August 2016 55
THE LATEST IN NETWORKING AND WIRELESS TECHNOLOGIES
your PC to produce several very useful test instruments.
The rest of this story gives some examples.
The Analog Discovery 2
The Analog Discovery 2 is a full blown VI in a small
box as shown in Figure 1. It is made by Digilent, Inc.,
which is a company that is owned by National Instruments.
All of the ADCs, DACs, and other circuits are in the small
enclosure. The whole thing is powered by the + 5 volts
from the USB connection to the laptop. The VI software
that creates all the instruments is called Waveforms and is
installed on the laptop. The software runs under Windows,
Apple Mac OS, or Linux. The colored wires are all of the
inputs and outputs (I/O) that connect to external circuitry.
This photo shows the outputs from two function generators
displayed on the dual trace oscilloscope. Special pins are
used with the I/O leads to connect to the circuits on the
The amazing thing is what the Discovery 2
implements. Take a look at what’s inside the box:
y Two-channel USB digital oscilloscope (1MΩ, ±25V,
y 16-channel pattern generator ( 3.3V CMOS, 100
y 16-channel virtual digital I/O including buttons, switches,
• 250 m W max for each supply or 500 m W total when
powered through USB
• 700 mA max or 2.1W max for each supply when using
an external wall power supply
It literarily is a whole test bench of instruments
that you usually need when experimenting, designing,
troubleshooting, or otherwise playing around with circuits
or equipment. All this costs is $279. Individual test
instruments with these specs would cost you thousands of
dollars. Save up. It is worth it.
A lower cost version called the Analog Discovery is
also available for $249. The scope and AWG bandwidths
are only 5 MHz, and the power supply current capability
is more limited to 50 mA. This will restrict your range of
applications. Go for the $30 extra and get the Discovery
2. I also recommend their BNC connector adapter board
that lets you use standard scope probes that will give you
the full 30 MHz bandwidth. They also have a wall wart
transformer power supply if your power supply needs
exceed the capability of the USB port.
There are other similar products on the market. A
couple of years ago NI introduced their myDAQ product
(see Figure 2). This device uses a reduced version of
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FIGURE 1. Digilent’s Analog Discovery 2 virtual
instrument package. Connect it to a laptop via a USB
cable and you have a full work bench of test equipment.
FIGURE 2. National Instruments’ myDAQ virtual
instrument and educational trainer. It is widely used in
colleges and universities giving students a portable lab.