What started as a playful experiment with LEGO Technic grew, over the course of my studies, into a serious deep-dive into electronics, embedded systems, and the world of microcontrollers. With Arduino and classic electrical-engineering projects, I laid the groundwork for my love of tinkering — and out of that came the idea for a wall plotter that turns a simple JPG into real graffiti on the wall.
The early days — experimenting and learning
In my first study years I was fascinated by the world of microcontrollers. With Arduino I gathered my first experience, built simple circuits, and learned soldering and how to work with various sensors and actuators. It became clear fast that the road from prototype to working system takes not just craft but a deep understanding of the underlying electronics and software.
Deeper learnings in the project
1. Stepper motors: precise positioning is the heart of a wall plotter. Here I learned how stepper motors — with their 2,048 steps per revolution — move in small, exactly controlled increments. I developed my own stepper class, programming not just the forward and reverse sequences but also the math to calculate the steps needed to get from one point to the next. Understanding the subtleties of synchronizing both motors was decisive for achieving smooth motion.
2. Embedded systems: the project gave me the chance to immerse myself in embedded systems. From using the Raspberry Pi Pico — whose RP2040 chip is a flexible, low-cost alternative to other microcontrollers — to integrating every hardware component so each module worked together optimally. Writing firmware, understanding interrupts and timers, and meeting real-time requirements were among my biggest challenges and most exciting learning moments.
3. Synchronization: synchronizing the two stepper motors turned out to be one of the biggest hurdles. I had to learn how to control several processes simultaneously and respond to any deviations. With mathematical conversions and dynamic adjustments in the control logic, I made sure both motors always moved in harmony — essential for drawing precise lines on the wall.
4. Soldering and electronics: the hands-on work was just as big a part of the project. From the first touch of the iron to the final board assembly, every soldered component contributed to the stability and function of the system. Here I learned how important clean connections and a structured approach to circuit development are. Small soldering errors could cause unpredictable problems, so patience and precision were the top priority.
From digital image to urban art
The goal was clear: turn digital vector data into real graffiti on a wall. Using modern software tools I converted simple JPGs into scalable vector graphics, then converted those into G-code with Python. That G-code steers the wall plotter, sending precise commands to the motors and a servo mechanism — the latter raising and lowering the pen to draw lines.
Conclusion and outlook
The journey from a simple LEGO experiment to a fully functional wall plotter was an exciting ride full of practical experience and valuable learnings. I got to dive deep into stepper motors, embedded systems, and electronics, acquiring not just theoretical knowledge but mastering real challenges — whether synchronizing the motors or soldering the fine circuits. The project showed me that technology and creativity go hand in hand, and that from a small hobby and plenty of curiosity, an impressive piece of work can emerge. The experiences from this project have stayed with me in every technical undertaking since.
Every soldered joint, every synchronized motor movement, and every line of code taught me that the road to innovation often runs through many small but meaningful steps.