Project Curacao used two computers. One (a Raspberry Pi) to do all the brainy functions like graphs, WiFi and cameras. It used a second computer (an Arduino Mega) to run the weather instruments and make samples. The deal was that the Arduino was always on so when the Raspberry Pi was off, it would store the values to an FRAM. When the Raspberry Pi woke up, it would gather all the samples and put them into it's MySQL database.
Turns out with an Arduino, you don't need the FRAM, you can use the EEPROM, but the FRAM was a lot cooler and had more storage.