Microcontroller-driven gray scale plasma receiver

• Published in: Journal of microcomputer applications Vol. 18; no. 1; pp. 55 - 64
• Main Authors: Kaur, D., Velayudhan, B.K.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 1995; Academic Press
• Subjects: Applied sciences; Display; Electronics; Exact sciences and technology; Input output; Gray scale; Color display; Chip; Microcontroller
• ISSN: 0745-7138; 1096-374X
• DOI: 10.1016/S0745-7138(95)80022-0

Plasma display panels, or PDPs, are widely used in industry. Special-purpose switches called rotary pulse generators (RPG) are used to control the various parameters of a picture on a plasma display panel: such as color, contrast, A/D rail and dot clock, which generate two different pulse patterns. When any control parameter needs to be increased or decreased, the corresponding RPG is rotated in a clockwise or anticlockwise direction, resulting in the generation of two different kinds of patterns of pulses on the two channels. The width of pulses is typically 8 ms and the time difference between the two pulses is 3 ms. In this paper, a cost-effective technique to replace these switches using the MC68HC11E9 microcontroller is presented.
The MC68HC11E9 is an advanced eight-bit microcontroller (MCU) with highly sophisticated on-chip peripheral capabilities. The input capture (IC) and output compare (OC) features of the MCU are used for the control logic. The control circuitry consists of an input block, MCU and an output selection block. The input block has debounced switches for each of the control parameters. A logic ‘high’ is detected on one of the IC lines, whenever the related switch is pressed, which results in the generation of a unique pulse pattern on the OC lines. The paper presents the hardware interface and the control software developed for MC68HC11E9 to implement the plasma display control.