Arduino

LEDs (light-emitting diodes) are small, powerful lights that are used in many different applications. In this circuit, an LED is told to repeatedly blink at a constant rhythm.

In this circuit, a potentiometer (dial) is turned which changes the speed the LED blinks. 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 use a RGB LED. 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, a push button is used to turn on a LED. 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.

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 used 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.

In this circuit, we worked with a servo. 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.

In this circuit we worked with a buzzer, using different tones to create songs. We used a buzzer that makes a small "click" when you apply voltage to it. By itself that isn't terribly exciting, but if you turn the voltage on and off hundreds of times a second, the buzzer will produce a tone.

In this circuit we used a motor. The motor requires the use of a transistor, which can switch a larger amount of current than the Arduino can. When using a transistor, we need to make sure its maximum specs are high enough for our use. The transistor we are using for this circuit is rated at 40V max and 200 milliamps max. At this point, we had a hard time getting anything to work and were not able to get this to spin at that time which is why there is no video. Later we finally realized that it was a problem with the Arduino board itself.

In this circuit, A relay is created. The intent was to get the two LEDs to switch at a certain interval. A relay is basically an electrically controlled mechanical switch. Inside that plastic box is an electromagnet that, when it gets a jolt of energy, causes a switch to trip. Same as the last project, we were not able to get this to work at that time, which turned out to be partially due to a faulty Arduino board.

In this circuit, we used an integrated circuit to blink 8 LEDs off and back on. The goal of this circuit was to get the lights to turn on and off in a pattern going down the rows of LEDs. The shift register gave our Arduino an additional eight outputs, using only three pins on our board. Originally, we had a hard time getting it to work, only a couple would light up at a time, but then we tried a new Arduino board and it finally worked.