Challenges
Check out more in depth information about a challenge or the electronic components used and examine possible solutions.
Introduction
What is electricity?
Electricity or electric current is the movement of small electrically charged particles in the same direction. These particles are also known as electrons.
What are conductors?
Conductors are materials (commonly metals) which act as a medium where electricity can flow through. It is basically a path to transport electrons from one side of the conductor to the other.
What do electrons do?
While electrons are traveling through a conductor, they are transporting energy from one side of the conductor to the other. This transported energy can be transformed into another form of energy such as light, heat or motion by different electronic components such as a LED or a DC Motor.
What is a power source?
A power source is a source of electrical energy such as a battery or electric generators. You need a power source to start moving the electrons through the conductors. Once the electrons arrive at the electronic components, the transported energy will be absorbed by the electronic component and this component will use the energy to turn it into another form of energy such as light in a LED or motion when the component is a motor. In Short Circuit VR, you can only use batteries of different voltages for now.(1.5V, 3V and 9V)
How to build a circuit?
We’ll start with a very simple circuit: a power source connected to a resistor. Do not connect both terminals of a power source directly with each other (= short circuit). This will cause too much current to flow and thus destroy the power source (battery). To solve this, we will need a resistor with a high enough value to restrict the current. For a 9V battery, the minimum value of a resistor would be 330 ohm. In this circuit you can use a 1000 ohm resistor and a battery of 9V as an example.
Connect the red wire of the battery to one end of the resistor and the black wire to the other end. Using red wires for positive terminals and black wires for negative terminals (GND) is the standard way to connect a power source in electronics. The wires are conductors and so these are the paths for the electrons to flow through. Now the battery is connected to the resistor and you have built a complete (but pretty useless) circuit!
How to test circuits in Short Circuit VR?
If you want to test this in Short Circuit VR, you’ll have to go into ‘power on' mode after building your circuit to cause the electric current to start flowing. We did this so that it’s more clear for the player to see when the current is flowing and when it’s not. So don’t forget to get out of the 'power off' mode and switch to 'power on' mode when testing out your circuits!
Keep in mind that it’s best to connect all the other electronic components first before you connect the power source in a circuit. In Short Circuit VR it’s easy to go from 'power off' to ‘power on’ mode but with real components, the current will start flowing once you have connected the power source, so be careful!
Challenge 1: Breadboard & Closed Circuit
The first challenge is more of an introduction to the breadboard and the idea of a closed circuit.
What is a breadboard?
A breadboard is a small plastic board with a lot of holes (terminals) into which you can push components or wires. Under the surface of the breadboard are metal strips (conductors) that connect groups of holes internally.
The purpose of a breadboard is to make connecting components and wires easier and more organised, without having to solder the components together first. This is why the breadboard is often referred to as a solderless breadboard or prototyping board.
How is the breadboard connected internally?
The breadboard used in Short Circuit VR has two horizontal strips of terminals at the top and at the bottom as well. Each terminal in a horizontal strip is internally connected with the other terminals in that strip. Besides the horizontal strips you’ve got two blocks of 30 vertical strips, each made of 5 terminals. Again each terminal in a strip is connected with all the other terminals in that strip.
How do I use a breadboard?
Usually the battery or another power source is connected to the horizontal strips. You can put other electronic components in the vertical strips and then make connections between the components and power source using jumper wires.
Why do I need to use jumper wires?
Wires are conductors and this is why electrons can be transported from one end of the wire to the other. When the electrons reach the electronic components that are connected to the other end of the wire, energy will be converted into another form of energy such as light from a LED or rotational motion from a DC motor.
What is a closed circuit?
A closed circuit can be considered a closed path connecting both terminals of a power source. For electricity to flow, you’ll need a closed circuit as electric current (conventionally!) flows from the positive terminal to the negative terminal of the power source.
What is the conventional current flow?
As mentioned earlier, electric current flows from the positive terminal to the negative terminal of the power source. This is called the conventional current flow and almost all descriptions of electronic circuits will be using this direction of flow. However, keep in mind that in reality, electrons are flowing physically from the negative terminal to the positive terminal and this is known as the electron flow.
What is an open circuit?
You have an open circuit when there’s an opening anywhere in your path, interrupting the current from flowing between the terminals of the power source. This way electrons are not able to reach other components or the power source and as a result, the electric current stops flowing.
What is a short circuit and how to avoid it?
While we need a closed circuit, connecting both terminals of a power source directly will cause too much current to flow and may end up breaking or even burning something. This is called a short circuit and must be avoided at all times. To restrict the current from flowing this much, we can use a resistor.
What is a resistor?
The resistor is a passive electronic component that can be used to restrict the flow of electric current. It can be found in a lot of electronic circuits. The resistance is measured in Ohm(Ω).
Resistors come in many different values. The higher the value, the more it will restrict the current. Not all resistor values exist due to production and storage constraints.
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Solution Challenge 1
To successfully finish the challenge, you can spawn any resistor out of the components menu and add it on the breadboard. Make sure both terminals of the resistor are not placed in the same strip. You can spawn two wires from the menu to connect each strip to the horizontal strips connected to the battery. It is the standard way in electronics to use a red wire for the positive side of the power source and black for the negative side to make it more clear.
Challenge 2: LED
Challenge two asks the player to connect a LED correctly.
What is a LED?
LED is short for Light Emitting Diode. As the name suggests a LED is a diode. In general a diode is an electronic component that allows current to flow in only one direction. The two terminals of a diode are called anode and cathode. Current only flows from the positive side (anode) to the negative side (cathode). So definitely keep the polarity of this component in mind or else no current can pass through the LED and will therefore not be able to light up at all.
How do I use a LED?
The cathode has to be connected to the negative side of a circuit and the anode to the positive side to have it forward biased. You can recognize the anode pin on a LED by the sligthly longer length than the cathode pin.
Besides polarity being an important issue, it is equally important to add a resistor to restrict the current. The resistor we need depends on what voltage the power source has that we will be using. A diode needs a minimum specific voltage (voltage drop) across it before it will allow current to pass through it.
A regular LED, as in the application has a voltage drop of 1.8V and a maximum current of 20mA. If you don’t add a resistor to the circuit, the LED will break because there is too much current flowing through it.
What is ampere(A)?
Ampere(A) is the basic unit to describe the rate of current flowing through a conductor.
What is current (I)?
Current(I) is the flow of electric current. The unit to measure current is ampere(A).
What is voltage(V)?
Voltage(V) is the force that pushes electrons through a conductor. The unit to measure voltage is called volts(V). The higher the voltage, the stronger the electric current that flows through a conductor.
Ohm's Law
Ohm’s law describes the relationship between the voltage, current and resistance.
This formula is extremely important in electronics and you’ll need it in a lot of situations.
Ohm’s Law: voltage = current x resistance (V = I x R)
You can get other versions of the formula by changing the places of the terms:
I = V / R → to calculate the current
R = V / I → to calculate the resistance
The unit of V is volts, I is measured in amps and R in ohms:
Volts = Amps x Ohms
V = A x Ω
Be careful not to mix the units of measurement. Make sure you convert any kilos and millis to the standard unit!
(e.g. 20mA = 0.02A)
How to calculate the value of the resistor?
To calculate the value of the resistor we will use in the circuit, we need to use Ohm’s law. (V / I = R)
But since a LED is a diode, which is an active component, we first need to subtract the voltage from the power source with the voltage drop over the LED (1.8V). If we use a 9V battery for example, we can calculate it as following:
(9V - 1.8V) = 7.2V.
Use the result and fill it in as the voltage in Ohm’s law. (7.2V / I = R)
We know that a regular LED has a maximum current of 20mA (=0.02A). So to get maximum brightness from the LED, we’ll fill in 0.02A. (7.2V / 0.02A) = 360Ω. This means our resistor has to have at least a resistance of 360 Ohm. It is always safer to take a resistor with a little higher value so the current will be a bit less. 390 Ohm is the first resistor closest to the value so we could use that.
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Solution Challenge 2
Spawn a red LED and a resistor that has a minimum resistance of 360Ω. (e.g. 390Ω) Place the LED in the breadboard while knowing which pin is the anode pin (longest pin). Connect the resistor in series with the LED. To do this, connect the resistor either with the anode side or cathode side of the LED. Then use jumper wires to connect the anode side to the positive side of the battery and the cathode to the negative side.
Challenge 3: Slide Switch
The third challenge is connecting a slide switch with a LED.
What is a slide switch?
A slide switch is a component that is used to toggle a connection. It can be used to switch between two conductive paths where the current will only flow through the chosen path, or in some cases to prevent any current from flowing at all (when one of the connections of the slide switch isn’t connected to anything).
How do I use a slide switch?
A slide switch has 3 terminals in total. The position of the handle determines which one of the two outer terminals will be connected to the center terminal. By sliding the switch, you disconnect the center terminal from the previous connected terminal and connect it with the other outer terminal where the handle is positioned.
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Solution Challenge 3
To complete this challenge, you will need to place a LED in the breadboard, connect a resistor (min. 360Ω when using a 9V battery) to the anode side of the LED and connect an outer terminal of the slide switch to the cathode side. Close the circuit by connecting the other end of the resistor to the positive terminal of the battery and by connecting the center terminal of the slide switch to the negative terminal.
Challenge 4: Pushbutton
The fourth challenge is quite similar to the third. Instead of using a slide switch to toggle the LED, you must use a pushbutton.
What is a pushbutton?
When pressing on a pushbutton, it will connect all the terminals together internally. So by placing a pushbutton in a circuit without pressing on it, it will keep the circuit open and thus prevent any current from flowing through the terminals of the pushbutton. Pressing on it will close the circuit until you release it again.
How do I use a pushbutton?
A pushbutton has 4 terminals with each terminal already connected internally with it’s opposing terminal. Therefore you often only need to use two of the terminals in your circuit.
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Solution Challenge 4
Put the LED in the breadboard with the resistor on the anode side and the pushbutton on the cathode side. Close the circuit by connecting the other end of the resistor with the positive terminal of the battery and by connecting the terminal of the pushbutton, that is not connected to the circuit in release state, to the negative terminal of the battery. Make sure you’re not using two terminals of the pushbutton that are already connected internally. So when you’re not pressing the pushbutton in this challenge, it will cause the circuit to be open, preventing the current from flowing and likewise the LED from lighting up.
Challenge 5: Potentiometer
Challenge 5 is an introduction to the potentiometer.
What is a potentiometer?
A potentiometer is a component that allows you to control the resistance in the circuit. This component is basically two resistors of which you can change the value by turning the knob on the potentiometer. When you turn the knob in one direction, one resistor will reduce in resistance while the other increases in resistance.
How do I use a potentiometer?
The potentiometer has three terminals. The outer terminals are each connected to an end of one of the two (internal) resistors and the center terminal is connected at the middle where both resistors are connected as well. Just like with the slide switch, it is not necessary to use all 3 terminals as you often only need to use two: an outer pin and the center pin. Connecting this in a circuit and by turning the knob, the current will increase/decrease depending on which direction you turn.
For example when you use a potentiometer of 5kΩ, the total resistance between the two outer terminals is 5kΩ. When you turn the knob so that the resistance between terminal one and two is 1kΩ, then that means the resistance between terminal two and three is 4kΩ.
Keep in mind that if you turn the knob so that one side of the potentiometer will have a small resistance or none at all, other components connected to that side can break because of the current being too high. So it’s best in general to add a regular resistor as well when using a potentiometer to prevent destroying components. This challenge does not include a separate resistor so that it’s easier for you to see what happens when you increase/decrease the resistance of the potentiometer.
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Solution Challenge 5
Put the potentiometer in the breadboard and connect the LED to one of the outer terminals of the potentiometer. Then make sure the anode side of the LED is connected to the positive side of the battery and the center terminal of the potentiometer connected to the negative side of the battery to close the circuit. During 'power on' mode you can change the value of the potentiometer to see how it affects the LED brightness.
Challenge 6: 7 Segment Display
Challenge 6 brings in a new component: the 7 segment display. A name which may be a little confusing as it actually has 8 displays if you include the decimal point at the bottom right corner.
What is a 7 segment display?
The 7 segment display is a component made out of several LEDs internally. The 7 segment display used specifically in Short Circuit VR is a common cathode display, which means that each cathode of the 8 LEDs is connected internally to the center pins at the top and bottom of the display. So all the other pins are the anodes of each LED. Look at the diagram below to know which anode belongs to which segment exactly.
How do I use a 7 segment display?
Connecting either one of the center pins (top or bottom) to the negative terminal of the power source is sufficient as they’re both internally connected anyway. Because the segments are LEDs, each one still needs to be connected to a resistor to prevent the LED from getting too much current through it.
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Solution Challenge 6
To finish this challenge successfully, you must connect one of the common cathode pins of the display to the negative terminal of the battery. Then you can pick any of the anode terminals and connect it, not forgetting to use a resistor (at least 360Ω with a 9V battery), to the positive side of the battery.
Challenge 7: 7 Segment Display (4)
Challenge 7 is easy if you’ve understood challenge 6. Instead of connecting only one anode, you need to connect several more (4 to be exact) to make the 4 shape on the 7 segment display. Remember that each connected anode needs to be in series with a resistor.
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Solution Challenge 7
Push the 7 segment display into the breadboard and connect one of the cathode pins to the negative side of the battery. Spawn 4 resistors (min. 360Ω with a 9V battery) and connect each resistor to one of the following segments: f, g, b and c. Then connect the other end of the resistors to the positive side of the battery.
Challenge 8: Buzzer
Challenge 8 asks the player to connect a buzzer.
What is a buzzer?
A buzzer is an electronic component that makes a buzzing noise at a specific frequency. There are several buzzers in the components menu to give you the option to pick a buzzer with a certain frequency of your liking.
How do I use a buzzer?
A buzzer does have a polarity, much like a diode. Connecting it wrongly in the circuit can destroy a buzzer. Luckily you are allowed to make mistakes in Short Circuit VR, but this challenge isn’t too hard as the colors of the wires of the buzzer indicate quite clearly which end needs to be connected to which terminal of the power source.
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Solution Challenge 8
Spawn one of the buzzers from the components menu and connect the red wire to the positive terminal of the battery and the black to the negative terminal.
Challenge 9: DC Motor
In this challenge, we get to work with a DC motor and a potentiometer. The potentiometer has to be connected in a similar way as in Challenge 5, but instead of dimming a LED, we will be controlling the speed of the motor.
Remember that a regular potentiometer is not the best component to control the speed of a DC motor. For this you should normally use power potentiometers or some kind of transistor, but those components are not yet included in Short Circuit VR at the moment.
What is a DC motor?
A DC motor is a component where the shaft rotates at a speed which depends on how much current is flowing through it. Once the shaft is rotating, you can hover with your controller over it to see the rotations per minute. A DC motor can be connected both ways but depending on the polarity the motor will turn one way or the other.
How do I use a DC motor?
A DC motor has 2 terminals but it does not matter which side of the power source is connected to which terminal. The motor can be connected both ways but depending on the polarity, the motor will turn one way or the other. When you’ve connected the motor, you can attach an object to the tip(shaft) of the motor to watch it spin.
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Solution Challenge 9
To get started, you will have to spawn wires and then attach one end of each wire to a terminal of the motor, because the terminals do not snap into the breadboard directly. Then place the potentiometer in the breadboard and use one of the wires of the motor to connect to the center pin of the potentiometer. Close the circuit by connecting the other wire of the motor to the negative side of the battery and one of the outer pins of the potentiometer to the positive side.
Once you’ve connected everything as shown in the diagram, you’ll be able to turn the potentiometer and slow down or speed up the motor. You can attach an object to the tip(shaft) of the motor to watch it turn more clearly.
