Have you just bought a starter kit or are hesitant to buy it because you’re not quite sure what’s in it? You’re not alone. Faced with a box full of electronic components, it is easy to break. Here’s a guide to exactly what you’ll find in your kit.
We use the SunFounder UNO starter kit, available at $49.99, which we recommend for its fantastic value for money. If you have a different starter kit, chances are you’ll find some (but not all) of the same components, so it’s still a good read. You can also check our Beginner Electronics Skills for Beginners article.
What is included in the Arduino starter kit?
Arduino Uno
The most important part of the kit is the Arduino myself. Uno is one of the most basic models, but for a beginner it is completely serviceable and there is almost nothing that can be done with it. Whether you’re looking for larger or more powerful models, the Arduino Mega fits the bill; while for projects that require the use of very small spaces, the Mini or Pro Micro should be more than adequate.

The model in the Sunfounder kit is actually informal a clone of Uno. Because the Arduino design is open source, it is legal for other companies to reproduce or modify it as long as they don’t label it as an official «Arduino» board.
mock up
A breadboard is a tool used to experiment with circuits without the need for soldering wires. Basically, it’s a timing test tool with which you can quickly make and break electrical connections. The breadboard consists of a sheet of plastic with holes at the top and metal rails connected at the bottom: components and connecting wires are inserted into these holes. Each of these rows of 5 holes in the middle is connected. Outside, the entire column is connected: they are usually used as common power lines.
LEDs
The Sunfounder kit comes with several LEDs in different colors (red, yellow, green and white) as well as one RGB LED. The RGB LED has 4 pins (one for each color and one common cathode — or ground) so you can experiment with mixing colors or create random color displays. Very cool to play after you dive into the code. In fact, it was very satisfying for a beginner to see instant results when I edited my first bits of the Arduino code.
One important thing to note is the pins on the LED. Generally, the positive is longer than the negative, but if you have the same size, look for the flat side based on the actual LED. The foot on the flat side is ground or negative.
USB cable
The USB cable connects to your Arduino as well as your PC or a separate power supply. In addition to supplying power to the device, the cable transfers data—in the form of programs or sketches—from the PC to the Arduino. Once loaded, the Arduino retains information even if it is powered off. To erase a program, you simply download a new one.
Although the Arduino will store your program indefinitely, even without power, it is important to note that the board itself does not have a power source, so it will not work unless it is connected to some kind of power source. In addition to being powered by a USB port or wall charger, a 9V or 12V DC input can be used.
40 pin connector
This is a series of 40 pins that can be broken or cut to any size. Components often come with pins, but if you’ve bought something that only has holes, then a solder pin can be soldered on to make it easier to work with on a breadboard.
Ceramic Capacitor (10nF and 100nF)
Capacitors store and discharge energy: they are commonly used for voltage regulation or signal smoothing. A specific example of this is «cancelling» a button click. Although pushing a button may seem like a simple quick action to you, on an electrical level it can generate a series of very fast high and low electrical noise. Debouncing is a smoothing process, so pressing one button is easy.
H bridge (L239D)
The H-bridge is an integrated circuit that allows voltage to be applied in either direction. They are usually used in conjunction with a DC motor to allow it to rotate both forward and reverse. L239D is actually double bridge H so you can control two motors, which is useful when building simple robots.
accelerometer
Accelerometers are designed to measure acceleration and tilt along one to three linear axes (x, y, z). Although it does many things, it is commonly used to measure distance, lateral movement, and sudden stops and starts of all types of devices. For example, if you have a device that only moves in one direction, such as a robot following a line, then the accelerometer allows you to get a reading of the distance traveled, taking into account acceleration and time to measure the distance traveled by the element.
DC motor
A DC motor is a component containing a metal rod that rotates when connected to a power source. The rotating rod can then perform simple actions such as spinning a fan or starting a pulley system that creates movement (like in an RC car).
optocoupler
An optocoupler allows a signal to be passed between two parts of a circuit while keeping them electrically isolated. Internally, it’s just an LED with a photoresistor. Conceptually, they are very similar to relays, but differ in a number of ways:
- They are smaller and lighter than relays.
- It is a solid state, which means there are no moving parts and therefore offers fewer opportunities for failure.
- Less current is required to activate than a relay; but, conversely, only small amounts of current can be switched.
Resistors (220, 1k, 10k, 1M, 5.1m Ohm)
Resistors are components that limit the flow of current to other components. When you connect a wire to the Arduino’s 5V power jack, but the component can only handle 3.5V, you need to find a way to limit the amount of power (current) it receives to avoid damage.