Návrh řídicí jednotky pro sférický zobrazovač

Abstract

This bachelor’s thesis deals with the design and implementation of a spherical POV (Persistence of Vision) display based on a rotating 65 cm hoop equipped with 240 RGB LEDs controlled by a Raspberry Pi Pico 2W microcontroller. The theoretical part describes the physiology of the human eye and the Persistence of Vision phenomenon, from which concrete requirements for refresh rate, brightness, and synchronization of a rotational display are derived. The practical part documents the iterative development of the control electronics — from verifying the logic of 74HC595 shift registers on a breadboard, through implementation on an Arduino Nano, to the final migration to the Raspberry Pi Pico 2W platform. The resulting control unit uses two independent hardware SPI interfaces clocked at 10 MHz to drive 30 LED modules in parallel, transferring one 360-bit image column in 36 μs. At an operating speed of 1020 RPM, the device achieves a refresh rate of 17 Hz and a resolution of 180 × 120 pixels. Via its integrated Wi-Fi module, the unit hosts a web interface for wireless content upload during operation, which in the second development iteration was complemented by a standalone desktop application operating in access-point mode.