CHAPTER 27 ■ ENCORE
A plastic piece, called a “shorting block” (see Figure 27-10), containing a thin strip of metal is placed
over a pair of pins on the male header on the circuit board. Thus, the metal strip connects the pins as a
switch would.
Figure 27-11. Tilt switch consisting of a metal ball surrounded by metal pins within a plastic cube
Figure 27-10. Male header and shorting blocks
Jumpers and shorting blocks are less expensive than DIP switches, take up less space, can handle a bit
more current, and can be cut down to a single pair of pins if desired. In most cases, I prefer DIP switches for
configuration, since they don’t have parts that can come loose and become lost. However, shorting blocks
provide multimeter access to the male header’s metal pins, so current flow can be tested.
Tilt Sensor
You can imagine the futility of an upside-down robot spinning its wheels. The first step toward a robot
righting itself would be to know it has tipped over (sort of a 12-step program for robots).
Figure 27-11 is a part that I’ve always been meaning to try out. A metal ball rolls around a bunch of
metal pins. Whenever the ball touches two or more pins, they’re connected together electrically. That way, a
circuit could detect if the robot was upside down or tipping in some direction by checking to see which pins
were “switched” together.