DSO138 Scope, Acrylic Housing Assembly, and USB Power

Every now and then, I find out about something that is simply absurdly cool and useful for the price.

This is a companion discussion topic for the original entry at https://www.sevarg.net/2016/11/26/dso138-scope-acrylic-housing-assembly/

(Comments from Blogger)

2017-01-26 by MikePet

Hey Russell – just got one. I only need it to look at comms for an RS485 differential network that’s pretty small. The price is right. Thanks for the post – I think it’ll be very helpful for me as I set it up and try to use it. Cheers!

2017-01-26 by Russell Graves

Good luck! You can definitely watch serial signals flowing across at reasonable baud rates, but the data window is small enough that you can’t get a huge amount of data. If you’re just looking to verify that data is flowing, it’s perfect, and I’ve used that for determining that I had baud rates all wrong coming out of a high speed UART.

2017-01-26 by MikePet

Finally got it hooked up with a step up transformer, and mounted in a rectangular metal case that United was handing out in First Class. Lots of hot glue to bolt things down, and a dremel tool to knock a hole out for the probe bnc connector, and I’m golden.

It’s pretty decent. Doesn’t have a big screen – you’re right. Not going to be able to see a lot of data. I was kind of hoping that I’d be able to read values off of the mini usb that’s right next to the UART headers, but I’m guessing not. Oh well. $26 assembled – can’t beat it, though.

Thanks again for your article. I’ll keep the operation notes section that you wrote as a reference. Cheers!

2017-02-03 by Stan

Real nice article!!! I had just finished assembling mine…then I go read about it! Although I got it together and saw it running, I am now doubly excited to use your tips and make it better. Your the man!!! Thank you.

2017-03-26 by Brian Hopkins

So, I’m exploring learning about connecting unlikely devices together with these types of options. I don’t have the formal understanding you obviously do, but I am glad you’ve decided to make this post. I am greatful for affordable and handy devices like these that can be managed and mastered by semi-novices. No trouble with powering, but some in the consistency. Keep the insights coming.

Brian Hopkins @ Micro Tips USA

2017-07-06 by An old fart engineer

I just ordered one of these things. Are you aware there’s an open source version of the firmware on Github?

GitHub - ardyesp/DLO-138: An open source firmware for DSO-138 O-Scope

2017-07-06 by Russell Graves

I was not - nifty!

Though I’m not terribly likely to mess with that firmware - I ended up buying a much, much nicer scope (4 channel, 100MHz, capable of handling mains voltage) for some of my other project and analysis work.

2017-07-07 by An old fart engineer

As far as ‘real’ scopes are concerned, we’re more or less in the same frame of mind. I own an old Fluke 97 ScopeMeter that’s really handy for some stuff, but I hate the UI and older tech display. In my working days I spent a lot of time with a Tektronix 465 and intend to score some sort of equivalent eventually.

But the DSO-138, when seen as an Arduino IDE-compatible ARM Cortex board with an on-board display and some interesting analog hardware, just might be interesting to play with. We retirees gotta keep those brain cells working, ya know.

2017-09-28 by Unknown

Good day. From manual, maximum input in default BNC clip is 50 Vpk. Why ? Maybe i missed something, but voltage max. of STM CPU is 5V. So question is: I need measure 24 DC voltage, do I need 1:10 probe, or 1:1 is good ? Thanks.

2017-09-30 by Russell Graves

The measurement is handled through an array of resistors and such that deals with the proper scaling. If the manual says it can handle 50Vpp, it should be able to, but… were it mine, I’d probably use the 10:1 probe if I had one laying around. I don’t really trust Cheap Chinese Gizmos to the maximum listed in the manual - I’ve blown up more than a few things learning that lesson.

2018-02-12 by Anonymous

Hi Russell,

Thanks for sharing your knowledge ! I just updated my DSO-138 following your article, I would probably never have without it.
There comes a noobish question :is it possible to directly connect an USB plug +5V to the output of the 5V regulator instead of stepping it up first and feed it to the standard 9V power input ? Would the negative voltage generation (AV-) fail to operate ?
Keep educating us… or me at least :wink:

2018-02-12 by Russell Graves

I’m not sure. It works fine with the little boost converter, and I had that laying around, so I didn’t dig any deeper into the board. You should be able to find the schematics and see how it works!

2018-05-16 by TheIncredib13

I got the kit with smd premounted, so it was easier to deal with, since I’m quite a beginner. The mounting and soldering was pretty straight forward, but the case wasn’t. I messed with it for like an hour and gave up then. Unfortunately I forgot about calibrating the device, so when I found your excellent how-to, I was so excited to get the case finished, that I needed to disassemble it right after I got it all together…

Since the firmware-update needs JP1 and JP2 shorted, I had to disassemble it anyway, since I was still on 040. I’m on 061 now (only better support for the LCD, no function change). I used transparent labels with my Dymo (label-tapes) to name the sliders, switches and connectors(3-pin UART and 4-pin SWD (I have no idea, what to do with that, but I named it nonetheless. I left out USB, since it has no function anyway), so I can use the device, without peeking throug the case.) The tapes are somewhat blurry, but the with the bold black letters it looks pretty good. So thanks for your excellent how-to, I saved it as pdf, just for the case, I have to disassemble it again, and get lost through reassembling…

2018-06-24 by Unknown

As mentioned this is a basic scope- I’m into synthesizers so it is really useful to have a visual representation of the waveforms producing the sounds - accuracy and precise calibration is not an issue. Great blog. Thanks

2019-05-26 by 49astro

Hello Russell

Thanks for this. And I’d much rather read about it like this than watch a video.

2019-11-10 by Unknown

An Instructable on assembling a 3-D printer said he used Loctite and the fumes from it crazed and shattered the acrylic parts. You might test it on Plexiglas overnight.