![\"\"](\"https:\/\/i0.wp.com\/lallafa.de\/blog\/wp-content\/uploads\/2012\/11\/datalog.jpg\" "\\"datalogger\\"")
<\/a>Arduino and Logger Shield: Temperature Logger<\/p><\/div>\n
The logger samples the temperature every 10s and gives you a digital temperature value with +\/-0.5 degree Celsius precision. It has a RTC (real-time-clock) on board that time stamps every measurement. Addionally, the SD card allows you to store the temperature samples in log files.<\/p>\n
The logger has two modes of operation: Either directly read the temperature via a Mac\/PC connected via the virtual serial port available on USB or write a temperature log onto the SD card. The latter mode allows you to use the device stand alone in any room without the need to directly connect your computer.<\/p>\n
Read on for the full build and usage instructions…<\/p>\n
1. Hardware<\/h3>\n
You need:<\/p>\n
- \n
- an Arduino board (I use an Arduino 2009<\/a> but UNO will be fine, too)<\/li>\n
- an Adafruit Logger Shield<\/a><\/li>\n
- a push button (to toggle SD card recording)<\/li>\n
- a DS18S20 digital temperature sensor<\/li>\n
- 2 1k resistors<\/li>\n<\/ul>\n
Use the prototyping area of the Logger Shield to attach the push button and the DS18S20. The following fritzing.org<\/a> schematic shows you the required connections:<\/p>\n
![\"\"](\"https:\/\/i0.wp.com\/lallafa.de\/blog\/wp-content\/uploads\/2012\/11\/datalog.png?resize=480%2C473\" "\\"datalog\\"")
<\/a>Note: the LEDs and the associated resistors are already available on the logger shield. You only have to connect them to the Arduino on DIGITAL 3 and DIGITAL 4 pins. The LED pins have connectors right beside the two DIGITAL ports. So two small wire bridges will connect them. The push button is connected to DIGITAL 2 and the temperature sensors data channel to DIGITAL 7. The temperate one-wire bus needs a 1k pull up to 5V while the push button uses a 1k pull down resistor.<\/p>\nHere is a summary of the connected digital ports:<\/p>\n
- \n
- DIGITAL 2: push button input<\/li>\n
- DIGITAL 3: LED (green) output<\/li>\n
- DIGITAL 4: LED (red) output<\/li>\n
- DIGITAL 7: temperature sensors DS18S20 DQ data channel<\/li>\n<\/ul>\n
That’s it for the hardware… and don’t forget to add a battery for the RTC (real time clock).<\/p>\n
2. Software<\/h3>\n
2.1 Firmware<\/h4>\n
The firmware is hosted on my github site:<\/p>\n
- \n
- GitHub: ardu.git<\/a><\/li>\n
- \n
git clone git:\/\/github.com\/cnvogelg\/ardu.git<\/pre>\n<\/li>\n<\/ul>\n
Simply clone this repository and have a look in the datalog<\/strong> directory:<\/p>\n
The file datalog.ino<\/strong> is an Arduino IDE<\/a> sketch you can directly open there.<\/p>\n
Note:<\/strong> the sketch requires the RTC and SD FAT FS library that is available at Ladyada for the Logger Shield: see the Logger Shied Download<\/a> page for details and install the libraries first!<\/p>\n
Open the sketch and flash it on your device…<\/p>\n
2.2 Configuration<\/h4>\n
Before you can use the data logger you have to configure it:<\/p>\n
- \n
- In the Arduino IDE open the serial monitor<\/strong> (Tools -> Serial Monitor) with 57000 Baud<\/strong> and Line Ending Both NL+CR<\/strong><\/li>\n
- Insert a FAT formatted SD card and power the device<\/li>\n
- If the green LED is enabled then everything is fine and SD and temperature sensor was detected. You can see the serial number of your sensor:<\/li>\n<\/ul>\n
DS18S20: 10 83 B4 8D 2 8 0<\/pre>\n
- \n
- If the red LED blinks then an error has occurred:\n
- \n
- Either the sensor was not detected:<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
FATAL: ADDR?\r\n<\/pre>\n
- \n
- \n
- \n
- Or the SD card was not found:<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
FATAL: SD\r\n<\/pre>\n
- \n
- \n
- \n
- In both cases have a look at your wiring or your card to fix this…<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
Now we are ready to set up the RTC (real time clock):<\/p>\n
- \n
- You can enter commands in the Serial Monitor and send them to the device<\/li>\n
- The following commands are supported:\n
- \n
- ‘r’ – read clock (load time and date from RTC chip and print it)<\/li>\n
- ‘a’ – adjust clock (save the current values for year, month, day, hour, minutes, seconds to RTC chip)<\/li>\n
- ‘y’ <nnnn> – set year: 2012 …<\/li>\n
- ‘m’ <nn> – set month: 01 .. 12<\/li>\n
- ‘d’ <nn> – set day of month: 01 .. 31<\/li>\n
- ‘H’ <nn> – set hour: 00 .. 23<\/li>\n
- ‘M’ <nn> – set minute: 00 .. 59<\/li>\n
- ‘S’ <nn> – set seconds: 00 .. 59<\/li>\n
- ‘o’ – open log on SD card for writing<\/li>\n
- ‘c’ – close open log on SD card and stop writing<\/li>\n
- ‘D’ <nnnn> – interval of measurements in seconds. default: 10s<\/li>\n<\/ul>\n<\/li>\n
- So for setting up the clock to: 28.11.2012 18:34:20<\/strong> you would enter:<\/li>\n<\/ul>\n
y2012\r\nm11\r\nd28\r\nH18\r\nM34\r\nS20\r\na\r\n<\/pre>\n
- \n
- Now your RTC is set up and you should see incoming measurements like this one<\/li>\n<\/ul>\n
t: 2012.11.18 19:39:03 50A93957 +024.50 0189\r\nt: 2012.11.18 19:39:13 50A93961 +024.50 0189\r\nt: 2012.11.18 19:39:23 50A9396B +024.50 0188<\/pre>\n
- \n
- Each line has the following columns:\n
- \n
- date and time<\/li>\n
- raw date and time in hex<\/li>\n
- temperature value in degree celsuis<\/li>\n
- raw temperature value in hex<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
3. Stand-alone operation<\/h3>\n
Start Logging:<\/p>\n
- \n
- Detach the Arduino from your Mac\/PC<\/li>\n
- Use a USB power-supply to power the logger now<\/li>\n
- Make sure the green LED is enabled after power on (SD card is attached and sensor is OK).<\/li>\n
- Now press the push button<\/strong> to start the logging operation<\/li>\n
- The red LED is enabled and shows you that data is written to SD card<\/li>\n
- Each time the green LED blinks a measurement is taken and written to the log file<\/li>\n<\/ul>\n
End Logging:<\/p>\n
- \n
- After a while stop logging by pressing the push button again<\/li>\n
- The red LED now is disabled and logging has stopped<\/li>\n
- Now you can safely remove the SD card and have a look at your data<\/li>\n
- Note:<\/strong> do never remove the SD card while the red LED is on this might corrupt your data on the card!<\/li>\n
- On the SD card a data file is always named yymmdd_s.LOG<\/strong> with yymmdd being the current date and s a letter starting from A that is incremented with every new log<\/li>\n<\/ul>\n
4. Plot a Temperature Graph<\/h3>\n
You can now use your favorite spread sheet application or graphing tool to convert the data log files from the SD card to pictures.<\/p>\n
In my code repository I have written a small Python script that uses rrdtool<\/a> to plot the graphs (see datalog\/tools\/plot_log.py<\/a>):<\/p>\n
Run it as follows:<\/p>\n
python2.7 plot_log.py .\/plot_log.py 121104_A.LOG out.png<\/pre>\n
This will create an image like this:<\/p>\n
![\"\"](\"https:\/\/i0.wp.com\/lallafa.de\/blog\/wp-content\/uploads\/2012\/11\/out2-300x91.png?resize=584%2C177\" "\\"out2\\"")
<\/a><\/p>\nNow, have fun building your own device and inspecting your home’s temperature \ud83d\ude42<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Ok, this time its no retro project, but a rather useful tool to measure your temperatue at home over a longer period of time. I had trouble with my heating devices at home and so I wanted to record and … Continue reading
- On the SD card a data file is always named yymmdd_s.LOG<\/strong> with yymmdd being the current date and s a letter starting from A that is incremented with every new log<\/li>\n<\/ul>\n
- Each line has the following columns:\n
- Now your RTC is set up and you should see incoming measurements like this one<\/li>\n<\/ul>\n
- In both cases have a look at your wiring or your card to fix this…<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
- \n
- Or the SD card was not found:<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
- \n
- Either the sensor was not detected:<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
- \n
- GitHub: ardu.git<\/a><\/li>\n
- an Adafruit Logger Shield<\/a><\/li>\n