This blog post on basic electronic components contains short excerpts from the first six lessons of Level A of our Intro to Robotics program. Level A covers building circuits, using a Raspberry Pi, and writing common code commands in Python. It contains 18 lessons including 70+ videos and 45 projects and activities. Sample lessons and a full scope and sequence for Level A can be found here.
Level A of the Intro to Robotics program starts at the very beginning by teaching you to build breadboard circuits using common electronic components. Later in Level A you learn to use a Raspberry Pi (single-board computer well suited to electronics and robotics projects) and then you learn to write code in Python. By the end of Level A, you will be controlling the electronic circuits you build with Python code you wrote yourself.
This article contains excerpts from the first six Level A lessons and provides a brief introduction to circuits, breadboards, resistors, light emitting diodes (LED), jumper wires, switches, and red-blue-green light emitting diode (RGB LED).
What is a Circuit?
A battery (or wall outlet, etc.) contains what is called potential energy. This energy, in the form of electricity, if given a path, could move out of the battery or outlet and power a light or other electrical object. For the electricity to flow (specifically the positive charge), you would start by attaching a wire which would transfer (or conduct) the current. But just attaching a wire won’t cause the current to flow, there needs to be a negative charge on the other end attracting the positive charge. This is why every source of electricity (such as a battery) has two sides, the positive side produces the charge, and the negative side draws the charge in.
A basic circuit consists of a wire connected to the positive charge of the battery which allows the electricity to flow through several components (e.g. resistor, LED, switch, etc.), all of which utilize some of the current, and then flow to the battery’s negative charge. With a complete path from the positive charge to the negative charge, the current flows through (and powers) the components.
Breadboard
The Intro to Robotics course teaches you to work with a breadboard to build electronic circuits. Officially called a solderless breadboard, it will allow you to build circuits that can be assembled, changed, and disassembled quickly. The alternative would be to solder components together, but this would be time consuming and difficult.
A breadboard has no internal power source, so it must be connected to a battery in order to power circuits. A breadboard contains holes spaced 0.1 inches apart. Underneath the plastic, metal conductors attach the rows. This allows wires and components to be inserted into the holes and attached to other components to create circuits. Note, because of the internal connections provided by the breadboard, some projects won’t require any use of wire on your part. The holes in the breadboard are themselves “wired” together.
Resistors
In its simplest form, a resistor provides electrical resistance: it limits the flow of the electrons through the circuit. Resistors are useful for a few reasons. First, allowing electricity to flow from the positive charge to the negative charge without anything to stop it, causes a big safety risk known as a short circuit. The resistor moderates the flow of electrons, so the current doesn’t move too quickly and cause damage to the breadboard, wires, battery, etc. The second reason to use a resistor is to slow the current flow to a component.
Light Emitting Diode (LED)
Diodes are a common electrical component that only allow current to flow in one direction. Light-emitting diodes (LEDs) are a special type of diode that converts electricity into light. They are basically tiny light bulbs that can be used when building an electrical circuit. LED’s are one of the most common components in electrical devices. They are often used to notify users that a device is on.
Each LED has two wires or leads. The short side is the negative side and called the cathode, the positive side is called the anode. Unlike a resistor, LED’s are polarized so they must be aligned correctly in the circuit so electricity flows from positive to negative.
Jumper Wires
While the breadboard provides most of the “wiring” for projects through its internal connection system, occasionally, external wiring is useful for jumping over other components or spanning the distance of the breadboard. Often referred to as jumper wire, the wires included in the Level A kit are specially designed to be inserted into the pins in the breadboard to provide wired connections.
Switches
A switch allows for manual control of an electrical circuit without having to physically disconnect wires or components. This is accomplished by small pieces of conductive metal inside the switch called contacts that connect to each other when you activate the switch. Essentially, a switch controls whether a connection is open, not allowing electricity to pass, or closed, allowing the electricity to flow. Think of it like a drawbridge over a river. When the bridge is open, the cars are unable to cross the bridge. When the bridge is closed, the road is restored and so is the flow of traffic.
Red-Blue-Green Light Emitting Diode (RBG LED)
An RGB LED combines a red LED, a green LED, and a blue LED into one component. This component is capable of emitting red, green, blue, or any combination of those colors.
Together, these simple electronic components can form basic circuits to get you started on learning to work with electronics, write code in Python, and use a Raspberry Pi in Level A of Intro to Robotics.
This blog post on basic electronic components contains short excerpts from the first six lessons of Level A of our Intro to Robotics program. Level A covers building circuits, using a Raspberry Pi, and writing common code commands in Python. It contains 18 lessons including 70+ videos and 45 projects and activities. Sample lessons and a full scope and sequence for Level A can be found here.