In this lab, you’re going to learn more about circuits. First, you’re going to use a relay — an electrical switch — that allows you to turn on and off parts of your circuit. Then, you’re going to practice calculating resistance. Finally, you’re going to diagram your circuit.
1. Complete Circuit 11, Relays, in your Vilros Ultimate Starter Guide. If your relay doesn’t work, check all your wires. Trace the circuitry and think about how the current is flowing. Look at the axon drawing to see how the relay should be oriented. If that still doesn’t work, flip the orientation of the diode (for me, I needed the dark side of the diode on the right).
2. Make your circuit a little more exciting. On one side of the switch, run 2 LEDs in series. One the other side, run 2 LEDs in parallel. When each side is activated, write to your serial monitor: “Parallel On” or “Series On.”
3. What resistors do you need for your circuit, according to Ohm’s Law? You’ll need to calculate this separately for each side of the switch. Show me your math. Make sure your circuit uses the most appropriate resistors. (4 points)
4. Take a short video of your circuit in action. Be sure to show the wiring well enough that I can actually see one side is wired in series and one in parallel. Also, be sure to show the serial monitor. In your video, feel free to talk and point to things. (8 points)
5. Draw a circuit diagram for your new circuit. Label everything, just as it’s done in the circuit diagram in your starter guide. (6 points)
Note that there are several different ways to go about drawing a circuit. This software, Fritzing, seems to be popular in the Arduino community. There are many other options available — just search around. You can even use a pen and paper (and a scanner). Whatever you use, make sure your circuit is clear.
6. Read about the why your resistors are colored as they are.
7. Read about how to destroy an Arduino. This link is a little strange because it’s an advertisement for an Arduino spin-off called a “Ruggeduino” that can supposedly withstand all the things you can do to kill your Arduino. But, it’s also a clear list. (If you think your circuit diagram was complicated, check out the ones they show on this page.)
8. If you’d like to read more about the basics, check out this primer on voltage, current and resistance at Sparkfun. It also includes links to tutorials on electricity and circuitry.
9. Or, check out this one on Adafruit. Start here and then keep clicking through to read “Revisiting Resistors,” “Revisiting Volts,” and “What to Adjust?”.
10. As always, post your assignment on bSpace.