Software Defined Instrumentation Hack Chat

Ben Nizette will host the Hack Chat on Wednesday, April 27 at noon Pacific.

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Imagine, if you will, the perfect electronics lab. Exactly how it looks in your mind will depend a lot upon personal preferences and brand loyalty, but chances are good it'll be stocked to the gills with at least one every conceivable type of high-precision, laboratory-grade instrument you can think of. It'll have oscilloscopes with ridiculously high bandwidths, multimeters with digits galore, logic analyzers, waveform generators, programmable power supplies, spectrum analyzers -- pretty much anything and everything that can make chasing down problems and developing new circuits easier.

Alas, the dream of a lab like this crashes hard into realities like being able to afford so many instruments and actually finding a place to put them all. And so while we may covet the wall of instruments that people like Marco Reps or Kerry Wong enjoy, most of us settle for a small but targeted suite of instruments, tailored to our particular needs and budgets.

It doesn't necessarily need to be that way, though, and with software-defined instrumentation, you can pack a lab full of virtual instruments into a single small box. Software-defined instrumentation has the potential to make an engineering lab portable enough for field-service teams, flexible enough for tactical engineering projects, and affordable for students and hobbyists alike.

Ben Nizette is Product Manager at Liquid Instruments, the leader in precision software-defined instrumentation. He's the engineer behind Moku:Go, the company's first consumer product, which squeezes eleven instruments into one slim, easily transported, affordable package. He's been in the thick of software-defined instrumentation, and he'll drop by the Hack Chat to talk about the pros and cons of the virtual engineering lab, what it means for engineering education, and how we as hobbyists can put it to work on our benches.

Event Logs

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Hack Chat Transcript, Part 2
Dan Maloney • 04/27/2022 at 20:04 • 0 comments

Dan Maloney12:44 PM
I'm curious, how are the filters in the FilterBox implemented in hardware? Do you switch LC elements in and out with relays or analog switches?

Ben Nizette12:44 PM
@RichardCollins there's no doubt that we're at the start of a push for SDI in education, it's not well established. Bleeding edge is a bit strong IMO but when labs have been using the same scopes and power supplies, with different screens and button layouts only, for 20++ years, sure there's a change to the pedagogy required to support this tech. But I think it's worth it, I'm not alone, but I'm also not without opposition :-)

Mark J Hughes12:44 PM
Man -- if someone could write their own firmware for that, my hat would be off to them. I stare at FPGAs like they're ouija boards :)

Ben Nizette12:45 PM
@Myself We're launching an open access FPGA model for Go in June, it's already available for Moku:Pro. Called Moku Cloud Compile it does require that you send your HDL to our servers to be built so we can optimise it for our driver framework

Mark J Hughes12:45 PM
Man you guys are brave.

Ben Nizette12:46 PM
@Dan Maloney All DSP my friend! You can load in FIR or IIR coefficients, or simply drag lines around on a bode plot until you like the look of the transfer function and it all updates on the device in real time

Dan Maloney12:46 PM
"Wizardry" was going to be my other suggestion...

Mark J Hughes12:47 PM
Definitely "Wizardry"

Ben Nizette12:47 PM
Yep that's closer. Our DSP and FPGA folk mostly come from a high precision metrology background, they're mostly PhDs, and they are absolutely wizards

RichardCollins12:48 PM
The hardware is changing so fast now. I was reading about 100 Gsps devices. And the prices drop then rise, drop then rise. If someone buys your box today, it will be obsolete in 6 months. No amount of software will change a 10 Msps ADC into a 100 Gsps one. And DATA is the key to any application but you are just putting tiny snips on the screen and letting student play around. All the real problem now use massive machine learning and that means stored and accessible data, open and shared algorithm development, and global sharing over years or decades. 50 million variations for what you can do with a box is not as useful as a few hundred where the student masters it, and applies to real problems - in a community of peers and potential employers and collaborators.

Ben Nizette12:48 PM
I was actually surprised, amazed and excited that I could design a bandpass filter with around 10kHz width on a 1MHz carrier in order to view an AM radio station in isolation in the time domain, then drag the band over to the next station etc. Very cool

Myself12:49 PM
So, last week I was doing a little work in a power supply that was made in 1967, the company is long gone but the schematics are available, the parts are commodity, and power supplies are universally useful. How much of this instrumentation will be working and maintainable in 50 years; where do I go for a cloud compiler in 2078?

Mark J Hughes12:50 PM
Are you seriously asking him to predict 55 years in the future?

Ben Nizette12:50 PM
@RichardCollins If you need more than 30MHz bandwidth then fair play to you sir. Again if we take the education space, they haven't done anything outside of this capability for 20 years and may not for the next 10+, excepting RF and IoT. And yep that's important, no denying, but we can still cover all but one or two courses in a full EE degree. But I get your point, DSP and SDI is awesome but you do occasionally need to buy new things! Just with SDI, you don't need to buy them as often (probably)

Myself12:51 PM
I'm asking whether the closed nature of the compiler might ever change.

Mark J Hughes12:51 PM
In 55 years time?

Mark J Hughes12:51 PM
Yes.

Mark J Hughes12:51 PM
Yes it will.

Dan Maloney12:52 PM
But a power supply is an entirely different beast than a spectrum analyzer, right? And how many SAs or oscilloscopes made in the 1960s are still relevant today?...
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Hack Chat Transcript, Part 1
Dan Maloney • 04/27/2022 at 20:03 • 0 comments

Dan Maloney11:58 AM
Hi Ben, welcome aboard. And good early morning to you as well ;-)

Dan Maloney11:58 AM
We'll get started in just a minute

Ben Nizette11:59 AM
Thanks Dan! No worries, it's still dark out but my coffee's darker. We're good here!

Dan Maloney12:00 PM
OK, folks, let's get started. I'm Dan, I'll be modding today along with Dusan as we welcome Ben Nizette to talk about software-defined instrumentation!

Myself joined the room.12:00 PM

Dusan Petrovic12:00 PM
Hello and welcome everyone!

Moaddeli joined the room.12:00 PM

Dan Maloney12:00 PM
Hi Ben! Can you start us off with a little about yourself and how you got where you are?

Ben Nizette12:01 PM
Yes no worries! So these days I'm a Product Manager for Liquid Instruments, focusing on the Moku:Go, our education and maker product.

Dan Maloney12:01 PM
(And a sincere thanks for joining us from Australia, where it's still oh-dark-thirty-ish)

Ben Nizette12:01 PM
Before that though, I’m an Electronics and Software nerd, I’ve been sticking LEDs in power points for literally as long as I can remember. I kind of forgot to stop studying so ended up with two degrees (BEng and BSc) and four majors (EE, MechE, CompSci and Theoretical Physics). And I still wasn’t done, I started lecturing Embedded Systems and a few other courses at the ANU too, I did that for about 5 years.

Ben Nizette12:02 PM
Apart from inhaling solder fumes, I also enjoy outdoors stuff like paragliding, hiking etc. Not mountain biking anymore, too many scars from that already!

Ben Nizette12:02 PM
And yes I'm based in Canberra, Australia

hexum06412:02 PM
Tnx all

Dan Maloney12:02 PM
Are the scars from biking or from school?

Ben Nizette12:03 PM
Haha mostly biking but, yennow, I did say I was a nerd too and we all know how those go in high school!

irishutopia joined the room.12:04 PM

Ben Nizette12:04 PM
Back at Uni though, while I was studying, I was also running a business doing electronic product design, mostly for start-up companies. I ended up making nearly 30 products in that time, before deciding to settle down and join one of those companies full time. That was Liquid Instruments!

Randy joined the room.12:04 PM

Randy12:05 PM
How would you characterize the difference between the Go:Moku and the Analog Discovery devices?

Dan Maloney12:06 PM
I'd love to hear more about that freelance design stuff, but I guess my first question is: what are the trade-offs that you have to accept when you're rolling multiple instruments into a virtual platform?

Ben Nizette12:06 PM
I reckon AD2 is kind of like Windows XP. Everyone gets it cheap or free, it has good market penetration because at the time it launched there wasn't a lot of competition. It does the business, but people don't generally really *like* it. We're more like a Mac device. We provide a great user experience, we work every time, and we offer more power to the professionals who use it

Ben Nizette12:07 PM
I reckon Red Pitaya is the Linux of that analogy and given the audience, perhaps pitching myself as Mac isn't quite right

Ben Nizette12:07 PM
but you get the idea!

Dan Maloney12:09 PM
Say what you will about Macs, but you've got to admit that Apple product design is top-notch...

Ben Nizette12:09 PM
@Dan Maloney Yes trade-offs! The main one is that you have a single analog front end for everything. Really that is the biggest issue when you're talking about RF and SpecAn type applications and you don't have a mixer, so are limited to 10s or 100s of MHz. Traditional SDI (like AD2) is also limited by the performance of the PC and the link to the PC. Moku does its SDI on an FPGA inside of the device itself which means the performance is as good or better than most "normal" stuff

Randy12:09 PM
Thanks, looking for info to convince the powers that be that Go:Moku is a better choice to go with.

RichardCollins12:10 PM
I am reading the Moku data logger specs. It won't go under 10 sps? Is that flexibility? And no bit size mentioned....
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