, perhaps with the date of the day of registration (this is. 03_05_2013.txt). Can you kindly help me out?
Thanks
Francis
Mauro Alfieri
3 May 2013 at 13:27 (UTC 2) Link to this comment
Hello Francesco,
is a modification of a bit’ challenging but not impossible.
You can work with the shakes and set a different file name for each day.
Remember to check that the file exists before writing values, This device prevents the passage of midnight the new file is not present so you should always check that the file exists and you want to write to create it in case there is already
Mauro
mrss
21 May 2013 at 10:38 (UTC 2) Link to this comment
Hi there,
I would like to know your recommendation (since I am very new to Arduino), if I want to log some data, say it I sample it every 1 sec, and when it reaches 60 sec, it will average the 60 data, and log it to the SD card for every 1minute, how am I going to do that? I am very confuse now.
I manage to log the data every sec. It means in my SD card, every sec of data has been logged. But the problem is now, I only want to log data for every 1 min after averaged all the 60 sec data. Meaning that in my SD card only has data for every 1 minute. Do you understand me? Thank you in advance for your quick response. I am very looking forward for it. Thank you!
Mauro Alfieri
22 May 2013 at 07:32 (UTC 2) Link to this comment
hello najwa,
i understand your project.
You store values into a variable 60 times per minute and average:
for( int i=0;i<=60;i++) {
int val=analogRead( your_pin );
valTotal += val;
delay( 1000 );
}
valTotal = ( valTotal / 60 );
then write valTotal to the SD card.
Mauro
mrss
29 May 2013 at 05:16 (UTC 2) Link to this comment
thank you mauro!
now i got the idea! thanks!
Mrss
Arduino Blog » Blog Archive » Data-logging made simple with Arduino
23 January 2013 at 21:01 (UTC 2) Link to this comment
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24 January 2013 at 17:47 (UTC 2) Link to this comment
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