If your data is being logged onto an SD card over a long period of time, then even a 12-16 GB SD card would eventually be low on storage space. Is there a function built into the code by which the data is deleted after a certain period of time? Would the SD card need to be manually changed or have data wiped at regular time intervals? If so, do you know those time intervals?
In short, in order to determine if a 16GB SD card was appropriate for use, we wanted to know how long a 16GB SD card would last, assuming that data was collected continuously. It was concluded that 16GB would last for about 8 years. This is more than enough as the MROC won’t be on and recording data for 8 years straight. In fact, we decided that a 1GB SD card would suffice.
The data logger doesn’t record information when the MROC is powered off; therefore, no information is appended to the SD text file. Also, the logger does have the ability to collect information over extended time periods, but the children won’t be using the MROCs continuously, and it is likely that they will only use the vehicle for a few years as they may grow out of it.
Right now, the logger records information every second. However, we are working to program the device to document only when a case begins and ends. This will eliminate much of the unneeded data within the text file and consume less storage.
“In a set of 10 forwards and reverses measurements, the 16 GB SD card measured only 11 KB in size. A 16 GB SD card will record over a million forwards and reverses. A 1 GB card can record about 10,000 forwards and reverses.” -Dr. Ventura. And yeah as Stacy mentioned, we did some calculations on a sample text file and determined how much data can fit into a 16 GB SD card.