DIY-SMU Chapter 4: Remote instrument control via SCPI

This chapter demonstrates the DIY-SMU SCPI interface. It explains how I added this capability using the Vrekrer SCPI parser Arduino library.
Sorry about the 20 min dead air at the end. Should I delete this video and make a new one, or just leave it?
Check out the project web site at:
www.djerickson....
www.djerickson....

[@VinisLab]

I am happy to see the implementation of scpi is going smoothly!

[@ericksonengineering7011]

Hi Vini. Thanks for your recommendation to use the Vrekrer library. Works great.

[@EEZOpen]

Hi Dave, great to see the project progress. One note: The SCPI standard command to turn on output is not OUTput but OUTPut

[@ericksonengineering7011]

Thanks, I'll fix it.

[@hullinstruments]

Would love to see some more updates about this project. Truly a wonderfully designed an executed design

[@ericksonengineering7011]

Thanks for the nice feedback. I was hoping the DIY community could embrace it, hoping I could get some boards assembled for sale. But the parts shortage mine field has made building and selling complex hardware close to impossible. Lead times are out to 2Q2023. The latest issue is Teensy 3.2 and 4.0 availability. It would suck to get boards built only to find 1 or 2 critical parts unavailable. Meanwhile, doing firmware updates and Python code are a possibility. I'll resume firmware work this winter. I have 4 fully working units, and willing to give away 1 or 2 to someone who wants to do some Arduino / Teensy coding or Python application code. Also I'm also looking towards upgrading my other projects: 18b DAC, and PS-Load.

[@hullinstruments]

@@ericksonengineering7011 yeah the part shortage has been a real slap in the face. Hopefully things get worked out, because it's affected so many random things that folks wouldn't even think of. Your SMU is one of the most well thought out and executed projects I've seen on KZbin in a long time. A lot of times folks will start something incredible like that and then just drop it in the middle of the project. (Like Marco reps and his open source measure unit) 😂. But I'm holding out hope maybe he'll pick it up again one day in the future he has all the boards and things.

[@artursmihelsons415]

Great video and update. I agree, this is very cool library. Now I want to implement it in my power supply..

[@lukegary4482]

This project is great and impeccably documented on your website, thank you Dave! Minor quibble on the firmware, I am fairly certain that the F-String macro really only applies to AVR processor based "Duinos". The Teensy you're using, being an Arm Cortex based module, should have the ability to cleanly access data in any of the physical memories in a single logical address space whereas the AVRs need additional sauce to grab data from program memory given the more stricly Harvard-Like architecture. you should just be able to mark the strings as const and let the compiler handle the rest, and check the linker script and map file to verify that data remains in flash and doesn't end up in ram after startup.

[@ericksonengineering7011]

Thanks for the feedback. Good idea. F strings were inherited from the SCPI library examples. Teensy is nice enough not to complain about them.

[@ddowlingau]

Great to see this project progressing along quickly. I will have to check out the Vrekrer library as I can see it would be useful for all sort of measurement projects. It is a great way to get some consistency into the commands accepted by different instruments.

[@Likeaudio]

What am impressive amount of work

[@bvernoux]

Very interesting project it will be even better if it could be available on github or gitlab especially to have source control / contributors ...

[@ericksonengineering7011]

Yes, definitely. I'll post it when I do.

[@ericksonengineering7011]

Check out the new github page at github.com/djerickson/diy-smu It's a start. Let me know if it's OK. Thanks, Dave

[@Sayurti]

Good Day Sir, may i know which file should i upload into the teensy? from your included files, there are 6 .ino files, which file should i upload into the teensy

[@patrickmagee774]

Amazing project, looking at the price of SMUs this could be a very worthwhile build, especially with the open source code. Would it be fast enough to script a battery simulator? Assuming you had a mode of the characteristics (which this smu could actually generate from a physical battery).

[@largepimping]

There was about 20 minutes of black footage at the end of the video. I think you need to fire your editor! :) Anyway, thanks - this project is fascinating.

[@ericksonengineering7011]

OOPS! You'd think that either the editing SW or KZbin's processor would catch this. I fix!

[@VinceAnido]

This is a really great project! I enjoy following your progress Do you have any plans to make a kit available for sale once you have a stable hardware build set? Even having just the PCBs and front panel could be a really interesting proposition...

[@ericksonengineering7011]

Good question. I'm working on the Rev2 Main board and Rev3 Amp board, hopefully these will be rework-free. I could supply assembled and tested boards and front panels as a start. Is there interest?

[@VinceAnido]

@@ericksonengineering7011 I would definitely be interested. You could also check @marcoreps 's audience for more reach

[@andpe161]

I'm interested.

[@johncook538_modelwerks]

I just found this project and I'm also interested. I bet my maker space friends would also be interested.

[@hullinstruments]

i check back to this project regularly to see if you’ve updated anything and not sure how I missed this comment. But yes there are a lot of folks interested especially since Marco reps hasn’t published his open source SMU design. I totally understand that he doesn’t really need it now that he has sponsors giving him crazy nice metrology equipment ... but there are a lot of folks out there that could really use something like this. And from the designs and files I’ve seen of Marcos… They are incredibly well designed. if he isn’t going to finish the design maybe you could get the boards and relevant info from him to implement it in your own design or just to see how someone tackles it with different methods. Would definitely Be interested in both populated/testing boards and blank boards/component kits. I visit your site and videos regularly to check for updates but also just to go over the info again. It is very enjoyable to me to see how you tackle this problem with all of the different implementations and how it evolves. I reread everything regularly because it's a lot of fun… And you did a lot of work and a great job!

[@andooy]

Awesome project, do you think you'll add sweep functions for breakdown voltage testing?

[@ericksonengineering7011]

Hi, and thanks!. Sweeps and breakdown testing could be done via SCPI commands over USB, and a Python program on a PC , no? I assume for breakdown testing, you increase device voltage and look for a rise in current. Is 0 .1 to 0 .5 second response time fast enough? If so it will do that now.

[@andooy]

@@ericksonengineering7011 That would definitely work!