Double Transducer: Light to Distance   (Group 1)

Final images

Detail photos

Final project movies

Devin's Final Double Transducer Video. Shows the system working normally and then shows the system working with the skip the middle button.

Narrative description

Everything is powered by 5 volts from the flat black board and through the flat white rectangle. A small, round object with two legs and a squiggly line in the middle reads brightness and tells a flat black board. Flat black board tells yellow clear heat pad how bright, heat up more when bright, and heat less when dark. The little orange bulb wrapped by the heat pad tells the black board how hot the heat pad is. Blackboard tells the small blue motor to turn. Turn and push forward when hot, turn and pull backward when cold. All the numbers the blackboard sees show up on the screen.

Progress images/videos

Discussion

When initially designing this double transistor, we took into account that the heating pad's heating process was not a problem, but the cooling process might be challenging. Indeed, during the practical implementation, the heating pad's inability to cool down quickly did cause some noise and required manual removal of the thermistor. Due to the limitations of the materials, we did not have any more electronic components that could quickly and efficiently cool down. If there were other options for components, it would make the movement smoother.

These electronic components and connections are less refined than I expected, and they are subject to more interference factors. Removing these interference factors and making the entire process smoother and more accurate is also a major undertaking. Making smooth electrical appliances is not an easy task.

Functional block diagram and electrical schematic

Code

Group 1 Double Transducer Project by Devin and Leaf

The code reads all the input values and drives output based on the input values in a loop, then displays all the values on an LCD Display

  Arduino pin | role  |  description

  -------------------------------------

  A0            input    Photoresistor

  A1            input    Thermistor

  3             input    Heat Pad

  5             output   Servo Motor

  8             output   Tactile Switch Button

SDA & SCL       output   LCD Display

#include <Wire.h> // Enables I2C communication

#include <Servo.h> // Library for controlling servo motors

#include <LiquidCrystal_I2C.h> // Library for I2C LCD display

LiquidCrystal_I2C screen(0x27, 16, 2); // Initialize LCD at I2C address 0x27, 16 columns x 2 rows

Servo gaugeMotor; // Create servo motor object

// Input and output variables

int photoVal, tempVal, buttonState;

int heatOutput, motorPosSkip, motorPos;

int brightnessPct, tempPct, heatPct, motorPct;

unsigned long quarterTimer = 0; // Timer for LCD refresh

// Pin configuration and initializations

void setup() {

  pinMode(3, OUTPUT);

  gaugeMotor.attach(5);

  Wire.begin();

  screen.init();

  screen.backlight();

  Serial.begin(9600); // Start serial communication for debugging

}

// Main loop: read sensors, compute outputs, update display, and control devices

void loop() {

  readInputs();

  driveOutputs();

  lcdDisplay();

  skipTheMiddle();

  reportBack();

  delay(100);

}

// Reads sensor and button inputs

void readInputs(){

  buttonState = digitalRead(8);

  photoVal = analogRead(A0);

  tempVal = analogRead(A1);

}

// Maps sensor values to output control signals for heat and motor

void driveOutputs(){

  heatOutput = map(brightnessPct, 0, 99, 0, 255);

  motorPosSkip = map(photoVal, 0, 1023, 0, 90);

  motorPos = map(tempVal, 400, 900, 10, 170);

}

// Sends sensor data to Serial Monitor for debugging

void reportBack(){

  Serial.print("photoVal = ");

  Serial.print(photoVal);

  Serial.print(", tempVal = ");

  Serial.print(tempVal);

  Serial.print(", buttonVal = ");

  Serial.println(buttonState);

}

// Converts raw sensor values to percentages and displays them on the LCD

void lcdDisplay(){

  brightnessPct = map(photoVal, 200, 1023, 0, 99);

  tempPct       = map(tempVal, 500, 900, 0, 99);

  heatPct       = map(heatOutput, 0, 255, 0, 99);

  motorPct      = map(motorPos, 10, 170, 0, 99);

// Display brightness (i), heat output (m), temperature (#), motor rotation (o)

  if((millis()-quarterTimer) >= 250){ // Refresh LCD every 250ms

      screen.clear(); // clears numbers from screen

      screen.home();  // Set cursor to top-left

      screen.print("i:");

      screen.print(brightnessPct);

      screen.setCursor(6, 0);

      screen.print("m:");

      screen.print(heatPct);

      screen.setCursor(8, 1);

      screen.print(tempPct);

      screen.setCursor(12, 1);

      screen.print("o:");

      screen.print(motorPct);

      quarterTimer = millis();  // Reset timer

  }

}

//  Skip the middle step when button is held down

void skipTheMiddle(){

  if (buttonState == HIGH) {  // While button is pressed

    gaugeMotor.write(motorPosSkip); // Move servo based on brightness

    } else {

    //heatpad

    digitalWrite(3, heatOutput);  // Activate heat pad with PWM

    gaugeMotor.write(motorPos); // Move servo based on temperature

  }

}