Week 7- Journal

Ideation

Tell us about your assignment's idea for this week. Why do you care about this idea? What inspired you? (Please include images or links to sources of inspiration)

For this week’s assignment, I built a Smart Desk Motivator: a small gadget with an RGB mood light and an LCD that shows motivational quotes at the press of a button. The goal is to make studying or working at my desk more positive and enjoyable.

I chose this idea because I often lose focus during long hours at my desk, and a short uplifting message or a calming light effect can help reset my mindset. This makes the device both practical and fun.

My inspiration came from projects like Arduino Random with LCD and RGB LED Mood Light. I wanted to combine these ideas into something personal and useful for my daily routine.

Resources of Inspiration:

RGB with Arduino

RGB Instructables

Random Diffuse Code

Tool Chain

Which software/machines/materials did you use in the assignment? Why?

Software/Machines/Materials Used

For this assignment, I used Tinkercad to design and simulate my circuit before physical implementation.

Why I Used It

Tinkercad allows me to test the connections, components, and logic virtually, which helps in identifying errors early and saves time and materials before moving to real hardware.

Software/Machines/Materials Used
For this assignment, I used the Arduino IDE to write, compile, and upload the code that controls the smart safe system.

Why I Used It
The Arduino IDE provides an easy-to-use platform for coding in Arduino C, testing logic, and directly uploading programs to the Arduino UNO board. It also includes a built-in serial monitor that helps with debugging and verifying communication between components, which makes it ideal for developing and refining embedded system projects like this one.

LCD (16*2) with I2C

RGB LED

Resistor

Materials:

breadboard
Arduino UNO
Arduino Cable
Jumper wires
RGB LED
220 Ohm Resistor
LCD with I2C
Cardboard
Push Buttons
9V Power Adaptor
Buzzer
Ultrasonic Sensor

Why I Used Them

Breadboard, jumper wires, switch: for easy circuit assembly and testing.
9V power adaptor: to safely run all components.

Arduino Uno = brain

Buzzer – to generate sound (alerts/melody when the distance condition is met).

Resistors = protect/signal conditioning

Breadboard & Wires = connection platform

RGB LED: for lighting at night

Cardboard: for holding the mechanical part

LCD: for displaying the Quotes

Push Button: Dynamic Input for the LCD and RGB LED

Function of the Ultrasonic Sensor

Measures distance by sending ultrasonic pulses and receiving the echo.
Acts as a proximity detector (triggers buzzer when an object < 20 cm).

Design/Preparation Process

Explain the design and/or preparation process of your assignment. How did you use the tool or software to design and/or prepare your assignment before fabrication/implementation?

TinkerCAD Circuit Video

First RGB LED Design on TinkerCAD:

Dynamic Inputs:

2 Dynamic Push Buttons

Ultrasonic Sensor

Output (Action Components):

LCD to illustrate the random Quotes

RGB to show Red - Blue - Green sequence

Buzzer to make Music

Design of the RGB LED:

RGB LED Design

Connected red, green, and blue pins of the RGB LED to Arduino pins 7, 6, and 5 through resistors 330 Ohm.
Common cathode connected to GND.
Added a push button on pin 4 using INPUT_PULLUP to toggle the RGB light on/off.
Programmed cycling of colors (red → blue → green) with if conditions and delay().

LCD Design

Used a 16x2 I2C LCD for easier wiring.
Connected SDA → D18 and SCL → D19, with VCC → 9V and GND → GND.
Added a button on pin 3 to toggle LCD quotes on/off.
Programmed the LCD with the LiquidCrystal_I2C library to display random quotes using the random() function.

Buzzer and Ultrasonic Sensor Design

Ultrasonic Sensor

Used an HC-SR04 ultrasonic sensor for non-contact distance measurement.
Connected Trig → pin 8 and Echo → pin 9, with VCC → 5V and GND → GND.
Programmed to calculate distance using pulseIn() and the sound speed formula.
Configured a threshold: if an object is closer than 20 cm, it triggers the buzzer melody.

Buzzer:

Used a passive buzzer connected with positive → pin 10 and negative → GND.
Programmed with the Arduino tone() function to play a simple melody.
Activated only when the ultrasonic sensor detects an object within range.
Provides audible feedback to enhance the system's interactivity.

Preparation with Software

Designed and tested the circuit in Tinkercad Circuits before implementation.
Verified pin connections, button logic, buzzer, ultrasonic sensor and LCD text alignment.
This reduced wiring errors and made the physical build easier.

Code:

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

// RGB

const int RGB_Red = 7;

const int RGB_Blue = 6;

const int RGB_Green = 5;

// Buttons

const int RGB_Button = 4;

const int LCD_Button = 3;

// Ultrasonic + Buzzer

const int trigPin = 8;

const int echoPin = 9;

const int buzzer = 10;

//RGB Button

bool isOn = false;

bool lastRGBButtonState = HIGH;

//LCD

LiquidCrystal_I2C lcd(0x27, 16, 2);

bool lastLCDButtonState = HIGH;

bool lcdOn = false;

int quoteIndex = 0;

//Quotes

String quotes[] = {

"Keep moving!", "Believe in yourself", "Dream big.", "Stay positive!",

"Never give up.", "Enjoy your day", "Your blessings?", "Most imp Advice?",

"Love your family", "Commitment today?", "No perfectionism", "Start small now",

"Baby steps matter", "Be kind to yourself", "Your faults?", "Your day routine?",

"Grateful for today?", "What excites you?", "Let go of fears", "Smile at a stranger",

"Write 3 wins today", "What inspires you?", "Focus on progress", "What drains energy?",

"Define success now", "Write 1 big goal", "Who supports you?", "Acts of kindness?",

"Your core values?", "What to forgive?", "Step outside comfort", "Name 3 strengths",

"Your happy memory?", "Who to thank today?", "1 word for today?"

};

const int numQuotes = sizeof(quotes) / sizeof(quotes[0]);

// Simple melody (notes + durations)

int melody[] = {262, 294, 330, 349, 392, 440, 494, 523}; // C D E F G A B C

int noteDurations[] = {4, 4, 4, 4, 4, 4, 4, 4}; // quarter notes

long getDistance() {

digitalWrite(trigPin, LOW);

delayMicroseconds(2);

digitalWrite(trigPin, HIGH);

delayMicroseconds(10);

digitalWrite(trigPin, LOW);

long duration = pulseIn(echoPin, HIGH);

return duration * 0.034 / 2; // cm

}

void playMelody() {

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

int noteDuration = 1000 / noteDurations[i];

tone(buzzer, melody[i], noteDuration);

delay(noteDuration * 1.3);

noTone(buzzer);

}

void setup()

{

pinMode(RGB_Red, OUTPUT);

pinMode(RGB_Green, OUTPUT);

pinMode(RGB_Blue, OUTPUT);

pinMode(RGB_Button, INPUT_PULLUP);

pinMode(LCD_Button, INPUT_PULLUP);

pinMode(trigPin, OUTPUT);

pinMode(echoPin, INPUT);

pinMode(buzzer, OUTPUT);

randomSeed(analogRead(A0));

lcd.init();

lcd.backlight();

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Press button :)");

}

void loop()

{

//RGB Button

bool RGBbuttonState = digitalRead(RGB_Button);

if (lastRGBButtonState == HIGH && RGBbuttonState == LOW) {

isOn = !isOn;

delay(200);

}

lastRGBButtonState = RGBbuttonState;

//LCD Button

bool LCDbuttonState = digitalRead(LCD_Button);

if (lastLCDButtonState == HIGH && LCDbuttonState == LOW) {

lcdOn = !lcdOn;

if (lcdOn) {

quoteIndex = random(numQuotes);

lcd.clear();

String quote = quotes[quoteIndex];

if (quote.length() < 16){

lcd.setCursor(0, 0);

lcd.print("Hello my Girl,");

lcd.setCursor(0, 1);

lcd.print(quote.substring(0, min(16, quote.length())));

} else {

lcd.setCursor(0, 0);

lcd.print(quote.substring(0, 16));

lcd.setCursor(0, 1);

lcd.print(quote.substring(16, min(32, quote.length())));

}

} else {

lcd.clear();

lcd.print("LCD Off");

lcdOn = false;

}

delay(200);

}

lastLCDButtonState = LCDbuttonState;

// RGB Logic

if (isOn){

digitalWrite(RGB_Red, HIGH); delay(1000); digitalWrite(RGB_Red, LOW); if (!isOn) return;

digitalWrite(RGB_Blue, HIGH); delay(1000); digitalWrite(RGB_Blue, LOW); if (!isOn) return;

digitalWrite(RGB_Green, HIGH); delay(1000); digitalWrite(RGB_Green, LOW); if (!isOn) return;

} else {

digitalWrite(RGB_Red, LOW);

digitalWrite(RGB_Blue, LOW);

digitalWrite(RGB_Green, LOW);

}

// Ultrasonic + Buzzer

long distance = getDistance();

if (distance > 0 && distance < 20) { // threshold = 20cm

playMelody();

}

Development/Implementation Process

Explain the development/implementation process of your assignment. How did you use the machine/tool to manufacture or implement the design of your assignment?

Video For the Circuit Working:

FlowChart

Implementation Steps

RGB LED

Red pin → Arduino pin 7 (through ~220Ω resistor).
Green pin → Arduino pin 5 (through resistor).
Blue pin → Arduino pin 6 (through resistor).
Common cathode → GND.

Buttons

Button 1 (RGB control) → Arduino pin 4, other side → GND.
Button 2 (LCD control) → Arduino pin 3, other side → GND
Use Arduino’s INPUT_PULLUP → no external resistors needed.

LCD (I2C)

VCC → Arduino 5V.
GND → Arduino GND.
SDA → Arduino D18(SDA).
SCL → Arduino D19 (SCL).

Buzzer

Positive terminal → Arduino pin 10.
Negative terminal → GND.
Used with tone() function to play melodies when an object is detected.

Ultrasonic Sensor (HC-SR04)

VCC → Arduino 5V.
GND → Arduino GND.
Trig Pin → Arduino pin 8.
Echo Pin → Arduino pin 9.
Measures distance by sending ultrasonic pulses and detecting their echo.

Power & Testing

Power circuit via Arduino USB or external 9V adapter.
Ensure all grounds are connected together.
Upload the Arduino code.

Behavior after Upload

On startup, LCD shows: “Press button :)”.
RGB Button → Cycles LED colors: Red → Blue → Green.
LCD Button → Randomly displays a motivational quote, or “LCD Off” when toggled.
Ultrasonic Sensor + Buzzer → When an object is detected within 20 cm, the buzzer plays a short melody.
RGB LED, LCD, and Ultrasonic+Buzzer operate independently, each controlled by their own logic.

Code:

Community of Learning

Did you ask for feedback? What are the ideas that others have contributed or suggested? What was someone else’s idea that you built upon? How did you help your peers? How did your peers help you?

The Issue

The bug was that the first line started at index 16, skipping the first 16 characters of the quote. That meant nothing (or “random” characters) appeared, so the LCD didn’t show the expected text. I shared my code and asked why the LCD wasn’t showing quotes correctly.

Solution:

-The key suggestion was that the substring should start at 0 for the first line, not 16.
-I built upon the suggestion to fix the substring indices, improving my LCD printing logic to split quotes into two lines properly.
- By sharing my detailed code, I contributed to the group’s understanding of how substring indexing works in Arduino and helped highlight a common mistake that others can avoid.
- They spotted the indexing mistake and explained why it caused the LCD to skip the first characters, providing a corrected version of the code.

Issue:

Solution:

Overcoming Challenges

When you got stuck, what/who did you turn to? At what point did you have to pause to research or learn more before moving on? What are some mistakes, pitfalls, or challenges that others can avoid if they were doing this assignment?

Issue

The push button used had 4 legs.
I initially connected the two legs next to each other, which caused the button not to work.
Even though I set the pin mode as INPUT_PULLUP, the circuit didn’t respond correctly.

Solution

Discovered that the correct way was to connect the diagonal legs of the push button.
Removed the external resistor since INPUT_PULLUP already handles it internally.
After rewiring, the push button worked properly.

How I Found the Solution

Sources: Trial 1, Tutorial

Researched online tutorials and maker forums about push-button wiring.
Discovered the correct method is connecting the diagonal legs.
Learned that INPUT_PULLUP removes the need for an external resistor.
Rewired and tested the circuit → push button worked properly.

Issue

When the push button was clicked to turn off the RGB, the LED cycle didn’t stop.
The lights continued running even though the button was pressed.
This was not a wiring problem but a logic issue in the code.

Solution

Added the line if (!isOn) return; inside the RGB sequence.
This ensured that when the button is pressed again, the RGB loop stops immediately.
Now the LED responds correctly to the button state (ON/OFF).

Final Project

How can you use the skills and knowledge that you've acquired this week in your final project?

This week, I learned how to connect and program an LCD with I2C and how to display random motivational quotes on it. This skill directly supports my final project because the random quote generator displayed on the LCD is a complete feature of the device. By mastering the wiring of the LCD and the logic behind generating and displaying random text, I can now integrate this function into my final prototype. It adds both interaction and motivation to the project, making it not only technically functional but also meaningful for users.

WOW!

What is the coolest thing that you've learned this week? What is something that you will never forget from this week?

This week, aside from the main assignment, I started experimenting with Processing to learn how we can use it to create visuals for a game on the laptop. I also tried out the Simon Game, and after many attempts, I managed to score 9 points! Through this, I learned the importance of correctly connecting the Arduino UNO, paying attention to the ports, and then uploading the Processing code so that everything works together smoothly. It was a fun way to combine both hardware and software to bring an interactive game to life.

Weekly Digest [OPTIONAL]

Tell us about any other cool things that you've made this week: in the Hands-on activity, tutorial examples, exercises, or any other cool mini-project that you tried out aside from the assignment.

Assignment Design Files

RGB + LCD + Buzzer and Ultrasonic Sensor on TinkerCAD

Arduino (.ino) Code

Page updated

Report abuse

Week 7- Journal

Ideation

Tell us about your assignment's idea for this week. Why do you care about this idea? What inspired you? (Please include images or links to sources of inspiration)

Tool Chain

Which software/machines/materials did you use in the assignment? Why?

Software/Machines/Materials Used

Why I Used It

Why I Used Them

Function of the Ultrasonic Sensor

Design/Preparation Process

Explain the design and/or preparation process of your assignment. How did you use the tool or software to design and/or prepare your assignment before fabrication/implementation?

TinkerCAD Circuit Video

First RGB LED Design on TinkerCAD:

Design of the RGB LED:

RGB LED Design

LCD Design

Buzzer and Ultrasonic Sensor Design

Ultrasonic Sensor

Buzzer:

Preparation with Software

Code:

Development/Implementation Process

Explain the development/implementation process of your assignment. How did you use the machine/tool to manufacture or implement the design of your assignment?

Video For the Circuit Working:

FlowChart

Implementation Steps

Buttons

LCD (I2C)

Buzzer

Ultrasonic Sensor (HC-SR04)

Power & Testing

Behavior after Upload

Code:

Community of Learning

Did you ask for feedback? What are the ideas that others have contributed or suggested? What was someone else’s idea that you built upon? How did you help your peers? How did your peers help you?

The Issue

Solution:

Issue:

Solution:

Overcoming Challenges

When you got stuck, what/who did you turn to? At what point did you have to pause to research or learn more before moving on? What are some mistakes, pitfalls, or challenges that others can avoid if they were doing this assignment?

Issue

Issue

Solution

Final Project

How can you use the skills and knowledge that you've acquired this week in your final project?

WOW!

What is the coolest thing that you've learned this week? What is something that you will never forget from this week?

Weekly Digest [OPTIONAL]

Tell us about any other cool things that you've made this week: in the Hands-on activity, tutorial examples, exercises, or any other cool mini-project that you tried out aside from the assignment.

Assignment Design Files

Social Media