IPC Class 2 Reading and Labs

Lab 1: Components

Some of the most helpful things I found in this lab:

Why microcontrollers are powerful: because they allow you to separate your object (or circuit) from its behavior. This allows you to leave your circuit the same, but change its behavior with a program.

Why the number 1023 is shown in the serial monitor: Your arduino’s microprocessor uses its Analog to Digital Converter (ADC) to take a changing voltage of 0 – 5 volts and convert it to a digital number range of 0 – 1023 (there is some mapping/translating math to arrive at this digital conversion.)

Lab 2: Setting up a breadboard

Question: My DC power supply is still on order so I haven’t learned how to solder to make the DC power jack connection.  However, I did these powered by my laptop.

Question: After going through the examples, I’m still wondering why the resistor and conductor row have the ability to bypass the LED, causing it to not light.





Lab 3: Electronics and using a Multimeter

Here is my work, notated at the top of each image.

Pictured here are 5 volts measured across power and ground in my circuit with my multimeter, powered by my arduino and laptop.



Below you can see two LEDs in series turned on by pressing a button, which connects the switch inside to allow voltage (or current?) to pass through to the 220k ohm resistor and LEDs.  While in series, the LEDs divide voltage yet the current is the same across them.

Question: I’m confused about when I should be saying voltage or current is passing through a circuit.

Note: Adding a third LED leads to none of the LEDs lighting up. This is because each LED uses up about 2 volts. Therefore, the 5 volts sent by my arduino & laptop is not enough to power 6 volts worth of LEDs (three 2 volt LEDs). Instead, about 6 volts would be necessary.

giphy two LEDs

Here you can the circuit uses up nearly all of the voltage in the circuit. My math compares the total voltage in the circuit with the combined voltages across each component.



Here, three LEDs are lighting up because they are in parallel. This parallel arrangement gives equal voltage to each LED, but divides the current among them.

giphy 3 LEDs to measure voltage.gif


Below I am measuring the amperage or current across a single component in my series. To do so, I removed one side of one component. In this case I removed the anode leg of one of the LEDs and completed the circuit with my multimeter.

It took several tries to do this while I figured out whether to have my multimeter set to which Amperage hole (200 milliAmps instead of 20 Amps) or which Amperage dial setting (20 milliAmps instead of 200 or 2milliAmps).

Also it was hard to press the button while I held the multimeter!

giphy of three LEDs connected by meter

I didn’t complete the potentiometer circuit because I haven’t learned to solder yet (soon!). But I did something similar during office hours and understand the concept and circuit.

Lab 4: Switches

Switches in parallel.  As long as you press the first one, you can press either of the second two buttons. This is because they are all connected by wires in such a way that both LEDs get voltage/current with whichever combination.

Can press either last two buttons to light lED


Switches in series. In this case, you need all three pressed to light up all three LEDs. This is because the third button is not directly connected to the first button.

Need all 3 pressed for LED



Question: I can see how the schematics are different for each circuit, in that parallel components are drawn going down, and series components are drawn across. Is this the way parallel and series are always drawn?

Connecting two of the last buttons to allow a different combination to be able to turn on both LEDs.

Question: Why is that the current/voltage passes through the third button to the second LED, even if I haven’t pressed it? Is it because current can pass through the bottom of a button even if it’s not pressed?

Can press either last two buttons to light lED



Create a dual pole switch, so that two separate circuits are turned on with the same mechanism. (I thought this had to be a special kind of switch, but turns out a momentary switch or button is fine.)

Question: I know the IC1 in the schematics are referring to the voltage regulator in the schematics, but why is it called IC1?

giphy LED and moto.gif