Here's what my code looks like to write to the serial port:
So we cannot see the important bits, i.e. the code that could be causing the problems.
I have 5 sensors hooked up to my Arduino nano:
- 1 barometer
- 2 accelerometers
- 1 gyroscope
- 1 GPS receiver
Given that setup, and that you also want to add an SD card and your using Strings (eek! run for the hills) , I would imagine the chances of the program fitting in a Nano and\or being stable are fairly close to zero.