This week’s EYE on NPI (video) is all about discovering new things – the Digilent Digital Discovery with High-speed adapter bundle.
The Digilent Digital Discovery™ is a combined logic analyzer and pattern generator instrument that was created to be the ultimate embedded development companion. Digital Discovery was designed to optimize channels, speed, and portability. A small form factor facilitates easy storage and provides a whole suite of advanced features to allow you to debug, visualize, and simulate digital signals for most embedded projects. Digital inputs and outputs can be connected to a circuit using simple wire probes or breadboard wires; alternatively, the Digital Discovery High Speed Adapter and impedance-matched probes can be used to connect and utilize the inputs and outputs for more advanced projects.
We’re big fans of the affordable and powerful Digilent Analog Discovery so when this logic-analyzer version popped up on https://digikey.com/new we snapped it up to check out. The specifications of what you get, for the price, are pretty amazing:
- 32-channel digital logic analyzer (1.2…3.3V CMOS, 8 channels at 800MS/s*, 16 channels at 400MS/s*, and 32 channels at 200MS/s)
- Digital Bus Analyzers (SPI, I²C, UART, CAN, Parallel)
- 16-channel pattern generator (1.2…3.3V CMOS, 100MS/s)
- 16-channel virtual digital I/O including buttons, switches, and LEDs – perfect for logic training applications
- A programmable power supply of 1.2…3.3V/100mA. The same voltage supplies the Logic Analyzer input buffers and the Pattern Generator input/output buffers, for keeping the logic level compatibility with the circuit under test.
In particular, 32 channels of 200 MS/s logic analyzer input is rare to see in a sub-$1000 logic analyzer. 8 channels of 800 MS/s is also incredible. If you need that kind of speed, it’s very hard to find an affordable analyzer. The wide/fast rates means this analyzer would be great for analyzing wide 8/16/24/32 address/data busses that normally you wouldn’t have enough pins for. You could also check on fast protocols that normally aren’t logic-analyzer friendly like RGB matrix and parallel TFT displays.
Inside is a Xilinx SPARTAN FPGA and some memory for buffering signals. Like many logic analyzers, the Digital Discovery connects over USB and uses free desktop software for communication. The software in this case is called Waveforms, and is available for Mac, Windows, and Linux, including Raspberry Pi. The same software is used for the Analog Discovery, so if you’ve got one of those, it’ll be familiar. The software is powerful, and has a lot of options and capabilities, so we definitely recommend going through some of the tutorials available on Digilent’s site, like this nice walk-through on analyzing an old-school NES controller – here’s a hint, it uses a serial latch!
What I use logic analyzers for is usually decoding I2C and SPI transfers while writing drivers. So I was happy to see a range of built in analyzers such as I2C, UART, CAN, even HDMI! To test it out, I connected the analyzer up to a BNO080 sensor I’m working on. I enabled I2C datalogging on the two initial pins. You can see the data stream with decoded hex values and read/write flags on initial addresses. You can also open up the events tab to see the data as a list with timestamps. The event data (or even the raw pulses) can then be exported to a spreadsheet.
There’s also a powerful scripting system. You can perform analysis, read data and decode protocols. There’s also a logic waveform generator you can script as a simulator for devices.
We’re pretty confident saying that for the price, this is the fastest, most powerful, capable and customizable logic analyzer you can get. And for students, it’s super affordable and easy to store. Pair this up with an Analog Discovery for a full EE lab without giving up tons of desk space.
Pick up a Digital Discovery from Digi-Key today at https://www.digikey.com/short/
Also, here’s Diligent’s video (it’s a little long, but it’s ok to play whole thing, it’s a good vid)
