That’s the question [Kathy] asked when she built this LED matrix light pen project. It looks simple enough – a 64-LED matrix illuminates as the pen draws shapes. But how does the circuit ...

Note the 3D printed separator that goes on top of the LED matrix, and the laser-cut acrylic front panel that covers the diffuser. Most of the components go on the rearmost of the PCB stack ...

In addition to a bright front light, the helmet has a 7x11 dot-matrix, animated LED panel on its rear to signal turns and brakes to drivers — an upgrade from the static display of Lumo's ...