I couldn't get the sensor readings on my phone, can you please help!

check2.aia (586.8 KB)

P.S. These blocks can be dragged directly into your Blocks Editor workspace.

See A way to group projects by theme - #10 by ABG
for a demo.

Please post your .ino sketch here so we can see if you are using printLN() properly.

Your Delimiter handling needed correction, according to this standard advice:

Please see the Delimiter article in FAQ

Be sure to use println() at the end of each message to send from the sending device, to signal end of message. Do not rely on timing for this, which is unreliable.

In the AI2 Designer, set the Delimiter attribute of the BlueTooth Client component to 10 to recognize the End of Line character.
BlueToothClient1_Properties
Also, return data is not immediately available after sending a request,
you have to start a Clock Timer repeating and watch for its arrival in the Clock Timer event. The repeat rate of the Clock Timer should be faster than the transmission rate in the sending device, to not flood the AI2 buffers.

In your Clock Timer, you should check

  Is the BlueTooth Client still Connected?
  Is Bytes Available > 0?
     IF Bytes Available > 0 THEN
       set message var  to BT.ReceiveText(-1) 

This takes advantage of a special case in the ReceiveText block:

ReceiveText(numberOfBytes)
Receive text from the connected Bluetooth device. If numberOfBytes is less than 0, read until a delimiter byte value is received.

If you are sending multiple data values per message separated by | or comma, have your message split into a local or global variable for inspection before trying to select list items from it. Test if (length of list(split list result) >= expected list length) before doing any select list item operations, to avoid taking a long walk on a short pier. This bulletproofing is necessary in case your sending device sneaks in some commentary messages with the data values.

Also, your color range tests are inconsistent.
I tried to fix one of them, but I don't know what your original requirements were.
Setting range colors is typically done by laddering your tests in strictly ascending or descending boundary tests in an if/elseif ladder, one boundary at a time.