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AN ELECTRONIC LITESHOW DISPLAY

Part 2: Controlling the Lights with Software

by James Antonakos

Start ý Recap ý Software Initialization ý Building a Bit Pattern ý Outputting Data to the Display ý Scrolling the Display Pattern ý Handling Network Messages ý Other Uses ý Sources and PDF

BUILDING A BIT PATTERN

Before a network or canned message can begin scrolling across the LiteShow display, a bitmap containing the binary patterns used to form all the display characters must be created for it. Each character is contained in a 5 ý 7 array of on/off values used to control the lamps. The patterns for the letters A, B, and C are shown in Listing 3 to illustrate the organization.

To build the bitmap, each character from a new message is used to locate its corresponding 5 ý 7 pattern, and the pattern is copied into the bitmap. Spacing between character patterns in the bitmap is accomplished by skipping one column of bits between patterns. Thus, a message containing 20 characters results in a bitmap containing 120 columns of data. Extra blank columns are added to the end of the bitmap so that the display blanks from right to left as the message scrolls off the display.

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