Lim Le Xi's Coding Projects
My name is Le Xi, and I am 12 years old. I started learning robotics with LEGO Mindstorms and block-based coding in Primary 4, where I enjoyed designing and building robots to automate daily tasks. Robotics inspired me to solve real-world problems and explore beyond block-based coding, which led me to learn Python. Using Python, I wrote programs to solve math problems without pen and paper. I also learned Pygame to create educational games where my friends could compete and challenge one another. I have documented my journey in robotics, coding, innovation, and STEM.
Bumper Car
I learned how to use LEGO Technic parts to design and build functional mechanical systems. By applying coding concepts such as conditionals (if-else) and integrating various sensors, I programmed my creations to respond dynamically to their environment. One example was a bumper car that automatically reverses when its front touch sensor detects a collision—mimicking real-world applications of obstacle detection used in autonomous vehicles and robotic systems to enhance safety and navigation.
Sushi Belt
I enjoy going to the restaurant for sushi and decided to recreate an automated one. Using the lego technic parts and a colour sensor, I created a sushi belt that is activated to move only when it detects the colour green. This reduces unnecessary motion and saves energy.
Distance Sensor Coin Dispenser
Inspired by arcade coin dispensers, I applied the design principles and coding skills I learned to build a distance-activated coin dispenser. The dispenser uses two ultrasonic sensors that detect my hand in a specific sequence within a defined distance threshold. When both sensors are triggered in order, the mechanism opens to release coins. This project demonstrates how sensor integration and conditional logic can create automated systems, similar to those used in vending machines .
Touch Activated Automated Rabbit Head
My younger siblings loved playing with their toy rabbit head, which spins when the wind hits it. They used to manually spin and stop it, which was fun but limited. To make it more interactive and engaging, I decided to create an automated version of the toy. In this upgraded version, the rabbit head starts spinning automatically as soon as the program runs. When the ultrasonic sensor detects someone nearby—such as a child approaching—the spinning stops, and the toy returns to its original position.
Touch Activated Lazy Susan
As someone who enjoys eating at restaurant—especially chinese restaurant, I recreated a lazy susan using LEGO Technic parts. It incorporates 1 touch sensor and ultrasonic sensor to make decisions about when and how to spin, based on when the touch sensor is activated and when the ultrasonic sensor detects something near it. This adds a layer of convenience and control that reflects how real-world rides use environment-sensitive automation.
Touch & Colour Activated Merry Go Round
As someone who enjoys exercising on a treadmill, I decided to recreate an automated treadmill using LEGO Technic parts. This miniature version functions similarly to a real treadmill—its speed is controlled by user input. With the use of a touch sensor, and coding concepts such as variables and if-else statements, the treadmill increases speed with each press—just like speed adjustments on a real gym machine.
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This project shows how to calculate the remainder when one number is divided by another. It’s a great way to practice using arithmetic and the modulo operator (%).
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In this project, I designed a program that checks if a number is even or odd using if-else statements. This project teaches me how to make decisions in code based on conditions.
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This game challenges you to decide if a number is prime by using if-else statements. It’s a fun way to reinforce the concept of prime numbers and divisibility in code.
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I organized a math competition among my friends, and one of the challenges involved calculating the factorial of a given number. I created a Python script that took a user input and calculated the factorial of the given number.
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In this project, I used a for loop to count the number of vowels and consonants in a given string. The loop iterates through each character in the string, checking if it is a vowel or consonant, and updates the counts accordingly.
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In this project, I created a number pyramid using nested for loops. The outer loop controls the number of rows, while the inner loop prints the numbers in each row. This project demonstrates how to use loops to create patterns and shapes in Python.
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In this project, I learned how to create a program that takes in a user input for a choice of word and prints the word diagonally in a square matrix using a nested for loop concept.
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In this project, I created a program that uses nested loops concept to build a classic math triangle known where each number is the sum of the two numbers above it.
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I have created a Python script named sum_of_my_even_numbers.py. It prompts me for a positive integer, and using a while loop, it calculates and displays the sum of all even numbers from 2 to the entered integer.
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In this project, I built a countdown timer that uses a while loop to count down from a starting number until it reaches 1. This is important because it shows me how to repeat an action until a condition is met.
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