Recent Posts

1

Programming / Re: Linux Dependency Black Hole

« Last post by tatel on Today at 11:47:30 am »

28 files?  There goes my guess about compiling just one file. I should have thought twice about it.

At this point you are going further than I have ever been. I was used to, say, manually patch realtime extensions into a kernel version that wasn't the intended one (when realtime patches were still not merged into mainstream kernel). So automatically patching the source would fail, but one could find the right places to patch manually by just looking at the code. There was usually a whole bunch of files to patch, but it was quite an easy task that called for very little programming knowledge.

I'm into system administration, not programming. However, you are about to code/debug, etc, by yourself. You'll need to learn more about programming than I currently know. So take what I'm going to write with a grain of salt. Others in this forum will know about programming much better than me, perhaps they could help from this point forward.

I guess it could be done in eclipse and gdb, yes. But to learn about how the builds work, I would:a) learn about autotools, then b) look at the source code.

I think that would be the fastest way to learn. I have never, ever, used an IDE for any build. Software was built that way, much before anyone could heard anything about Eclipse. And Eclipse (I guess) will use the autotools infrastructure anyway.

Usually just getting in the upper directory of the source and using the configure/make/make install litany, would be enough. Makefiles do the magic. They will have the calls to gcc, with the different options, etc, so you don't need to call gcc manually for each file. 

Then I'm pretty sure that, by looking at source code and Makefiles, you'll find many, many clues. You'll have to dwell there for some time, I'm afraid, but again, quite probably that will be the fastest way to get the needed skills. The knowledge so achieved will be useful no matter which distro you are using, right now or in the future, debian-based, redhat-based, slackware, whatever.

After that, I think you could easily go with that knowledge to Eclipse and have a successful, quite fast transition to work with that IDE, should you still think you need it.

You are going to embark yourself into a quite interesting experience. I wish you good luck and lots of fun.

2

General Technical Chat / Re: The strange case of phase angles

« Last post by ballsystemlord on Today at 11:45:44 am »

simulate in Qspice

Learning Qspice is in my next book. But I could wait.

3

Buy/Sell/Wanted / FF Digilent CoolRunner-II CPLD Starter Board

« Last post by owiecc on Today at 11:43:11 am »

I have eight of these boards for giveaway. If you have a use for them just pay the shipping costs from DK.

https://digilent.com/reference/programmable-logic/coolrunner-ii/start

4

Projects, Designs, and Technical Stuff / Is this circuit adequate to interface a uC with a dc motor using an optocoupler?

« Last post by FBMinis on Today at 11:41:23 am »

I would like to make a device using an esp32c3 and an optocoupler to allow me to actuate a separate device comprised of a motor running from a different power source (4.2V, 6V or 12V).

The esp32c3 runs from 2x AA alkalines and would wake up periodically to run the motor for a minute, then go back to sleep.

What should I change in the attached circuit?

Thank you.

5

Beginners / Re: Blocking Phantom Power 48V from Audio output

« Last post by radiolistener on Today at 11:40:55 am »

How could I make the output blocking +48V phantom power?

What do you mean with "phantom power"?

6

Programming / Re: Linux Dependency Black Hole

« Last post by selvaklnc on Today at 11:35:43 am »

It's interesting to hear about your transition from using Linux in engineering to being a hobbyist in ham radio. Dependency issues can indeed be frustrating, especially as they seem to have become more prevalent in recent years.

One factor contributing to this escalation could be the increasing complexity of software and the rapid pace of development in the open-source community https://developer.wikimint.com/p/about.html#open-source. As projects evolve and grow, dependencies can become more numerous and interdependent, making it challenging to maintain compatibility across different versions and distributions.

One strategy to mitigate dependency issues is to leverage package managers effectively. Tools like apt, yum, or pacman can help manage dependencies and ensure that software installations proceed smoothly. Additionally, containerization technologies such as Docker can provide a more isolated environment for running applications, reducing the risk of conflicts.

Keeping your system updated regularly can also help prevent dependency-related headaches. By staying on top of software updates and package versions, you can ensure that your system remains compatible with the latest applications and libraries.

Overall, while dependency issues can be a nuisance, they're also a testament to the vibrant ecosystem of open-source software. Embracing tools and practices that streamline package management can help you navigate these challenges and continue to enjoy your Linux experience, whether in engineering or as a hobbyist in ham radio.

7

Beginners / Re: Why are thermal jumpers so expensive?

« Last post by Doctorandus_P on Today at 11:34:46 am »

I did a bit of poking before I posted, and did find AIN in high power SMT resistors, but was not sure about the "common" small resistors.

These higher power resistors also seem to be around 50ct, (or much more expensive for high accuracy ones) so similarly priced to these thermal jumpers.

8

RF, Microwave, Ham Radio / Re: High bandwidth FM signal generation

« Last post by radiolistener on Today at 11:33:56 am »

Cellular network operators do have the personnel and resources to find people jamming their networks - I worked with them for years - but most of the time this jamming is unintentional

if I understand correctly, for 5G it will be more easy than for 2G/3G/4G, because they using phased antenna array to rotate beam, so it will works like radar and allows to get more precise position of transmitter with triangulation, isn't it?

Just wonder is it possible to use some kind of synchronized array of transmitters distributed all around the base stations and transmitted signals in that way so their interference signal at base station location gives false position of the transmitter or just spamming it with a bunch of virtual transmitter positions to make it hard to find which one is real? Are such kind of jammers are used in practice?

9

FPGA / Re: Help on translate schematics to Verilog.

« Last post by caius on Today at 11:33:26 am »

[

If you use Quartus and have made a schematic, then while the schematic are selected you can click "File"/"Create/Update"/"Create HDL Design File from current file" (the schematic)  select verilog, give it a name, quartus will then make a verilog version of your schematic.

Thanks, I did it.I have these other two KiCad symbols that I'm try to identify, are they a D flip flop and a D latch with enable?Not sure though.

10

Buy/Sell/Wanted / Re: FS: Affordable DMM Checkers: AC Reference, DC Reference, OHMS Reference, etc.

« Last post by watchmaker on Today at 11:31:26 am »

[

If you limited the claimed to, for example, "...verify the function of 3.5 digit Digital Multimeters", then the points wouldn't even arise.

What you claim here (or "elsewhere") is irrelevant; what you claim in the advert is what matters.

This is basic measurement theory. While you need higher resolution than the manufactured reference to measure its calibration error, that same calibration reference can then be used on on lower resolution instruments (assuming it is stable).  If you only work in mA, you do not care what is going in pA.

So a lot depends on claims for where it should be used.  And the reliablity of the maker.

FWIW, I bought one of the current and voltage references from AliExpress.  It includes a sketchy paper claiming the actual values as measured by some reference down to the 7th decimal point.  Turns out these measurements were within a couple counts on my Fluke 45, Fluke 8842, HP 358a and Keysight 1252.

Have no idea why I bought it since all my instruments already agreed, but it was cheap and I am a measurement junkie (work down to 500 micro meters).