I am working on a project and I was hoping for some guidance/ insights from others.
The project uses an arduino due and logs the 12 channels of ADC. The results are then logged to an SD card. An Ethernet shield is being used with the idea of allowing the data log file(s) to be downloaded.
The project does not require the Ethernet link and the logging to be running at the same time. The idea would be like this - hardware boots up with no Ethernet link and the arduino logs to the SD card. When the data is to be downloaded a switch is pressed and the unit rebooted upon boot up the Ethernet code runs and the unit does not log.
I have got the code to get the unit to log fast. This was initially an issue but I overcame the limitations of the SD card write speeds using the library/documentation found here - https://github.com/greiman/SdFat. I am now getting a sampling rate of roughly 500Hz with 12 channels.
My question is how to get the data back off of the SD card over Ethernet. I found the tutorial here - http://www.ladyada.net/learn/arduino/ethfiles.html . I think I can assume that if I get this to work it will not cope with large files and I may end up with large files. 2Gb = roughly 19 hours of logging. It is likely that I will have to log for 12+ hours.
I guess the arduino yun may be able to handle the large files better with FTP but it seems it can't handle fast data transfer over the bridge. Ie can't handle fast transfer between the microcontroller and the Linux side.
I found some examples with FTP on arduino but I don't know if I would just be wasting my time with the file sizes(I have not be able to get any of the examples to work thus far.)
Does anyone have any ideas?