Week 8 - 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)

The goal of this project was to design and implement a smart circuit that can be controlled wirelessly using Bluetooth communication between a phone/PC GUI and an Arduino UNO. The circuit integrates two action components:

A stepper motor (28BYJ-48 with ULN2003 driver)
An RGB LED

Through the GUI, commands are sent to the Arduino via Bluetooth. The Arduino interprets the incoming serial data and performs the corresponding action—either rotating the motor forward/backward or changing the LED color.

no source on inspiration, wanted to test my final project and was fun controlling it wirelessly

Tool Chain

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

For the design I used TinkerCAD.
Coding and uploading the code to the Arduino Uno was done using Arduino IDE
Arduino Bluetooth Control - Apps on Google Play to send characters to arduino from phone

Electrical components

Arduino UNO
28BYJ-48 stepper motor with ULN2003 driver board
RGB LED (common cathode)
Resistors (330Ω for LED protection)
HC-05 Bluetooth module
Breadboard and jumper wires
Android phone with Bluetooth terminal app (for GUI simulation)

Arduino UNO

HC-05

DC 9 Volt power supply

Jumper Wires

28BYJ-48 stepper motor with ULN2003 driver board

330 ohm resistors

Breadboard

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?

Circuit Diagram

sorry about the design couldn't find driver or stepper or hc-05

Connections:

Stepper Motor → Arduino pins 8, 10, 9, 11 (via ULN2003 driver)
RGB LED → Arduino pins 5 (Red), 6 (Green), 7 (Blue)
Bluetooth Module:
VCC → 5V
GND → GND
TX → RX (Pin 0)
RX → TX (Pin 1)

How It Works:

The Bluetooth GUI sends single-character commands (f, b, 1–6) to the Arduino.

The Arduino decodes the character:

f → motor rotates forward

b → motor rotates backward

1–6 → RGB LED lights up in different colors

The motor moves in small steps for controlled rotation, while the RGB LED displays selected colors.

the code:

Simulation of the circuit: (full electronics assembly)

WhatsApp Video 2025-09-23 at 3.06.37 AM.mp4

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?

When connected to the Bluetooth terminal app, sending commands successfully controlled the circuit:

Motor rotated forward/backward depending on commands.

RGB LED changed to six distinct colors.

The communication was reliable and real-time with minimal delay.

app used:
Arduino Bluetooth Control - Apps on Google Play

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?

I had a major challenge with the Bluetooth module. it wouldn't conenct and even if it did. it would only send 1 character then disconnect immediately.
I solved this issue by connecting it directly to a 5v adapter voltage source which caused it to be more stable

Final Project

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

controller the same motor I would be using in final proejct

WOW!

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

We had

Assignment Design Files

Full .ino project code

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