After getting some hints from MarkT in Teensy forum, I am able to come out with the solution!!
Sharing these findings here, incase anyone needs a reference:
Part 1: Non-blocking Serial parsing (focus more on example 5)
Serial Input Basics - updated
Continued from previous Post Receiving numbers rather than text So far the examples have assumed you want to receive text. But perhaps you want to send a number or maybe a mix of text and numbers. Example 4 - Receiving a single number from the Serial Monitor The simplest case is where you...
Part 2: Controlling stepper motor through serial monitor to a fix position
With some modification on Part 2 coding with the reference of Part 1, the response is significantly increased and stepper motor can rotate at a desired speed