[Mark McLeod]

In engineering, it's unusual to throw a lot of new things together, turn it on and expect it all to work together.

Normally, we'd test each sub-system independently, and work out the bugs in each, before trying them together.

Errors in one sub-system can mask errors in another sub-system. Two wrongs can make an inadvertent right, then later on when an unnoticed error gets corrected, suddenly the software that was working so perfectly stops working.

Then, when you begin to put sub-systems together, you want to develop a step-by-step test plan to verify that each piece is working properly. Inspecting the PWM orders coming from the software is one of those tests.