Here she is, the integrated prototype. Note the cowling is fastened on the back and that the breadboard has just the ATMega328, not the whole entire Arduino board.

An overhead view showing the arrangement of the servos, wheels, breadboard, and photoresistor cowling.

Side view. Why did I use cladding rather than the horn that is typically provided in the servo package? Don’t remember, in a hurry I guess and didn’t want to do the extra drilling. I would do it differently now.

From the other side. The loose jumper wire is for turning the robot on and off in lieu of a switch. Switches are surprisingly expensive.

Frontal view. You wouldn’t want to meet this in a dark alley, if you were a mouse!

Photoresistor (aka LDR) inside the cardboard box cowling, which shields the readings from ambient light (sort of).

Close up of the cowling interior. Note the high-tech thumb tacks used to attach the cowling to the chassis. Elmer’s Glue did not work, which is strange considering that we’re talking about joining cardboard and wood.

Underbelly view, showing the plastic caster. That thing is nice but expensive and unfortunately I’ll have to leave it out in production models. I’d like to have brackets instead of rubber bands to hold down the servos, but they’ve been surprisingly effective.

(Click on image to enlarge.)

A close-up of the breadboard with the schematic for reference. As is commonplace in the electronics world, the position of the components in reality doesn’t always agree with the placement on the schematic, but the wiring is correct (I think).

(Note the sticker on the ATMega328 with the Arduino pinouts identified. This chip was purchased stand-alone, in other words it did not come mounted on an Arduino but did have the Arduino boatloader pre-installed, and the very useful sticker came with it.)

And now, in case you want to do a comparison between myth and reality, you can check out my preliminary sketchup designs here.