Lab 4: Data Storage and RC servos

During this lab, we wanted to be able to use the EEPROM.read and EEPROM.write functions to store data in the Arduino so that it could be used later on in different studies. However, the one danger in doing this is that if the code is written in an endless loop, then it is very possible to fry the Arduino

#include <EEPROM.h>
void setup() {
Serial.begin(9600);
}
int value = 0;
int address = 0;

void loop() {
int inputChar;
if (Serial.available() > 0){
  inputChar = Serial.read();
   
    if (inputChar == 'w')
    {
        EEPROM.write(address, value);
        address=address+1;
        value=value+2;
    }
}
}

Additionally, we tried to build an angle positioning device by using an RC servo motor plugged into the Arduino. The angle of the servo motor is controlled by the length of pulses sent to the servo from the Arduino. Each of the pulses must be sent in 20ms intervals.

void setup() {
Serial.begin(9600);
pinMode(4,OUTPUT);
}

void loop() {
 
int inputChar;
int inputNumber;
int inputNumber2;
inputNumber = 0;

if (Serial.available() > 0) {
      delayMicroseconds(5000);
      while (Serial.available() > 0) {
        inputChar = Serial.read();
        inputNumber2 = inputNumber * 10 + (inputChar-48) ;
      
       
        if (inputNumber2 == 1)
          Serial.println ("180");
        digitalWrite(4,HIGH);
 
              delayMicroseconds(2000);
            digitalWrite(4,LOW);
 
              delay(18);

if (inputNumber2 == 9)
          Serial.println ("90");
        digitalWrite(4,HIGH);
 
              delayMicroseconds(1500);
            digitalWrite(4,LOW);
 
              delayMicroseconds(19000);

if (inputNumber2 == 0)
          Serial.println ("0");
        digitalWrite(4,HIGH);
 
              delayMicroseconds(1000);
            digitalWrite(4,LOW);
 
              delayMicroseconds(19000);
      }
    }
}

Lab 3: Serial.read and ColorPal

The first part of this lab was to learn how to use the serial.read command. We simply wanted to plug in a command ("a" for instance) and have the arduino output a result in the serial monitor using the following code:

 void setup() {
Serial.begin(9600);
}

void loop() {
int inputChar;
if (Serial.available() > 0){
  inputChar = Serial.read();
 
    if (inputChar == 'a')
    {
        Serial.println("This is a");
    }
    if (inputChar == 'b') {
        Serial.println("This is b");
  }
}
}

The second thing we wanted to do was for the Arduino to read a number from the serial monitor. However, since the Arduino works in a way where certain numbers and letters are coded in addition to the fact that the inputs must be multiplied by 10 to shift to the right, we had to use an altered code. This is because instead of the number 23, the arduino would read 5 because it adds the 2 numbers together. We wanted to shift the 3 to the right before adding the 2 so that we can get the output 23, rather than 5:

void setup() {
Serial.begin(9600);
}

void loop() {
 
int inputChar;
int inputNumber;
inputNumber = 0;

if (Serial.available() > 0) {
      delay(5);
      while (Serial.available() > 0) {
        inputChar = Serial.read();
        inputNumber = inputNumber * 10 + (inputChar-48) ;
        Serial.println(inputNumber);
       
      }
    }
}

Another thing we did was to use the input from the keyboard in addition to the tone function to use the keyboard commands to produce different notes on the Arduino. This essentially turned the computer keyboard into a musical keyboard:

 void setup() {
Serial.begin(9600);
}

void loop() {
int inputChar;
if (Serial.available() > 0){
  inputChar = Serial.read();
 
    if (inputChar == 'a')
    {
        Serial.println("A");
        tone(3,440,1000);
    }
    if (inputChar == 'b') {
        Serial.println("B");
        tone(3,494,1000);
  }
  if (inputChar == 'c') {
        Serial.println("C");
        tone(3,523,1000);
  }
}
}

ColorPal

The ColorPal is a color measuring module that when connected to the Arduino, can be placed to any surface and measure the red, green and blue components of the color of that surface. For our intensive purposes, we first wanted to connect the ColorPal and get it working. Afterwards, we wanted to be able to have the ColorPal detect the color of a surface and output that color in the serial monitor after analyzing the RGB values. We first had to measure the black and white color levels to essentially "zero" the device:

#include <SoftwareSerial.h>
SoftwareSerial Color90(2, 3);  // rx = 2, tx = 3

int red;
int grn;
int blu;

int gotcolor = 0;
int letter;

void setup()
{
  Serial.begin(9600); // Start communication with serial port read value
  Color90.begin(4800); // Send signal to led to read value

  pinMode(2,INPUT); // serial pin out from color pal
  pinMode(3,INPUT); // from same serial pin, signal pulls up, sends, pulls down, reads
  digitalWrite(2,HIGH); // Enable the pull-up resistor
  digitalWrite(3,HIGH); // Enable the pull-up resistor

  pinMode(2,OUTPUT); // send signal out
  pinMode(3,OUTPUT);
  digitalWrite(2,LOW); // turn pin off so pin 3 can go high
  digitalWrite(3,LOW);

  pinMode(2,INPUT); // Input signal to print
  pinMode(3,INPUT);

  Serial.println("Pass 1");

  while( digitalRead(2) != HIGH || digitalRead(3) != HIGH ) {
    Serial.println("In the loop");
    delay(50);
  }

  Serial.println("Pass 2");

  pinMode(2,OUTPUT);
  pinMode(3,OUTPUT);
  digitalWrite(2,LOW);
  digitalWrite(3,LOW);
  delay(80);

  pinMode(2,INPUT);
  pinMode(3,OUTPUT);
  delay(100);

}

// This oscillates back and forth on one wire to turn off led, send signal,
// turn on led, read signal. very fast strobe read - arduino is not capable of
// one wire signal communication over digital ports, so this is a way around
// that over 2 wires communicating with 1 pin on the sensor.
//---------------------------------



void loop()
{
  readcolor();
  Serial.print("R");
  Serial.print((red - 23)*0.96226);
  Serial.print("   G");
  Serial.print((grn - 26)*0.78704);
  Serial.print("   B");
  Serial.print((blu - 31)*0.63591);
  Serial.print("   Color: ");
 
  int sum = (((red - 23)*0.9622) + ((grn - 26)*0.78704) + ((blu - 31)*0.63591));
 
  if (sum <=-50)
  Serial.print("Blank");
  if (sum >250)
  Serial.print("White");
  if (sum >-50 && sum <=4)
  Serial.print("Black"); 
  if (sum >4 && sum <=250 && red > blu && red > grn)
  Serial.print("Red");
  if (sum >4 && sum <=250 && grn > blu && grn > red)
  Serial.print("Green");
  if (sum >4 && sum <=250 && blu > red && blu > grn)
  Serial.print("Blue");
 
  gotcolor = 0;
  delay(100);

}
void readcolor() {  // Reads ColorPAL, putting results in the red,grn,blu variables

  char rByte[9];
  char dummy[4];

  delay(20);
  Color90.begin(4800);
 Color90.print("= (00 $ m) !");  // set up loop to continuously send color data
  pinMode(3,INPUT);
  gotcolor = 0;
  while (gotcolor == 0) {
    rByte[0] = Color90.read();
    if( rByte[0] == '$' ) {
      gotcolor = 1;
      for(int i=0; i<9; i++) {
        rByte[i] = Color90.read();
//        Serial.print(rByte[i]);
      }
      Serial.println("");
      dummy[0] = rByte[0];
      dummy[1] = rByte[1];
      dummy[2] = rByte[2];
      dummy[3] = 0;

      red = strtol(dummy,NULL,16);

      dummy[0] = rByte[3];
      dummy[1] = rByte[4];
      dummy[2] = rByte[5];

      grn = strtol(dummy,NULL,16);

      dummy[0] = rByte[6];
      dummy[1] = rByte[7];
      dummy[2] = rByte[8];

      blu = strtol(dummy,NULL,16);
    }
  }
}


 

Lab 2

In this lab, we focused on using the microcontroller to measure both inputs and outputs. First, we determined how to generate a ramp output and a sine wave and displayed them both in StampPlot. Additionally, we learned how to output these functions into the Oscilloscope.


Sine Wave

void setup() {

Serial.begin(9600);

}

float x=0;

void loop()

{

Serial.println(sin(x));

x+=0.1;

delay(10);

}

Square Wave

int period;

void setup() {

pinMode(12,OUTPUT);

period = 10;

}

void loop()

{

  digitalWrite(12,HIGH);

 

delay(period);

  digitalWrite(12,LOW);

 

delay(period);

}

We also focused on creating a program that measured how fast the user could tap their finger:

void setup() {

Serial.begin(9600);

pinMode(12,OUTPUT);

void loop(){

digitalWrite(12,HIGH);

digitalRead(12);

float x=digitalRead(12);

Serial.println(x);

delay(10);

}

Tones

int melody[] = {NOTE_C4, NOTE_G3,NOTE_G3, NOTE_A3, NOTE_G3,0, NOTE_B3, NOTE_C4};

// note durations: 4 = quarter note, 8 = eighth note, etc.:

int noteDurations[] = {4, 8, 8, 4,4,4,4,4 };

void setup() {

  // iterate over the notes of the melody:

  for (int thisNote = 0; thisNote < 8; thisNote++) {

    // to calculate the note duration, take one second

    // divided by the note type.

    //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.

    int noteDuration = 1000/noteDurations[thisNote];

    tone(8, melody[thisNote],noteDuration);

    // to distinguish the notes, set a minimum time between them.

    // the note's duration + 30% seems to work well:

    int pauseBetweenNotes = noteDuration * 1.30;

    delay(pauseBetweenNotes);

    // stop the tone playing:

    noTone(8);

  }

}

void loop() {

  // no need to repeat the melody.

}