LEDs (light-emitting diodes) are small, powerful lights that are used in many different applications. To start on this microcontroller, my team and I worked on blinking an LED. It's as simple as turning a light on and off. It might not seem like much, but establishing this important baseline gave us a solid foundation as we worked towards more complex experiments.

In this circuit my team and I worked with a potentiometer. A potentiometer is also known as a variable resistor. When it’s connected with 5 volts across its two outer pins, the middle pin outputs a voltage between 0 and 5, depending on the position of the knob on the potentiometer. In this circuit, we learned how to use a potentiometer to control the brightness of an LED.

You know what’s even more fun than a blinking LED? A colored one. RGB, or red-green-blue, LEDs have three different color-emitting diodes that can be combined to create all sorts of colors. In this circuit, we learned how to use an RGB LED to create unique color combinations. Depending on how bright each diode is, nearly any color is possible!

So you have gotten one LED to blink on and off- fantastic! Now it's time to up the stakes a little bit by connecting EIGHT LEDS AT ONCE. We'll also give our Arduino a little test by creating various lighting sequences. This circuit is a great setup to start practicing writing your own programs and getting a feel for the way Arduino works. Along with controlling the LEDs, you’ll learn about a couple programming tricks that keep your code neat and tidy: for() loops - used when you want to run a piece of code several times arrays[ ] - used to make managing variables easier by grouping them together.

Up until now, my team and I focused solely on outputs. Now we went to the other end of spectrum and played around with inputs. In this circuit, we looked at one of the most common and simple inputs – a push button. The way a push button works with Arduino is that when the button is pushed, the voltage goes LOW. The Arduino reads this and reacts accordingly. In this circuit, we also used a pull-up resistor, which helped clean up the voltage and prevents false readings from the button.

We have now already played with a potentiometer, which varies resistance based on the twisting of a knob. In this circuit, we used a photo resistor, which changes resistance based on how much light the sensor receives. Since the Arduino can’t directly interpret resistance (rather it reads voltage), we use a voltage divider to use our photo resistor. This voltage divider will output a high voltage when it is getting a lot of light and a low voltage when it is not.

A temperature sensor is exactly what it sounds like – a sensor used to measure ambient temperature. This particular sensor has three pins – a positive, a ground, and a signal. For every centigrade degree it reads, it outputs 10 millivolts. In this circuit, We learned how to integrate the temperature sensor with our Arduino, and use the Arduino IDE’s debug window to display the temperature.

Servos are ideal for embedded electronics applications because they do one thing very well that spinning motors cannot – they can move to a position accurately. By varying the pulse of voltage a servo receives, we were able to move a servo to a specific position. For example, a pulse of 1.5 milliseconds will move the servo 90 degrees. In this circuit, we learned how to use PWM (pulse width modulation) to control and rotate a servo.

In this circuit, we once again managed to bridge the gap between the digital and analog world. My team and I used a buzzer for this project that can make music by stringing together hundreds of little clicks.

Remember before when we played around with a servo motor? Now we are going to tackle a spinning motor. This requires the use of a transistor, which can switch a larger amount of current than the Arduino can. When using the transistor, I just needed to make sure the max specs were high enough for this circuit.

In this circuit, we used some of the lessons from previous circuits to control a relay. A relay is just an electrically controlled mechanical switch. Inside it's harmless looking plastic box is an electromagnet that, when provided the energy, can cause a switch to trip. In this circuit, we learned how to control a relay like a pro.

Next, we stepped into the world of ICs. In this circuit, we learned to use a shift register. This gave our Arduino an additional eight outputs, using only three pins on the board. For this circuit, we practiced using the shift register to control eight LEDs.