The Raspberry Pi, running the Raspbian OS, booted into a standard terminal mode. During the boot process, an init script would start the data collection process from the Arduino and the Dylos serial ports. This data was then stored in an incrementing file name, to prevent overwriting files, over each on-off power cycle. In addition, a one minute file-write timer was built into the logging software to ensure that data was written on a continuous basis, since the sensor package was turned off by having its power removed.
The Raspberry Pi, Arduino Uno, and all power hardware is stored in a Rubbermaid container that is placed inside an inexpensive backpack. The Dylos is attached to the outside of the backpack to be exposed to the ambient air.