The Big Picture
I was gassed when I realized that a Raspberry Pi (RPi)
could run a plotting program like “Gnuplot” and generate
spiffy real time plots of wind speed on one of the small
LCD displays from Adafruit (refer to Figure 1). The best
part was customizing the display to look just the way I
wanted it to.
The seven inch 1280 x 800 display looks great on my
wall. The colors are vibrant and the resolution is more
than I could hope for. During operation, the RPi updates
the peak wind speed once per minute, 1,440 times a day,
24/7, and resets at midnight. It’s fun to watch the peaks
climb higher and higher, as I wonder if the house is going
to blow away.
The schematic diagram of the project is shown in
Figure 2. I realize that some of the functions could be
combined to reduce the parts count, but I already had
most of them in my stock so I shoved them all into a box
and started programming. Figures 3 and 4 show the box
mounted under my desk.
As seen in the schematic, the project starts with the
anemometer on the left. Many years ago, I purchased a
Davis Model 7911 anemometer and it’s still working today
(see Figure 5). I checked eBay and there are some less
expensive units from overseas, but their outputs may not
February 2016 29
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■ FIGURE 1. The Adafruit seven inch 1280 x 800 LCD
plots the max wind speed at one minute intervals,
1,440 times a day.
■ FIGURE 2. An Arduino Mega 2560 is
the heart of the system and coordinates
all the functions.
www.adafruit.com (displays and Raspberry Pis)
www.dfrobot.com (cheap 2x16 LCD shield)
www.digikey.com (general components)
www.parallax.com (SX28 IDE)
Arduino Cookbook, by Michael Margolis, 2013