LCD and SD card fail to co-exist | Arduino Compatible Compiler for LabVIEW Discussions | Forum

You likely have a memory leak.  Take a look at the Important Considerations in the user manual.  You have to take care on these platforms as you can easily use up all memory if not coded properly.

In you first VI the problem is that you are creating/initializing the LCD on each iteration.  This is creating a new object for every iteration which will quickly eat up your memory.  You need to pull initialization functions outside the while loop.

In your second VI you are never closing the file.  It is outside the loop which will never terminate, and the close file will never execute.  You should be closing the file to purge the data to disk.  Otherwise it will keep the data in memory and eventually run out.  Take a look at the included "SD Card - Simple Datalogger.vi" example.  This one should run without the issues you are seeing.

It still appears your file write is outside the loop, as I mentioned is a problem.  That is probably where your memory leak is.

That VI has the same problem I just mentioned.  Your SD File Close will never run, therefore the data will sit in RAM until you run out.  You need to flush the data to the SD card using the File Close INSIDE the loop.

It looks like in the case you identified as not working, you are creating an array of string to display on the LCD, but in the loop you are wiring those strings to the same lines on the display with a 300ms update rate.  So not sure what you expect to see but if you don't clear the line first you will see characters from the last string, and 300ms is somewhat fast.  Can you explain what you are seeing?

I would try getting rid of all your unused code, case selectors and case statements.  Even though you are disabling them with boolean inputs, they are taking up code space and creating a lot of extra memory copies.  And you have an array control with ~100 bytes sitting on the front panel.  Every time your array wires hit case structure boundaries, selectors, etc. you create a memory copy of that complete array.  It could be that you are running out of memory.  Try creating a copy of the VI with all the unnecessary code removed, or use disable structures instead to remove the code. 

The SD card library does take up a lot of memory, but that's a function of the core Arduino libraries.  One option is to go to a bigger Arduino platform with more memory.  You can also take a look at the Saving Read-Only Data to Program Memory.vi example.  This shows how you can store large arrays of read-only data to Program Memory instead of RAM.  That might benefit you here.  You can use the check unused RAM function but that doesn't tell you about fragmentation.  You could have 100 bytes free, for example, but not in contiguous space, so if an array is copied that requires more bytes than this, the memory allocation will fail.