Digilent Analog Discovery 2 Review, Specs & Analysis

That's what makes the Diligent Analog Discovery 2 USB toolset such a game changer—it offers all of the elements listed above in a single portable unit that costs under $300. While it does have some bandwidth and power limitations—you certainly won’t want to toss your existing carefully curated test suite—for those that are just getting started, or don’t have a lot of room and/or a large budget, this looks like a fantastic option.

Digilent Analog Discovery 2 Specs

Cutting to the chase, here’s what the Digilent Analog Discovery 2 brings to the table:

·      Two-channel USB digital oscilloscope (1MΩ, ±25V, differential, 14-bit, 100MS/s, 30MHz+ bandwidth - with the Analog Discovery BNC Adapter Board)

·      Two-channel arbitrary function generator (±5V, 14-bit, 100MS/s, 12MHz+ bandwidth - with the Analog Discovery BNC Adapter Board)

·      Stereo audio amplifier to drive external headphones or speakers with replicated AWG signals

·      16-channel digital logic analyzer (3.3V CMOS and 1.8V or 5V tolerant, 100MS/s)

·      Digital Bus Analyzers (SPI, I²C, UART, Parallel)

·      16-channel pattern generator (3.3V CMOS, 100MS/s)

·      16-channel virtual digital I/O including buttons, switches, and LEDs – perfect for logic training applications

·      Two input/output digital trigger signals for linking multiple instruments (3.3V CMOS)

·      Single channel voltmeter (AC, DC, ±25V)

·      Network Analyzer – Bode, Nyquist, Nichols transfer diagrams of a circuit. Range: 1Hz to 10MHz

·      Spectrum Analyzer – power spectrum and spectral measurements (noise floor, SFDR, SNR, THD, etc.)

·      Data Logger - Exportable data and plot functionality

·      Impedance Analyzer - Capacitive and Inductive Elements

·      Protocol Analyzer - SPI, I2C, UART, and CAN

·      Two programmable power supplies (0…+5V , 0…-5V). The maximum available output current and power depend on the Analog Discovery 2 powering choice

·      500mW total when powered through USB. (Each supply can provide between 0mW and 500mW so long as the total does not exceed 500mW.)

·      2.1W max for each supply when powered by an auxiliary supply.

·      700mA maximum current for each supply.

·      An available Software Development Kit for programming with Python and C++, and a toolkit for programming with LabVIEW.

·      MATLAB support for the Data Acquisition Toolbox

Testing the Digilent Interface: Analog Discovery 2 Waveforms Download

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Before I get into the hands-on portion, two notes:

• Digilent has a series of excellent videos that can be found on YouTube as in introduction. While our instinct as engineers tends to be to “poke around,” a few minutes watching will save you some time getting to know the system.

• USB oscilloscope software installation is a breeze, and the overall tabbed interface style is intuitive to use for anyone that uses a modern web browser… so anyone. The tools can also be undocked into windows, if needed. One excellent feature is that tabs have a play/stop button, so you can easily see how stopping an input affects an output tab, without directly switching between the two. This WaveForms software is free to download from Digilent, so you can try out the interface without actually having one of these units available.

Analog Discovery 2 USB Oscilloscope Software

The Analog Discovery 2 offers lots of available scope options, and it’s easy to zoom in on certain parts of the waveform

The oscilloscope is arguably the most fundamental tool in this package, measuring repeating signals, as you’d expect. Time divisions are selectable via a dropdown menu, or you can zoom/expand via the mouse wheel or right mouse button. The left button can drag the waveform left and right to vary its position.

Two channels are available for measurement. While the 100MS/s and 30MHz ratings are certainly not the best on the market, they’re more than adequate in many contexts. There are a huge number of options and auxiliary displays available, like measurements, logging, a zoom screen, and audio output. Where one might see an advantage over dedicated scopes is how well it's integrated into its computer environment. To this end, one can program it using JavaScript, and there’s even an available software development kit that gives users the ability to create custom PC applications. There are a wide variety of import and export features, and you can always screenshot anything you need to remember later.

Note that the 30MHz rating is used when using probes with a BNC adapter, available separately, or as part of the Pro Bundle. The rating is actually 9MHz when using only leads, as tested here.

Waveform Generator Test

Two generated waveforms measured on the oscilloscope

This tool can be used on a fairly basic level, and in more advanced contexts, like combining different mathematically based signals, simply drawing in a plot, or even importing audio files. The interface defaults to “Simple,” which shows options like the type of wave, frequency, and amplitude. Once you’re ready for more, the interface can be switched to more advanced modes, giving you access to a wide array of new options.

As with the scope’s inputs, the signal generator features two output channels, which function independently of the oscilloscope. You can, therefore, use the two tools in tandem to generate signals and see the results. This is where the play/stop button on the tabs is very useful, in order to switch things on and off in an instant.

Other Tools:

StaticIO can measure multiple IO channels at once, represented here as 7-segment displays.

While I didn’t get to test every tool in this device’s massive test arsenal, a few other things did jump out. The power supply and voltmeter both feature two channels, providing an interesting advantage over more traditional tools. Power generation is somewhat limited at 500mW total over USB, but these tools present an interesting option for impromptu desk measurements.

The protocol analyzer, for signals such as UART, SPI, and I2C, should also be very useful, and the staticIO has a variety of test applications. The spectrum analyzer, and other more advanced tools, could be great as a portable solution for “old pros,” or as a gateway into a world of experimentation that you may have yet to explore.

How to Use Analog Discovery 2: A Professional Tool?

Is the Analog Discovery 2 for “pros,” however you define it? Given the fact that its labeling notes that it “costs less than a textbook," the intended audience is certainly for education and serious hobbyists. That being said, if you need to take your tools on the road without exorbitant baggage charges, this could be e a very attractive option for field work. It could also function as a secondary device for quick analysis, or even as a way to examine the efficacy of certain tools before taking the plunge into multiple dedicated devices that total up to much more.

All that being said, unless you have just the right desk setup—devices like this often end up being awkward to use. Ideally it’d have it’s own screen and controls, independent of the laptop on which you’re trying to take notes or look up data. To this end, the software is actually compatible with the Raspberry Pi 4 single-board computer, and in an upcoming article, I’ll show how to build a dedicated platform around this versatile device, similar to what’s outlined here.