#43
Breadboard
Part 2: The
Navigator Buttons
by Joe Pardue
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Recap
Last month, we looked at the LCD part of the LCD
Navigator project. This month, we will look at the
Navigator part: the five momentary pushbuttons arrayed
■ FIGURE 1. LCD Navigator.
as a cross in Figure 1. These buttons can be used to
navigate a menu much like you would typically do
with a TV remote control five-button navigator as shown
in Figure 2. These buttons typically don’t have labels
since most folks intuitively know that they are up,
down, left, right, and select after just a few moments of
messing with them and watching what happens on a
TV menu.
We will first look at the hardware considerations for
using mechanical switches like these pushbuttons. Then,
we will learn to use the nav_button library that you can
find in avrtoolbox, buried fairly deeply in the folder tree at
avrtoolbox\libavr\source\driver\external_hardware
\nav_button. You can get this from the avrtoolbox
repository at http://code.google.com/p/avrtoolbox. You
will probably want to start with the tester library at
avrtoolbox\libavr\testers\nav_buttons.
■ FIGURE 2. Typical remote control menu
navigation buttons.
February 2012 59