"How should I do trouble shooting at this point."

You need to use an oscilloscope (or logic analyser) to see what your project is actually doing, and see where that deviates from the specs.

You could also try looking at what a real mouse does, and spotting the difference.

"Have anyone ever written code for x51 microcontroller"

As its been around for 20 years or so, I suppose the odd one or two must've tried something at one time or another... :-)


Why not try that 'Search' button??