I am trying to send "AT+ACK" but returns me "AT+AV" on Pro Mini

Attached is my code:

this issue happens at the following section inside the third while loop when I am trying to sending AT+ACK mySerial.print(myString) returns me "AT+AV" or other random string not "AT+ACK",which is what I expect: anthing before that point works perfectly I have no idea what's going on here:

wonder if anyone can give me some advice.

I have used 69% of the SRAM not sure if that's the case

MainProMini.h (7.14 KB)

Post complete code
2)
Read How to use this forum - please read, specifically point 7. If it's too big, attach it.
3)
The use of String (capital S) is not advisable in the best of times in Arduinos; it absolutely should be avoided if you start running low on memory (and 30% free is getting there).

And you only have an include file ? I'm on a cell phone so can't view, but it sounds strange if that is the case.

Hi sterretje,

I have attached the main script. Now I open a new script and only put that case DAQ0 in it, now I encountered the same issue please also see the screenshot I attached. This time only 28% of SRAM has been used I feel so strange. It still gets stuck at the same position.

But the format I am sending over the serial port is a string e.g. "{1,2,3,4,5,6,7}\n" so I did not choose to use the

Now please include a complete sketch and supporting files that can be compiled.

3 nested while loops is usually not the way to go; I think you could benefit from reading up on state machines.