Recent Posts

1

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by mrisco on Today at 12:16:12 pm »

...You show signal that has 10ns period, measurements measure 20ns period, and Counter measure 140 Hz (should be cca 100MHz)..
Am I confused or what?

Just ignore that, it was noise at my desktop and the screen shows a little piece of a larger noise. So, the counter is counting anything.

2

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by mrisco on Today at 12:12:42 pm »

Is your modified app fully functioning when installed? i.e., able to save screenshots, etc... 

Oh! I was on page 67 of this now 106 pages thread and saw a modification of the UI. So, I got down to work. I think that I just reinvented the wheel. I should have read some more pages, that could have made my job easier by working on what you have already done.

I had the same problems as Andybig had. My application is signed with my own development key, so it can't share the system user space. So, in the beginning if the application is installed normally and granted root access but not system access, it can't take a screenshot. For me it is not really a big problem because I use the webui to take the screenshots.

3

Other Equipment & Products / Re: Crimpin’ ain’t easy (or: best hobbyist crimping tool/system?)

« Last post by tooki on Today at 12:10:04 pm »

OK, I see why I didn’t find the original JST tools on Misumi: apparently, they’re “general purpose tools” and not the “dedicated tools” category I naively looked in…  (So far, I’ve found at least three categories which contain subcategories with crimp tools. What an awful, awful website, with respect to taxonomy.)

Anyhow, their prices for the tools are not low, so at 50% they’d be good prices, but not at full price.

4

Test Equipment / Re: New 2ch pocket DSO+SG - Zeeweii DSO2512G

« Last post by Aldo22 on Today at 12:09:38 pm »

I want to ask: can I simultaneously check both adapters with both probes, connecting each of them to its own minus, or is this not possible?

I don't know exactly what you mean.
The Zeeweii itself is not grounded (earth) when it runs on battery, but of course the two BNC grounds (minus) are connected in the oscilloscope.
Maybe someone else can help.

5

Projects, Designs, and Technical Stuff / Homebrew Lock-In Amplifier

« Last post by Picuino on Today at 12:03:59 pm »

Some time ago I bought the necessary chips to assemble a homebrew lock-in amplifier and I would like to assemble it and experiment with it.
Has anyone assembled the lock-in amplifier based on the AD630 that is circulating on the internet?
With which PCB can it be assembled with guarantees that it will work well?
Has anyone experimented with it and what interesting experiments can be done?
I know there are a lot of questions, but they can be summed up in just one. Can anyone tell us about your experiences with this instrument?


Homebrew Lock-In amplifier:
https://www.holographyforum.org/data/pdf/aa-Collection_a_k/aa-Laser/aa-lockin/Homebrew_lockin_amplifier.html
https://www.instructables.com/Lock-in-Amplifier/

More professional version:
https://physicsopenlab.org/2019/08/20/lock-in-amplifier/
https://www.ebay.com/itm/275596051897?epid=2282365081


What is a Lock-In Amplifier:
https://en.wikipedia.org/wiki/Lock-in_amplifier
https://www.zhinst.com/en/resources/principles-of-lock-in-detection
https://www.thinksrs.com/downloads/pdfs/applicationnotes/AboutLIAs.pdf
https://www.liquidinstruments.com/digital-lock-in-amplifier/

6

Test Equipment / Re: SDS800X HD - Issue disscusions - is it me, or the scope?

« Last post by eTobey on Today at 12:02:12 pm »

Another issue:
When missing the "+" or the button for resetting statistics, the measure menu opens. It is already too hard, to hit the resetting button. 
 

See picture.

7

Test Equipment / Re: Hacking the Rigol DHO800/900 Scope

« Last post by shapirus on Today at 12:00:11 pm »

All this separate work really needs a github repo to track. If not for direct use for the recompilation of the .apk, then at least as a source to make diffs against and patch your own decompiled .apks.

imho step by step guide how to hex-edit/patch and which part is what, is what i more need.. and then others can continue the work on other parts and produce step by step again, until majority of parts are hacked or known. or a readable script or table in file (byte position, byte value to patch)... so end users also can freely customize which part he/she prefer to change which part to stay default. ymmv.

UI edits are (at least mostly) all text, no hex editing is involved.
The important part in making it possible is to disable the signature verification, and from there it's all trivial using apktool.
The valuable part, that should not be lost, and which therefore should be hosted in a git repo, is the actual changes to the decompiled text files that tweak the UI.

8

Test Equipment / Re: SDS800X HD Wanted Features

« Last post by RAPo on Today at 11:58:03 am »

I use the scope with a web interface, and hardly use this physical button, so if I can control it via the web interface I am happy, otherwise I would be highly dissatisfied

There could be some space be freed in the screen. Its not jut the "Meas" button. The hardware buttons work very good!

9

Thermal Imaging / Re: Help with "80 series Thermal imager" by insight vision services

« Last post by Niall135 on Today at 11:57:13 am »

Thank you Fraser and Bill for all the help and advice on this series 80, but i have had no luck recomissioning the power supply.
The 12 battery input bypassing the 240v transforer did not help as the output voltages were still missing.
Replaced 2 suspect mosfets to no avail, i think power distribution pcb with the focus pots etc has succumbed to age (i know what that feels like). 
I should have taken Frasers sage advice ad not spent so much time and effort on it.
But all is not lost. I have TIC fever now and got my wife to buy me a DH-BF5421-T for my birthday. It came with a blackbody and 2 tripods.
My plan is to install the microbolometer in the series 80 body where i can utilise the large 35mm f.07 lens and the focusing servo.
So far so good as im getting great images in preliminary tests.  I just have to fabricate a carriage to get the sensor centralised. Ill post on this seperatly.
But this means all the boards from the series 80 are available for spares along with the pevicon tube. First refusal to Fraser and Bill. DM me if they are of interest.

10

Microcontrollers / Re: How do you search for a microcontroller ?

« Last post by artag on Today at 11:54:10 am »

There are an impossibly large number to select from. As Smokey implies, the learning curve for an unfamiliar one can be brutal - ST are particularly complicated to set up and their Cube system to help generates code that many people despise.

If you have any existing systems, use a top-end device within that (eg Teensy within the arduino ecosystem) to produce a POC at low cost in terms of learning effort, and look out for problem areas such as cost, speed etc. You might prototype on teensy and then go to  an FPGA with embedded processor once you have a good idea of your needs.

Don't commit to a device you have no experience of and have to spend 6 months learning before you can be productive, only  to find there's some new requirement, constraint, or bottleneck that forces you to change.