CHAPTER 26
■ Chapter 26: Smoother, Smaller, Cheaper
Sandwich uses a “preprogrammed” chip and large through-hole parts so that the circuitry is easy to learn
and build. This chapter explores the benefits that can be achieved without such constraints.
The first design modification takes the wiggle out of the robot—sacrificing goofiness for speed. After
that, a much more radical change uses modern tiny parts around a programmable brain. Guess how that
impacts the price!Playing with Sensor Circuitry
A reader and nearby robot builder, Terry Jackson, increased the line-following efficiency of Sandwich with
some ingenious revisions to the sensor portion of the schematic. Figure 26-1 presents the original and
revised circuits. Notice that the parts are the same; they are just wired differently. The only exception is that
R1 has been duplicated to become R1A and R1B.Figure 26-1. Revision to the Sandwich light-sensor circuitry for smoother line following