Assignment: Sensing: Potentiometers

Collaborators:

Assignment: Sensing: Potentiometers
Collaborators:

Assignment: Sensing: Potentiometers
Collaborators:

Description

For this lab, I followed the directions given in class. In addition, I added an additional LED and pot I had at home. I reused my diffuser with cotton (instead of a packing peanut) from the last assignment.

More information about the code and additional parts for the assignment are described below.

Components Used

• x4 220 Ohm resistors
• x4 LEDs - red, green, yellow, and blue
• x4 Potentiometers
• Wires
• 1 Arduino NG board
• Cosmetic Cotton Squares
• Dosage cup from Vick's Dayquil Medicine

Code + Extras

For the assignment, I wired up four different colored LEDs (RGBY). Using the arduino programming language, I wrote code that associated a potentiometer for each LED.

For the "interesting" portion of the assignment, I set a threshold value midway through the pot. From 0 to 127, the LED starts from OFF (analog value 0) and increments up to fully on (analog value 255). Once the pot reaches the midway point, it begine to flash rapidly. Adjusting the pot higher will continue to slow down the rate of blinking.

Here is a text diagram of what is going on:

Analog Value: 0 -------------------------------------- 127 -------------------------------------- 255

LED:              | Off -------> + intensity -------> Full || (fast blink) ---> - blink rate ---> (slow blink)|

Images

Source Code

// Analog pin settings

int aIn = 0, bIn = 1, cIn = 2, dIn = 3;

// Digital pin settings

int aOut = 6, bOut = 9, cOut = 10, dOut = 11;

// Pot Values

int aVal = 0, bVal = 0, cVal = 0, dVal = 0;

// Variables for comparing values between loops

int i = 0;            // Loop counter

int wait = (1000);    // Delay between most recent pot adjustment and output

int blinkDelay = 0;   // Blink delay

int checkSum     = 0;

int prevCheckSum = 0;

int sens         = 3; 

void setup()

{

  pinMode(aOut, OUTPUT);

  pinMode(bOut, OUTPUT);   

  pinMode(cOut, OUTPUT);

  pinMode(dOut, OUTPUT); 

  Serial.begin(9600);     // Open serial communication for reporting

}

void loop()

{

  i += 1; // Count loop

  aVal = analogRead(aIn) / 4;  // read input pins, convert to 0-255 scale

  bVal = analogRead(bIn) / 4; 

  cVal = analogRead(cIn) / 4;

  dVal = analogRead(dIn) / 4;

  doCheck(aOut, aVal);

  doCheck(bOut, bVal);

  doCheck(cOut, cVal);

  doCheck(dOut, dVal);

  if (i % wait == 0)

    prevCheckSum = checkSum;  // Update the values

}

// Determine whether to blink or change intensity

void doCheck(int pin, int value)

{

  if (value == 0)

    digitalWrite(pin, LOW); 

  else if (value <= 127)

    doIntensity(pin, value*2); 

  else

    doBlinking(pin, value);

}

// Adjust Intensity

void doIntensity(int pin, int value)

{

  analogWrite(pin, value);

}

// Adjust Blink Rate

void doBlinking(int pin, int blinkDelay)

{

  digitalWrite(pin, HIGH);

  delay(blinkDelay); 

  digitalWrite(pin, LOW);

  delay(blinkDelay);      

}