Arduino: Sensor sending two different data at the same time

Questions
4

The missing element is that you need two levels of looping, but you’re trying to do it with only one.

The algorithm should read:

  1. Collect characters into an array as long as they are decimal digits – this may comprise multiple digits, so it must be an inner loop, which is most easily expressed by while.

    while {
    ascii = ~port.read.asAscii;
    ascii.isDecDigit
} {
    charArray = charArray.add(ascii);
};

  2. After this, ascii will be a non-digit. Use this character to decide which value is set.

    value = charArray.collect(_.digit).convertDigits };
switch(ascii)
{ $a } { ~val_01 = value }
{ $; } { ~val_02 = value }

And all of that runs in an outer loop.

This way, you need only one charArray. Also, charArray is properly local.

(
~charArray_01 = [ ];
~charArray_02 = [ ];
~getValues = Routine.new({
	var ascii, charArray, value;
	loop {
		while {
			ascii = ~port.read.asAscii;
			ascii.notNil and: { ascii.isDecDigit }
		} {
			charArray = charArray.add(ascii);
		};
		value = charArray.collect(_.digit).convertDigits;
		charArray = nil;  // EDIT: Need to clear the list!
		switch(ascii)
		{ $a } { ~val_01 = value }
		// (or maybe 'b' would make more sense here?)
		{ $; } { ~val_02 = value };
	};
}).play;
)

hjh