Step 6: H-Bridge... enabled!
So we mentioned the funky green wire before, and here it is!
So we've got two lines coming in from the logic power to j9 and j10. We then have a wire coming h9 down to d13 (pin 1). This wire enables the the left hand side of the chip. There is another wire running from h10 to h20 powering up pin 9.
Why did we do it this way? Why didn't we just send the nice red wire straight through? Because these are not simply power lines. Sometimes (frequently) it is really nice to hook these two pins up to a microcontroller and turn them on and off to conserve power, or pulse them to control speed. In this case we are doing the easiest thing possible and just setting them at full blast all the time, but is good to know that they are a little bit special!