I'd like to extract data collected by a battery powered arduino for example once a day without stopping it and not using SD card.
It's posible, when I want to extract the collected data, to connect a laptop through the USB and then get data because Arduino is, at regulat time intervals, calling 'Serial.println(...)'?
This is a bit crude, but I think you could use an FTDI cable (which is a USB to UART converter) to have a program in your laptop talk to the Arduino using its UART (serial) interface.
To do it, you could plug the USB side of a FTDI serial cable to your laptop. The other end of the cable has a plug with 6 pins, 2 of which are the TX and RX serial signals. You could plug those two signals to pins D0 and D1 (RX & TX) of your Arduino using male-to-male jumpers.
In terms of software, you could code the Arduino sketch to listen on the serial port for a command from your laptop. When the command arrives, it would output the stored data (could be comma separated values with CR+LF as end of line). Your laptop would then listen for the answer and retrieve the data.
Yes, you can do it. Depends how much data to have enough storage space. You also need consider potential memory endurance. E.g. external I2C ferromagnetic memory is good option. Of course it's not on Arduino board, you implement extension.
