Day 4 - Intro to Transistors and Arduino

• This lab explored how transistors work and required us to assemble several systems with transistors and programmed by the Arduino

1. A transistor is very similar to a relay. There are three pins in a transistor and the pins serve as a collector (where positive electricity flows), base(where electricity may travel to), and emitter (where ground electricity flows). This photo is a visual representation of how electricity flows in both types of transistors PNP and NPN.
2.  We utilized the capabilities through this assembly. 
   
3. Next, we removed the push button and used a human finger as a conductor for the electricity to pass through. It may difficult to tell from the video but when the finger is wet the light shone brighter.
4. For this next part we used a potentiometer and a variable screw resistor to change the current flowing through the transistors. In this picture A1 is on the right side and A2 is on the left side.. Similarly, in this picture A1 is on the right side and A2 is on the left side. 
5. We started at a low current and slowly increased the amount of current that could pass into the transistor. The relationship that was discovered was that the more low the milli amps that were permitted to travel through A1 the higher the gain was measured. Keep in mind that gain = (A2 current) /(A1 current).

• Introduction to Microcontrollers

1. Here is the LED flashing band. For the next part we designed and powered 4 led lights and cycled them continuously. 
1. video

1. code

void setup() {

  pinMode (13, OUTPUT) ; //Initialize Digital Pin 13 as an output

  pinMode (12, OUTPUT) ; //Initialize Digital Pin 12 as an output

  pinMode (7, OUTPUT) ; //Initialize Digital Pin 7 as an output

  pinMode (3, OUTPUT) ; //Initialize Digital Pin 3 as an output

}

void loop () {

  digitalWrite (13,HIGH) ; //Set the LED On

  delay (100);           //Wait for 1000 ms (1 Second)

  digitalWrite(13,LOW);  //Set the LED off

  delay (1000);   //Wait for 1 second

  

  digitalWrite (12,HIGH) ; //Set the LED On

  delay (100);           //Wait for 1000 ms (1 Second)

  digitalWrite(12,LOW);  //Set the LED off

  delay (1000);   //Wait for 1 second

    digitalWrite (7,HIGH) ; //Set the LED On

  delay (100);           //Wait for 1000 ms (1 Second)

  digitalWrite(7,LOW);  //Set the LED off

  delay (1000);   //Wait for 1 second

    digitalWrite (3,HIGH) ; //Set the LED On

  delay (100);           //Wait for 1000 ms (1 Second)

  digitalWrite(3,LOW);  //Set the LED off

  delay (1000);   //Wait for 1 second

    digitalWrite (7,HIGH) ; //Set the LED On

  delay (100);           //Wait for 1000 ms (1 Second)

  digitalWrite(7,LOW);  //Set the LED off

  delay (1000);   //Wait for 1 second

    digitalWrite (12,HIGH) ; //Set the LED On

  delay (100);           //Wait for 1000 ms (1 Second)

  digitalWrite(12,LOW);  //Set the LED off

  delay (1000);   //Wait for 1 second

}