How to Program Test Tools with Python - Workbench Wednesdays 66

If your test tools have a USB or LAN port, there is a good chance that they support SCPI. Using pyVISA, you can write automated test programs for most equipment without expensive software. This video explains terms like VISA, SCPI, and USBTMC. Then it shows how to use Python and pyVISA to connect to test equipment with a Raspberry Pi (or any Linux computer.)

Watch the Video:

Bonus Content:

PyVISA
RsInstrument, R&S Python Implementation (also uses pyvisa!)
Keysight IO Suite
R&S VISA
Standard Commands for Programmable Instruments (SCPI) Syntax. (web archive mirror IVI Foundation)
SCPI Specification
Blog post, Early peak at bode plot script
Snapshot of Code
Github link for code

Bill of Material:

Product Name	Manufacturer	Quantity	Buy Kit
34465A Bench Multimeter, Truevolt, 6.5 digit	Keysight	1	Buy Now
TL081 - JFET General Purpose, 4 MHz SOIC-8	ST Microelectronics	1	Buy Now
Bench Oscilloscope - 200 MHz, 1 GSa/s, 14-bit, AFG, DMM	Multicomp Pro	1	Buy Now
MXO4 - 4 Channel Oscilloscope 200 MHz	Rohde & Schwarz	1	Buy Now
HMC8043 Bench Power Supply, Programmable, 3 Output, 0 V, 32 V, 3 A	Rohde & Schwarz	1	Buy Now
RPI400-KIT-US Raspberry Pi 400 Kit, BCM2711, Quad-Core, 64bit, ARM, Cortex-A72, US PSU, US Keyboard Layout	Raspberry Pi	1	Buy Now

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Top Comments

Fred27 over 3 years ago in reply to baldengineer

Yes - complete the game (to find Santa who's gone missing) and Santa inflated and popped up behind you.
A Lego Christmas game
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baldengineer over 3 years ago in reply to Fred27

So, the game controlled the inflatable Santa?
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Fred27 over 3 years ago

A nice video. Thanks for all the useful info.

If Python isn't your thing, SCPI is also easy to use from whatever language you are comfortable with. Last year I managed to knock up something very quickly to control an instrument over SCPI from inside a video game written using Unity / C#. When you completed the Christmas-themed game a power supply inflated an inflatable Santa. Of course that could have been done many other ways, but that seemed the quickest.
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baldengineer over 3 years ago in reply to mayermakes

You know, I did not even think about a Beaglebone Black! I did briefly try out a LIbreComputer Le Potato, and it worked fine. I even showed it in the original cut. But I decided it wasn't necessary because anything running Linux will work about the same.

Keep in mind that most instruments will lock out the front panel when you start querying them remotely. So if you're trying to display measurements on a web page WHILE using the equipment, that can be tricky. But if it is for logging or monitoring, then that's a different story.
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mayermakes over 3 years ago in reply to baldengineer

if anyone has a gripe with using a pi, I can warmly recommend doing it with a Beaglebone black.
this also gave me the idea of maybe developing some sort of plug and play box with a pocketbeagle that reads your instruments(does the hard python parts) and you view the data on a webpage served by the beagle from your normal pc so the linux/windows/mac trouble are gone
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baldengineer over 3 years ago

Originally, this explanation was going to be a segment in the Bode plot episode. But it grew too long. So I started developing it standalone. The first cut for this video was 25 minutes long. It's down to 13.

Despite the lukewarm feelings towards Raspberry Pi on the internet right now, I still really liked using the Pi 400 for this task.
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mayermakes over 3 years ago

ohoh..I sense some automation i have to implement....
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