Have you just bought an Arduino starter kit, or are you hesitant to buy one because you're not quite sure what's in it? You're not alone. Faced with a box full of electronic components, it's easy to be overwhelmed.The S Kit contains 250+ electronic components for use in your own Arduino projects. Here's a guide to exactly what these components are and how you can use them.

What's Included in an Arduino Starter Kit?

We're using the SunFounder Starter Project Kit for Arduino, available for $49, which is fantastic value for money. Even if you have a different starter kit, it's likely you'll find some (but not all) of the same components, so this guide should still be useful to read.

You should also note that this starter kit has changed over the years. So, if you have an older version, there may be a few differences, but the core components should remain relatively the same.

Arduino Mega

arduino-mega-2560-board
Image Credit: Arduino Store

The most important piece of the kit is the Arduino board itself. The model in the SunFounder kit is actually an unofficial Arduino Mega 2560 clone, but that shouldn't make too much of a difference. There are certain pros and cons of using an Arduino clone that you should keep in mind. Since the Arduino design is open source, it's perfectly legal for other companies to reproduce or modify it as long as they don't brand it as an official "Arduino" board.

Breadboard

arduino-breadboard

A breadboard is a tool used to experiment with circuits without the need for soldering wires. In essence, it's a temporary testing tool with which you can make and break electrical connections quickly. The breadboard consists of a sheet of plastic with holes on the top, and metal rails connected underneath; components and jumper wires are inserted into these holes. Each of those rows of five holes in the middle is connected. The entire column is connected on the outside: these are typically used as power lines to connect to external power sources.

Using a breadboard in your projects makes it much easier to get started with tinkering and allows you to test your ideas at the initial stage.

LEDs

arduino-led

The SunFounder kit comes with several LEDs in various colors (red, yellow, green, blue, and white) as well as a single RGB LED. The RGB LED features four pins (one for each color and one common cathode, or ground), so you can experiment with color mixing, or create displays of random colors. It's quite cool to play with once you dive into programming with Arduino. Beginners, especially, tend to be fascinated with how much you can achieve with a few lines of code.

One important thing to note is the leads on the LED. Typically, the positive one is longer than the negative, but if yours are the same size, then look for a flat side on the base of the actual LED. The leg on the flat side is the ground or negative.

You can unleash your creativity with LEDs. For a list of interesting ideas, be sure to check our list of inspiring Arduino LED projects you can make yourself.

USB Cable

arduino usb cable

The USB cable connects your Arduino to your PC or a separate power supply. In addition to providing power to the unit, the cable transmits data—in the form of programs, or "sketches"—between the PC and Arduino. Once uploaded, the Arduino stores the program even if it's disconnected from power. To erase the program on an Arduino, you just upload a new one.

While the Arduino will store your program indefinitely, even without power, it's important to note that the board needs to be connected to a power source of some kind to run it. It can be powered from a USB port, wall charger, or a 9V or 12V DC input.

Ceramic Capacitor (100nF)

arduino ceramic capacitor

Capacitors store and discharge energy: they're generally used to regulate voltage or smooth out a signal. A specific example of this is "debouncing" a button press. While pressing a button may seem like a simple, quick action to you, on an electrical level it can in fact generate a series of very quick high and low electrical noise. Debouncing is the process of smoothing this so that a single button press is just that.

For a more in-depth guide to capacitors, read our guide on what capacitors are and what they are used for.

H-Bridge (L239D)

An Arduino H Bridge

An H-Bridge is an integrated circuit that allows voltage to be applied in either direction. These are typically used in conjunction with a DC motor to allow it to spin both forward and backward. The L239D IC that comes in the SunFounder Starter Kit is actually a dual H-Bridge, so you can drive two DC motors (great for robots) or a single stepper motor.

DC Motor

arduino-dc-motor

A DC motor is a component containing a metal rod that spins when connected to power. The spinning rod can then do simple things like spinning a fan, or running a pulley system that creates motion (in an RC car, for example).

Stepper Motor

A stepper motor is a special type of DC electric motor used for precise control of position and rotation. Steppers are used in applications that require accurate positioning and where there is no need for back-and-forth motion. The stepper motor converts electrical input signals into discrete steps, each step being a uniform angular distance. There are two basic types of stepper motors: unipolar and bipolar stepper motors.

Servo Motor

The rotary servo in the kit contains a DC motor, potentiometer, and gearing system that can be used for precision control of the position of its "horn" using PWM (pulse-width modulation) signals from the Arduino. Servos may be used in devices such as robotic arms and steering systems.

5V Relay

The SunFounder Kit used to include an optocoupler, but that has since been replaced with a 5V relay. A relay is an electromechanical switch that allows you to close and open circuits without mechanical contact.

Optocouplers are typically cheaper, more reliable, and faster than a relay, but they are also incapable of handling higher loads. Relays come in handy when you need to control a large amount of current or voltage using a small electrical signal.

Resistors

Sunfounder Kit Arduino Resistors

Resistors are components that limit the flow of current to other components. When you plug a wire into the 5V power pin on an Arduino, but a component can only handle 3.5V, you need to find a way to restrict the amount of power (current) it receives in order to avoid damaging it.

The water pipe analogy is one of the best ways to describe the operation of a resistor. If you think of a circuit as a network of water pipes flowing in one direction, a resistor would be like connecting a smaller pipe to the end of a larger one. The main reason for doing this would be to protect the other components from damage.

The resistors in this starter kit come in various values (from 220Ω up to 1MΩ). This can be confusing if you are not familiar with resistor color codes, but the important thing to remember is that the colored bands hold all the information you need in determining the value of each resistor: check out our guide on how to read resistor color codes.

Thermistor

A thermistor is a resistor whose resistance is highly dependent on temperature, more so than standard resistors. It is made up of highly conductive materials. Thermistors are subdivided into two classes: Negative Temperature Coefficient (NTC) thermistors and Positive Temperature Coefficient (PTC) Resistors. The resistance of an NTC thermistor decreases with temperature, while that of a PTC resistor increases.

Photoresistor

A photoresistor, also known as a light-dependent resistor (LDR), is an electronic component that changes its electrical resistance in response to the intensity of light. The resistance of a photoresistor decreases as the amount of light that falls on it increases, and vice versa.

Photoresistors are often used in electronic circuits as sensors for detecting changes in ambient light levels and are commonly found in light-sensitive devices such as streetlights, cameras, and automatic nightlights.

7-Segment Display

arduino 7 segment display

A 7-segment display is an integrated package of LEDs that act as a digital readout for projects that need a display of numbers. The SunFounder Kit includes both a single-digit and four-digit version. While it can't handle images or the like, this kind of display is ideal for projects such as electric dice, an alarm clock, or even a countdown timer.

Humiture Sensor

The digital humiture sensor contained in this kit, a DHT11, is a composite sensor that measures both the relative humidity and temperature of the surrounding area. These sensors are commonly used in environmental monitoring and control systems, as well as in various industrial and scientific applications where accurate measurements of humidity and temperature are important.

Potentiometer

Arduino Potentiometer

Though visually similar to a rotary encoder, a potentiometer has a fixed range of motion and produces an easy-to-read analog output to show exactly where it's been rotated to. The main difference is that a potentiometer has a fixed start and end point, and often a shorter life span. A potentiometer may be better suited for projects that don’t require exact precision, such as controlling LEDs or servo motors.

Shift Register

Arduino Shift Register

A shift register is a kind of short-term memory chip that receives data in series, then "shifts" it all out once. In practical terms, this means you can free up I/O pins on the Arduino. Crucially, shift registers can also be daisy-chained together, allowing you to drive many more outputs than would otherwise be possible. They're a bit harder to program, but they can come in handy in Arduino projects that require delay or pulse stretching. The SunFounder kit includes a 74HC595 8-bit shift register.

LCD Screen

arduino lcd display

The LCD screen features a 16x2 character display that can show static or scrolling messages. Typically, you'd use this to output sensor readings or any other simple text readout. Be warned, though: the display uses up a lot of output pins on the Arduino, so you will only have a few left to play with after hooking it up.

PS2 Joystick

The Joystick PS2 module in this kit has analog outputs for the X and Y axes, along with a digital output for when you press the joystick down. It can be used in robotics and gaming projects.

Transistors (NPN)

Arduino Transistor

Transistors are the foundation of modern electronics. Both PNP (positive, negative, positive) and NPN (negative, positive, negative) transistors are controlled by electrical current and act as a digital switch—used in digital logic and signal-amplifying circuits. Each type of transistor has a base, collector, and emitter. The kit includes two NPN transistors.

While PNP and NPN are nearly identical, the difference is that they have completely opposite polarities. The PNP flows out, from the emitter to the connector. The NPN flows in, from the collector to the emitter. If you need a simple mnemonic, remember this: NPN = Not Pointing iN.

Push Buttons

Arduino Push Button

A push button is a simple tactile switch that makes or breaks electrical contact when pressed. This can be used to initiate a variety of different effects depending on the project. For example, you could roll dice (for display on an LCD or dot matrix), sound a piezo buzzer, or start/stop a LED light show. The kit includes five push buttons.

Diodes

Arduino Diode Rectifier

A diode lets electrical current flow in only one direction. Typically, this is used to protect components or circuits from reverse current surges, such as from a motor that continues to turn after the power has been switched off. The kit includes a 1N4007 diode.

Jumper Wires

arduino-jumper-wires

Jumper wires are for making connections on the breadboard, as well as from the breadboard to the Arduino itself. The starter kit includes male-to-male and male-to-female jumpers in several shades. Although the color doesn't matter, it's a great way to organize your project’s connections; you may want to adopt the rule of using red for +ve power, and black for ground, since that's a universal standard (but it doesn't affect functionality).

Piezo Buzzer

Arduino Piezzo buzzer

A piezo buzzer is basically a tiny speaker that can beep in different tones. They come in two types: active and passive. The active buzzer included in the kit emits a solid tone whenever it's connected to power, but you can program it within the code to change the length and frequency of the sounds emitted.

Getting Started With an Arduino Starter Kit

This should give you an idea of what the components in your kit are, and how they can be used in electronics projects. Whether you're new to electronics or just new to using the Arduino development platform, a starter kit is a great way to get started with Arduino. It comes with all the tools you need to start building your own projects and learning about electronics. Some reviews of this product contain complaints about the attached instructions and how they are unclear/outdated. However, most buyers claim to be happy with the purchase, regardless of these issues.