■ FIGURE 10. LED strip connection.
GitHub site for this driver shows you how to include the
driver into your code and has a “testMe.js” application
that will test all the methods in the class (this is included in
the article downloads as well). The testMe.js app is a
useful resource for understanding how your program
should make calls to this driver. You’ll find a testMe.js for
all the drivers in this project. In fact, testing is standard
practice for writing Node.js modules. You’re expected to
include a test process and document how to use it.
methods for sending commands to the LED strip. For
example, the command:
Quad Alphanumeric Display Circuit Detail
sets all the LEDs in the strip to a dim red color. The
■ FIGURE 13. Alphanumeric display connection.
■ FIGURE 12. Alphanumeric bus.
The alphanumeric displays are directly connected to
the RaspPi’s I2C bus (pins 3 and 5). Take a look at Figures
12, 13, and 14. This is a straightforward connection to the
I2C bus of each alphanumeric display. No additional
components are required. However, I’m not using a bus
configuration for the I2C communications. I’m using a star
configuration to connect each of the four quad
alphanumeric displays. This allows me to use straight-
■ FIGURE 11. LED strip schematic.
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