This is an electronic 3-D LEGO sprite of Mega Man, made using similar technology as my Super Mario Dry Bones sprite from summer 2015. Inside this model I’ve got a small circuit built with an Atmel ATmega328P programmed with Arduino to play polyphonic music. Unlike the Dry Bones sprite, however, I made improvements with the LED-music synchronization. The Dry Bones sprite used a flickering LED for an eye, but since then I’ve figured out to multiplex LEDs with the same output pins of the PWM audio signals. In layman’s terms, I’ve discovered a way to have the audio signals simultaneously control LEDs, by having the circuits split off in different routes from a common pin on the ATmega328. Thus, the three LEDs on Mega Man’s Mega Buster blink in sync with each audio pulse, which is split off in three channels. As you can see in the demonstration video, the three lights blink at different times and overlap according to the audio signals. The three LEDs are connected to individual pins on the ATmega328, and not connected together in a single parallel circuit.

One of the major problems I ran into with the previous Dry Bones sprite (as well as the DL-44 Blaster) was having wires and components come loose from the circuit board. This is because I dislike permanently soldering certain components, so that I can make replacements or repairs if necessary, but by doing so, I risk the possibility of pieces coming loose from shoddy header pins. In this model, I’ve soldered male header pins on the circuit board instead of female ones, and this made sturdy connections with female jumper wires. This means if an LED burns out or if the speaker gets damaged, I can just disconnect the wires and install new ones (kind of like a car stereo).

The design for this sprite was pretty straightforward, and was initially conceptualized in LEGO Digital Designer, similar to the previous blinking sprites I’ve built. The inner circuit is powered by three AAA batteries, and for sound I’ve used a small 8 Ohm speaker from Radio Shack. The speaker is pushed up against a Technic plate with grille tiles on the outside (the sprite’s right eye), in order to allow the sound to escape. To activate, a small tactile button is suspended atop the head, and when pressed, it plays the “Game Start” theme music from the original Mega Man series. I constructed this project especially for a birthday/Christmas gift of one of my friends, as he’s always been a Mega Man fan since childhood!