LightClockV2 - A Motivation for Teaching Scalable Digital Hardware Design

Learning embedded design can be achieved with simple standard applications and microcontrollers but to spark interest in the topic, to pursue digital hardware design, motivation of students is a key factor demanding new approaches. One of which is presented in this paper as the LightClockV2, a fancy LED-based visualization gadget, built from 60 RGB color LEDs mounted on a circular PCB board to generate radial light beams. For focusing beams, we used laser pointer lenses which are mounted and adjusted in 3D printed holders. A main challenge of the project was the generation of 180 individually controllable pulse width modulation (PWM) signals. Characteristics as a 100 kHz PWM frequency, expandability for other visualization applications and a full single chip solution tighten the project requirements. In an implementation perspective a FPGA based solution efficiently provides an appropriate computational unit (finite state machine) generating light patterns, and 180 PWM peripheral modules. However, the FPGA implementation is a powerful and high-performance realization of this application and faces significant advantages in contrast to a classical microcontroller-based solution.