How to use hc-05 with pic32
BLT_BUF should be declared volatile for a start. Secondly, your delay should be before where you check for "OK". You have those for loops that do no meaningful delay (in all likeliness they will be optimised out by the compiler), then you expect the result to be there straight away when in all likeliness it might not be.

It is always helpful to be able to print out the contents of a buffer (BLT_BUF) so get some sort of usb converter for your pc or examine the contents via a debugger. You want to know if it receives anything at all, first and foremost. Check this before you loop back and erase the buffer.