I am trying to figure out a solution to read data off an SD card storing NMEA sentences from a GPS logger attached to an Arduino Pro Micro. The Arduino writes NMEA sentences to a FAT16 text document in a directory on the SD card. The package (SD breakout, Arduino, GPS module, battery) is encased in a small plastic box and the SD card is not accessible to the user.
Ideally, I would like to attach a 3.5mm to USB cable to my project and, over serial, read (through the command prompt or a GUI) the text file(s) off of the SD card to a directory on Windows. Does anyone know of a way I can do this without having to flash a new program onto the Arduino?
I have Googled this furiously but haven't had any luck. Thank you in advance for your help.
EDIT: I'm hoping I can just dump the flash similarly to this command:
avrdude -c usbtiny -p atmega328p -U flash:r:mystery.hex:r Rather I'd want the contents of the SD card, not the flash memory on the microcontroller.