Double Transducer: Light to Distance

Final images

Detail photos

Final project movies

Carmyn's double transducer board turned on and running its code. The photoresistor value is changed to its extremes by either covering it with a hand or holding a flashlight over it. In response, the incandescent lightbulb, which is blocked by the soldered breadboard in the first part of the video, changes its heat output. The heat output is read by the thermistor attached to the said soldered breadboard. The thermistor value is then mapped to a position for the linear actuator to go to. The LCD screen in the bottom right displays the input and output values of each of the steps. 

In this board the linear actuator moves in and out quickly while overall slowly making its way to its desired position. There are three potential solutions to this. The first is that there could be an issue with the mapping of the thermistor values to the input values of the actuator. The second is that we could have added an epsilon value to the thermistor reading such that there is a slightly wider range of input values corresponding to the movement to make it waver less. The third is that we could have taken an average value of the last however many (for example 5) readings of the thermistor to send to the actuator so once again it has less jagged movements. 

Gus's double transducer board turned on and running its code. The circuit works the exact same way as the previous caption. The difference with this board is for some reason the linear actuator moves much smoother, but it does not seem to respond to the changing values of the previous steps in the circuit. This is particularly strange because we should have the exact same code, but I believe the differences may be due to a change in the pin mapping that one of us did and the other did not. 

Narrative description

Progress images

Day 6 progress: (above two images)

For our last work day, we built both projects and affixed them onto the cardboard. We also added some fun highlights, letting our project tell the story of how Punxsutawney Phil can see the future (with some lag.)

Discussion

Functional block diagram and electrical schematic

Code

/*

 Project 1 - Double Transducer: Light to Distance

 Carmyn Talento and Gus Gamble

 The double transducer project gives us an assigned domain for a starting input and ending output,

 and our goal is to choose a third domain as a middle step. Our given starting input is light brightness,

 and our final output is linear position, and we chose our middle domain to be heat. All of our steps must

 be continuously changing the next step. To accomplish this, we have a photoresistor reading the light input,

 followed by an incandescent light bulb producing heat, followed by a thermistor reading the temperature,

 followed by a linear actuator extending and retracting. Once completed, we will attach our project into a

 larger line of projects where our final output is the starting input to the next group's project.

Sources:

https://www.firgelliauto.com/blogs/tutorials/how-do-you-control-a-linear-actuator-with-an-arduino 

https://arduinogetstarted.com/tutorials/arduino-actuator 

   Pin mapping:

   Arduino pin | role  | details

   ------------------------------

   A0             input   photoresistor

   A3             input   thermistor

   9             output   linear actuator motor 1

   10            output   linear actuator motor 2

   11            output   incandescent light bulb

*/

//insert library and set up values for screen display

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C screen(0x27, 16, 2);

int x = 123;

//set pins for the significant components

const int PHOTOPIN = A0; //photoresistor

const int THERMOPIN = A3; //thermistor

const int MOTORPIN1 = 9; //actuator motor 1

const int MOTORPIN2 = 10; //actuator motor 2

const int INCANPIN = 11; //incandescent bulb

int currPos = 50; //keeps track of the actuator's current position

//set up process

void setup() {

 //pin set up

 pinMode(PHOTOPIN, INPUT); //photoresistor

 pinMode(THERMOPIN, INPUT); //thermistor

 pinMode(MOTORPIN1, OUTPUT); //motor 1 in linear actuator

 pinMode(MOTORPIN2, OUTPUT); //motor 2 in linear actuator

 pinMode(INCANPIN, OUTPUT); //incandescent bulb

 //screen set up

 screen.init();

 screen.backlight();

 screen.home();

 //retract linear actuator before starting

 digitalWrite(MOTORPIN1, LOW);

 digitalWrite(MOTORPIN2, HIGH);

 //turn on serial library

 Serial.begin(9600);

}

//control loop

void loop() {

//saving information to variables for the values of each step

 int photoVal = map(analogRead(PHOTOPIN), 50, 950, 0, 99); //step 1: photoresistor value

 int incanVal = map(photoVal, 0, 99, 0, 1023); //step 2: incendescent bulb value

 int thermoVal = map(analogRead(THERMOPIN), 50, 950, 0, 99); //step 3: thermistor value

 int actVal = map(thermoVal, 0, 99, 100, 1000); //step 4: linear actuator value

//display values on LCD screen on scale of 0 to 99 for all 4 steps

 //write to LCD- photoVal, incanVal, thermoVal, actVal

 screen.print("i:");

 screen.print(photoVal);

 screen.setCursor(6,0);

 screen.print("m:");

 screen.print(map(incanVal, 0, 1023, 0, 99));

 screen.setCursor(8, 1);

 screen.print(thermoVal);

 screen.setCursor(12, 1);

 screen.print("o:");

 screen.print(map(actVal, 0, 128, 0, 99));

//final output, step 4

 analogWrite(INCANPIN, map(photoVal, 0, 99, 0, 1023));

  //extend linear actuator

 if (currPos > thermoVal){ //add an epsilon value to the thermoVal to smooth out the movement

   digitalWrite(MOTORPIN1, HIGH);

   digitalWrite(MOTORPIN2, LOW);

   delay(actVal);

   digitalWrite(MOTORPIN1, LOW);

   digitalWrite(MOTORPIN2, LOW);

   currPos = currPos + actVal;

 } 

 //retract linear actuator

 else if (currPos < thermoVal){ //add an epsilon value to the thermoVal to smooth out the movement

   digitalWrite(MOTORPIN1, LOW);

   digitalWrite(MOTORPIN2, HIGH);

   delay(actVal);

   digitalWrite(MOTORPIN1, LOW);

   digitalWrite(MOTORPIN2, LOW);

   currPos = currPos - actVal;

 } 

 //don't move linear actuator

 else if (currPos == thermoVal){ //add an epsilon value to the thermoVal to smooth out the movement

   digitalWrite(MOTORPIN1, LOW);

   digitalWrite(MOTORPIN2, LOW);

   delay(actVal);   

 }

//check values and reset screen

 //check values in serial monitor

 Serial.print("thermoVal: ");

 Serial.print(thermoVal);

 Serial.print(", photoVal: ");

 Serial.print(photoVal);

 Serial.print(", incanVal: ");

 Serial.print(incanVal);

 Serial.print(", actVal: ");

 Serial.println(actVal);

 Serial.print(", currPos: ");

 Serial.print(currPos);

 // delay and clear screen to reset and not overwhelm screen

 delay(100);

 screen.clear();

}