Is there a way to save these logs? Is it possible with just arduino, or I would need another peripheral?
You would need a RTC (realtime clokc) and SD card for data logging shield plug on top of the Arduino..
You can retrieve the data from the SD card and plot the graph somewhere else..
I wrote a beginner blog by beginners and I've an entries talking about different sensors ( too many of them ... ) ... just click on the WWW below..