Final images

Detail photos

Final project movies

A video of Janelle using the color red on a phone to move it in front of the color sensor, causing the rest of the components to react

A video of Ana using the color red on a phone to start the circuit. Shows the whole double transducer working as well as the skip the middle video. 

Narrative description

To put it simply, we take in the color red, which makes an umbrella cover a light sensor. Once the light sensor gets enough shade, it begins to make a linear actuator with a magnet on the end of it move back and forth. This will create a DIY magnetic field!

In more detailed languaged, this is our Double Transducer that takes in light color as the input and outputting a magnetic field. The middle step includes a servo motor that controls an umbrella that, when given the color red, would move and provide shade to a photoresistor. Once the photoresistor receives enough shade, a linear actuator with a magnetic attached to the end of the actuator begins to move back and forth. This would then creator our magnetic field output. 

Progress images

Discussion

We found that the easier parts were figuring out the wiring between components and how to connect them to one another. Since we already did some practice in class as well as from the videos we watched on Canvas, it was fun to connect the pieces together in our project. 

However, everything else was relatively hard! There was a steep learning curve in understanding what we needed to make and create in such a short amount of time. From the beginning, we had a tough time just researching how to do our input (light color) and our output (creating a magnetic field). For example, we spent a good hour or so just doing research on light color and the specific component we had to use (the APDS-9960). There was no documention on it in ioref. Thus, this sent us on a wild goose chase finding the particular part, any example code, and figure out the wiring schematic. This experience taught us to do research on components effectively and how to understand components that do not exist on ioref. 

We also found it pretty difficult to code the linear actuator and how to measure the 'magnetic field' that was being created such that it can be displayed on our LCD Display. Because there is no definite way to measure the distance of the actuator moving back and forth, we had to create an 'internal clock' for it where we would define a middle state distance and, once the actuator exceeds that distance, it should move back and then forth, etc.. It was a pretty tough coding challenge and we were unable to complete it. But, from this experience, we learned a lot about how we should structure our code such that its easier for us to debug.

If we were to make a little tweak, we could have started a lot earlier and received more debugging help at the beginning. If we did that, then we probably would have figured out the linear actuator component quicker. Side note, if I (Janelle) were to be present during the final days of submission it would have tremendously helped in our efforts in finishing the project. I would like to thank Ana for working with Zach and Ella with debugging and reconstructing the code I was working on. Thanks :)

Functional block diagram and electrical schematic

Code

/*

    Double Transducer: Light Color to Magnetic Field

    The Double Transducer follows these steps:

      1) read light color as input, specifically the color red

      2) as the level of the color red increases, the servo motor with an umbrella moves 

      3) the umbrella covers a photoresistor

      4) once the photoresistor receives enough shade, it triggers the linear actuator to move

      5) the linear actuator has a magnet attached at the end, the horizontal movement allows for a magnetic field to be created

      6) if the red light level goes below its needed threshold, the linear actuator retracts 

    Note:

When a button is held down, it skips the middle step

where the middle step is the servo motor and photoresistor.

    Pin mapping:

    Arduino pin | role  | details

    ------------------------------

    6             input   momentary button

    A3            output  photoresistor 

    8   output  servo motor

    10            output  linear actuator A

    11            output  linear actuator B

    Released to the public domain by the authors, January 2024

    Ana Diaz-Yong, adiazyou@andrew.cmu.edu &&

 Janelle Tecson, jtecson@andrew.cmu.edu

*/

/*************************************************************

    [ 1 ] read inputs (gather information from the world)

*************************************************************/

// Libraries

#include <Servo.h>

#include <Wire.h>  // color sensor

#include <SparkFun_APDS9960.h>

#include <LiquidCrystal_I2C.h>

// Define Liquid Screen

LiquidCrystal_I2C screen(0x27, 16, 2);

// Arudino Run Time

unsigned long HALFSECONDWAIT = 500;  // 500 milliseconds is half a second

unsigned long nexttimetorun = 0;

// Defining Pins

int currentdistance = 0;

Servo umbrellaMotor;

const int PHOTOPIN = A3;

const int UMBRELLAMOTORPIN = 8;

const int LINEARACTUATORA = 11;

const int LINEARACTUATORB = 10;

const int BUTTONPIN = 6;

// Global Variables

//color sensor

SparkFun_APDS9960 apds = SparkFun_APDS9960();

uint16_t ambient_light = 0;

uint16_t red_light = 0;

uint16_t green_light = 0;

uint16_t blue_light = 0;

void setup() {

 //make same order normally

 pinMode(LINEARACTUATORA, OUTPUT);

 pinMode(LINEARACTUATORB, OUTPUT);

 pinMode(PHOTOPIN, INPUT);

 umbrellaMotor.attach(UMBRELLAMOTORPIN);

 pinMode(BUTTONPIN, INPUT);

 Serial.begin(9600);

 // Code to get sensor started [https://learn.sparkfun.com/tutorials/apds-9960-rgb-and-gesture-sensor-hookup-guide/all]

 if (apds.init()) {

   Serial.println(F("APDS-9960 initialization complete"));

 } else {

   Serial.println(F("Something went wrong during APDS-9960 init!"));

 }

 // Start running the APDS-9960 light sensor (no interrupts)

 if (apds.enableLightSensor(false)) {

   Serial.println(F("Light sensor is now running"));

 } else {

   Serial.println(F("Something went wrong during light sensor init!"));

 }

 // Wait for initialization and calibration to finish

 delay(500);  // this may be an issue

 screen.init();

 screen.backlight();

 screen.home();

}

void loop() {

/*************************************************************

    [ 1 ] read inputs (gather information from the world)

*************************************************************/

 int photoVal = analogRead(PHOTOPIN);

 int buttonVal = digitalRead(BUTTONPIN);

 delay(250);

// safety check

 if (!apds.readAmbientLight(ambient_light) || !apds.readRedLight(red_light) || !apds.readGreenLight(green_light) || !apds.readBlueLight(blue_light)) {

   Serial.println("Error reading light values");

 }

/*************************************************************

    [ 2 ] using gathered data to change different variables

*************************************************************/

   int brella = map(red_light, 25, 700, 120, 50);

   int distance = map(photoVal, 300, 900, 0, 99);

   int distancetotravel = currentdistance - distance;

    long forwardStartTime;

    long backwardStartTime;

 if(buttonVal == LOW) {

/*************************************************************

    [ 3 ] driving outputs

*************************************************************/

   umbrellaMotor.write(brella);

   // tell the linear actuator where to go

   // while distance to travel is positive you'll extend for a cetain amount of time

   // once you have extended/retract then turn the motor off digital write to low

   if (250 < photoVal) {

     forwardStartTime = millis();

     Serial.println(" MOVING FORWARD");

     digitalWrite(LINEARACTUATORA, HIGH);

     digitalWrite(LINEARACTUATORB, LOW);

   }

     else {

     backwardStartTime = millis();

     Serial.println(" MOVING BACKWARD");

     digitalWrite(LINEARACTUATORA, LOW);

     digitalWrite(LINEARACTUATORB, HIGH);

   }

 }

  if (buttonVal == HIGH) {

   if (300 < red_light) {

     forwardStartTime = millis();

     Serial.println(" MOVING FORWARD (skip)");

     digitalWrite(LINEARACTUATORA, HIGH);

     digitalWrite(LINEARACTUATORB, LOW);

   } 

     else {

     backwardStartTime = millis();

     Serial.println(" MOVING BACKWARD (skip)");

     digitalWrite(LINEARACTUATORA, LOW);

     digitalWrite(LINEARACTUATORB, HIGH);

   }

 }

  // figure out linear actuator distance

 long currTime = millis();

 long deltaForwardTime = currTime - forwardStartTime;

 long deltaBackwardTime = currTime - backwardStartTime;

 if(deltaForwardTime > 6400) {

   // we are at full distance

   distance = deltaForwardTime - deltaBackwardTime;

 }

/*************************************************************

    [ 4 ] reporting information back to the user

*************************************************************/

 if (millis() >= nexttimetorun) {

   long inputvalue = (red_light * 99) / 5000;

   long photoprint = ((long)photoVal * 99) / 800;

   long brellaprint = ((long)brella * 99) / 180;

   Serial.print("red_light: ");

   Serial.print(red_light);

   Serial.print(", photoVal: ");

   Serial.print(photoVal);

   Serial.print(", distance: ");

   Serial.println(distance);

   screen.clear();

   screen.home();

   screen.print("i: ");

   screen.print(inputvalue);

   screen.setCursor(5, 0);

   screen.print("m: ");

   screen.print(brellaprint);

   screen.setCursor(8, 4);

   screen.print(photoprint);

   screen.setCursor(12, 5);

   screen.print("o: ");

   screen.print(distance);

   nexttimetorun = millis() + HALFSECONDWAIT;

 }

}