Automatic light intensity control for a POV technology based display

One of the most important aspects of promoting a product is to well advertise it. The big advances in technology provide many modes to present the information. Some of the technologies which can provide a low cost, effective and impressive set-up to advertise a product are LED Persistence of Vision (POV) Displays. Current project has in focus to build a POV Display intended to be used for multiple applications: displaying a text message, creating a luminous clock and exposing hologram animations. The device consists of two main parts, each one being driven by its own microcontroller: a static part and a rotating arm (propeller). The fixed part is designed to control a DC motor, which rotates the propeller at different speeds. The mobile arm containing a LED strip, a Bluetooth module and two sensors for luminosity aims to display images and control the light intensity of LEDs. One feedback controller is set up for each of above mentioned project components. In order to control the DC motor speed, a Proportional-Integrative (PI) controller was designed. To adapt LED strip intensity at environment light, two approaches were proposed: conventional PI controller and Fuzzy logic controller. The controllers are tested in Simulink and after that implemented on microcontroller. Their benefits are emphasized. The user can change displayed images using an Android application which communicates with designed system via Bluetooth.