EEVblog #1190 - Mailbag Review Bonanza

[EEVblog]

A look at three major products in this lengthy Mailbag.



SPOILERS:

LabJack T7-Pro Multifunction DAQ with WiFi, Ethernet, and USB
https://labjack.com/products/t7

15:56 Balena Fin Raspberry Pi Compute module industrial computer
https://www.balena.io/fin/

29:29 Dodgy truck LED tailight assembly

38:00 Joulescope: Precision DC Energy Analyzer Kickstarter
With lengthy discussion on current measurement autoranging.
https://www.kickstarter.com/projects/jetperch/joulescope-precision-dc-energy-analyzer

[gir]

Regarding the absence of a microSD card: At $WORK we had dozens of µsdcards in our custom monitoring system fail (the Pi is known for this). Offering only the more reliable eMMC storage is (imho) the correct way to go.

[johnlsenchak]

I thought the lab  was flooded, I would  have  figured    it would have been a  swimming  pool  by the time you did this video  LOL

[highlanderIII]

Dave, did you just pull the RF connector off the WiFi module of the LabJack (at 4:53) ?
None of this new Wi-Fi rubbish, I'll use the DB25 connector! 

OK, coax connects to Y1, not to J1 (visible at 6:03).   

[pinchies]

That labjack? I was wondering where it was used.

Coincidentally, I just saw one in the field today - in a quantum computer: https://youtu.be/6yaY4Fw-ovM?t=242

Hope the lab is drying out Dave!

[darik]

I thought the lab  was flooded, I would  have  figured    it would have been a  swimming  pool  by the time you did this video  LOL

At the very end he mentions that it's starting to hail outside....

[nixfu]

Dave, I liked that you did long segments in this mailbag.   It's nice to have a mailbag like that sometimes.  I know you feel like you have to do the wham-bam-thank-you-mam style you often do because you are so backed up with mail.  But personally I like this style.

[chickenHeadKnob]

Dave, I liked that you did long segments in this mailbag.   It's nice to have a mailbag like that sometimes.  I know you feel like you have to do the wham-bam-thank-you-mam style you often do because you are so backed up with mail.  But personally I like this style.

The segment on the joule-scope would have been a decent show all by itself. Fast, good  and information dense - well done Dave. It was obvious  you have been thinking about the design issues involved with this type of instrument. I did wish to know which ADC is being used and if the onboard STM32f091 "inguard processor" ADC+DACs are utilized, but that is just nit-picking.

[EEVblog]

Dave, I liked that you did long segments in this mailbag.   It's nice to have a mailbag like that sometimes.  I know you feel like you have to do the wham-bam-thank-you-mam style you often do because you are so backed up with mail.  But personally I like this style.

This longer rambling "real time first try" format is actually easier and quicker to produce than a more polished mini-review.

[EEVblog]

Dave, I liked that you did long segments in this mailbag.   It's nice to have a mailbag like that sometimes.  I know you feel like you have to do the wham-bam-thank-you-mam style you often do because you are so backed up with mail.  But personally I like this style.

The segment on the joule-scope would have been a decent show all by itself. Fast, good  and information dense - well done Dave. It was obvious  you have been thinking about the design issues involved with this type of instrument.

I thought about splitting it out into a 2nd video but it wasn't polished enough for a standalone review IMO, it was just me rambling and doing a first time play around with it, so decided to keep it in the mailbag.

[EEVblog]

I thought the lab  was flooded, I would  have  figured    it would have been a  swimming  pool  by the time you did this video  LOL

At the very end he mentions that it's starting to hail outside....

That's when I headed downstairs to film it and I came back to a flooded lab 

[splin]

The segment on the joule-scope would have been a decent show all by itself. Fast, good  and information dense - well done Dave. It was obvious  you have been thinking about the design issues involved with this type of instrument. I did wish to know which ADC is being used and if the onboard STM32f091 "inguard processor" ADC+DACs are utilized, but that is just nit-picking.

ADS7056 - U22 and U26. That Dave happened to show it in the Digikey listing was presumably just chance because it happens to be the cheapest 2MSPS+ 14 bit ADC, and presumably why it was selected for the Joulescope (but underclocked at 2MSPS for some reason).

[cjurczak]

Where can I doing those high resolution photos? Love to see close yours of the PCBs if possible!

[EEVblog]

Where can I doing those high resolution photos? Love to see close yours of the PCBs if possible!

https://www.flickr.com/photos/eevblog/46486019735/in/dateposted-public/

[cjurczak]

No bottom side?

[artag]

Huge ++ for the phoenix connector on that Balena board. I really hate using power jacks or USB for permanently-assembled systems. I usually end up fitting some sort of expansion board to pick up the power input on 0.1" headers.

I also didn't realise the compute module supported uPCI  - that's a pretty unusual feature for a small, cheap(ish) board. Must remember that next time I need an embedded board with PCI.
 

[gearshredder]

Dave, for the LED tail light, the supply goes up to 30V as a 24v Fiber Nickel Cadmium (20x1.2v) nominal pack will sit at a 30v float voltage. These FNC cells are used in rail passenger vehicles but have different grades for engine starting, UPS, and general purpose.
A lead acid style should only reach about 28v or so.

[CChin254]

Here are the rest of the ICs used in the front end of the Jetperch Joulescope precision DC energy analyzer: