CHAPTER 13 ■ SOLDERLESS BREADBOARD SETUP
This is why distribution buses are so valuable. You can add individual modules and mini circuits
anywhere on the board and it will be as if they all were connected directly to the battery. Of course, the
5-position groups aren’t connected to the buses, so you can deliver the desired voltage and current to them
based on your choice of resistor or other part.
With the black test probe connected to negative power, insert a wire connected to the red test probe
into the 5-position group that contains the LED anode (see Figure 13-12). You should get a reading of 1.8 V
(or thereabouts), just as you did when the power indicator circuit was put together with alligator-clip jumper
leads.
Trimming Leads
After testing a part or circuit on a breadboard, you may want to cut down the part’s leads. Short, flush parts
stay out of your way and there isn’t the risk of their leads accidentally brushing against other wires.
The LED and resistor of the breadboard power indicator are good candidates for trimming down.
Chances are you’ll leave those parts in the breadboard for almost all experiments.
Demystifying the Robot’s Power Switch
The power switches on most robots are no different than the power switch you installed on your breadboard.
Robot power switches may look more striking, handle more voltage, or make multiple connections at the
same time. However, robot power switches still employ the same technique of making and breaking a
connection to the positive terminal of the power source.
In fact, nearly all robots deliver power to their circuits and modules using a power bus, just like a
solderless breadboard. Figure 13-13 is a photograph of the underside of Sandwich’s circuit board. It has
an array of holes, just like a solderless breadboard. Toward the middle, there are two long lines that all the
various circuits are tapping into. Those are the positive and negative buses.
Figure 13-12. Multimeter probes with jumpers testing voltage at the LED’s anode