Notice that we connect the switch to the red cables and not the black. That is standard practice aimed at minimizing the points through which power can accidentally be connected to other electrical components. Stopping the power near its source is the best way to do it.
The motor’s contacts are connected by a wire that is wrapped in a special way. When electricity flows through the wire, it creates a magnetic field that makes the shaft spin. The direction the shaft spins depends on which way the electricity flows. If you switch the wires, the shaft will just spin the other way, and nothing bad will happen. The plus (+) and minus (–) marks on the motor only show which way to connect it if you want the shaft to spin in a certain direction.
You can notice that the two positive terminals are placed in the middle. That is a common practice that has a few functionalities, like shortening the paths on the PCB, but the main purpose is to lower the chance that the power cables connected directly to the battery are more difficult to touch accidentally.
To demonstrate that it does not matter where in the circuit we place the switch, we placed it at the negative battery terminal. However, in practice, it is always better to put it near the positive terminal as it lowers the area that can damage your electronics if accidentally touched by other power sources or grounding.
Time to make the final connection and complete the prototype.
If you’ve connected everything correctly, you can now turn on the motor and control its speed using the potentiometer.
The potentiometer is the small knob on the motor speed controller that you can rotate.
time to plan where everything on the PCB will go. You can rearrange the components as you wish, as long as the wire connections are done correctly after that.
The dip switch is mounted by using the holes that are already placed on the PCB board. Meaning that we don't need to drill any holes for it.
There is a way of mounting the drill bits faster and more reliably than what is shown in this video; however, it requires a steady hand and starting the drill while the drill bit is not yet mounted. We decided that it may pose danger for people not yet savvy with the drill, and that it is best to show how it was intended to be mounted. We strongly advise not using faster methods before you are very comfortable handling this tool.