Sheldon Maloff, a computer programmer, has always been a fan of Lego models and keeps building various layouts. So after winning a Lego T-intersection model in an online auction, he decided to combine it with an Arduino embedded microcontroller and developed an LED Traffic light as his DIY project. With the T-intersection as the centre of the layout, he used many other components like Lego bricks, LED lights, resistors, Arduino controller, etc.
He got started with collecting some LEDs for the traffic lights for which he utilized a strip of half-lit LED lights from his Christmas tree. In total, there were 10 LEDs including 4 green, 3 yellow and 3 red, each with a diameter of 3mm. After extracting these lamps from the tree and testing them, he prepared the headlight bricks and made sure that the LEDs fit into those bricks correctly. In the next step, he assembled the headlight bricks, plates and tiles and placed circular studs on top of them to denote the traffic lights.
Then with the help of a hot glue gun he injected some glue into the bricks to fit the LEDs inside them such that the anode remained on the top while the cathode stayed on the bottom. To make sure that the setup worked properly, he again tested the LEDs. Then for the soldering, he took a flexible 18-inch strand of wire with 0.25mm thickness, stripped it up to 2-inches with the help of tweezers and started wrapping it on the cathode part of the LEDs one by one. Similarly, he repeated the process to solder the anode wires.
Afterwards, he collected the grey bricks and threaded them into the bundle of wires to connect them to the headlight brick. This grey part denoted the traffic light pillars or lamp posts. Then he threaded a black heat shrink tube into the bundle of wires followed by a blue heat shrink tube into each of the strands. Then finally he stripped the end of the wires and soldered them to a male pin header.
In order to get the connectors fit through the surface, he cut a slot into the base so that all the electronic components could be concealed underneath the model. For the Arduino Nano, he prepared a circuit using female pin headers and mounted it on top of the microcontroller. He also prepared a dumpster to place the Arduino to ensure that it didn’t look out of place. Finally, he taped down all the wires on the surface. Then after some coding and programming, the project was tested with some mini figs and toy cars placed on the intersection. Power was supplied by a 9-volt battery which could keep the lights working for around 8 hours.
You can have a look at the details along with the coding at the link given below. This project can also be improvised and customized to a certain extent by utilizing the concept rendered by Sheldon. There is also a video posted on the internet where you can see the demonstration of this LED traffic light project with some realistic sound effects.
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