Please see this Parallax forum post for a good diagram of how to wire the HB-25’s, motors and encoders:
It is worth looking at the ActivityBot setup too: http://learn.parallax.com/activitybot/electrical-connections which explains the server connections, which are also used for the motor controllers, and the use of pull-up resistors.
Also this thread has some good information on the the “ActivityBot”code that I use to control the motors:
TODO: Write up a full wiring description with diagrams of every component . . .
The rest is just a collection of high resolution photos of the robot’s wiring. I hope these may help others imagine how to wire their ArloBot!
Click on each image for a full resolution version. Download them as you see fit and if you build a wiring diagram of your own please let me link to it! Or I can host it of course if you want.