Hardware Reference
In-Depth Information
The Pi Prompter
You could spend a small fortune on a teleprompter; however, it is quite easy to make one
yourself using nothing more than the Raspberry Pi, a sheet of glass and a few ixings. A
rather simpliied diagram of what is needed is shown in Figure 4-1.
Figure 4-1:
he Pi Prompter.
In somewhat of a reverse of the normal procedure, I will discuss the practicalities of this
setup last, after you have the Pi producing something to display.
In essence the requirements sound simple: You need to produce large words scrolling slowly and
smoothly up the screen. You need to be able to control the speed of the scroll, and pause it if
required. he inal twist is that you have to include an option to turn the words into mirror writ-
ing to compensate for any relection from the glass, if you have that sort of a physical setup.
So here is an outline of what you need to do: Read words from a ile, show them in a window
in large type and scroll them up. hen if you think about it a bit more in-depth, you need to
make sure that the words can it on one line without overlowing it and breaking in the
middle of a word. his is not quite as easy as you might think.
Like all projects, you don't tackle this whole task head on all at once; instead, you get bits of
it going irst and build up what you want to do slowly. hat is what development is all about.
So tackle this in a number of stages.
What You Need to Do
First of, you need to understand how graphics are shown on a screen. Basically what you see
on a TV monitor is a visual representation of an area of computer memory. Each pixel is a
