Recent Posts

1

Microcontrollers / Has anyone used ASAN & MSAN, and relevance to embedded arm32

« Last post by peter-h on Today at 01:57:22 pm »

This came up on the MbedTLS mailing list, where somebody had some weird bug.

A suggestion was running the code with Asan
(https://github.com/google/sanitizers/wiki/AddressSanitizer) and Msan
(https://github.com/google/sanitizers/wiki/MemorySanitizer), both
natively available on Ubuntu.

But doesn't this require building the code for a "PC"?

In the case of MbedTLS one can indeed build a win32 version (and I do have that, done by the guy who did my MbedTLS implementation) although this was quite a lot of work, especially to use the same memory allocation strategy as the embedded target uses, which is quite important since you are processing external data (certificates of various sizes and with different hashes etc).

In my case I do not use the heap other than a one-off malloc for an optional feature which is never freed so fragmentation is impossible.

2

Repair / Re: Rigol DP712 Output Shorted; Fuse? / I Screwed Up

« Last post by shapirus on Today at 01:56:03 pm »

It's interesting. What's the rationale behind using a thyristor for something as simple as discharging the output cap? Why don't they use a resistor instead of it?

3

Security / Re: Microsoft repackages apps with a telemetry .NET wrapper

« Last post by Marco on Today at 01:52:37 pm »

Microsoft forcing telemetry on you is 'getting your panties in a twist'? That only seems innocuous compared to them not limiting it to the Store.

Could be worse, they could insert an online certificate check into your application (even though a certificate revocation list is easily possible and inherently superior for both privacy and security).

4

Beginners / Re: Automatic golf ball dispenser

« Last post by soldar on Today at 01:51:39 pm »

LOL...

1. don't HATE, Never hate, it's a bad habit.
One thing i've learned in 50 years is we have so many people in this world and they all have many different personalities and each
have their own psychologies that are associated with them. As humans we can only get along with people who have the same or similar
psychologies as our own, which ultimately means you cannot get along with everyone.. EVER !!!

that being the case, If you hate because someone did something that you didn't agree with (According to your psychology) then you are fighting a losing battle my friend and will do nothing but frustrate yourself and cause yourself health issues later in life.

2. But did it ever occur to you that there were other reasons why people suggest he use a micro ?
YOU ARE CORRECT... It's not necessary. But this person came to us with a very simple problem, but a problem that wasn't simple for him.
as tech people we want to help him AND GIVE HIM IDEAS and even though not necessary now, the introduction
of a dev board now is going to lead him down different paths of possibility that will either help him solve his problem or cause him to think in different directions and help him down the track, or perhaps he has this underlying idea that he didn't bother to mention that does actually require a dev board but now that it was mentioned, becomes a possibility

Mate, it's called  BRAIN STORMING,  it doesn't have to make sense or be necessary at first.
and if he's never used an arduino, and given his curiosity  HE SHOULD LEARN HOW TO USE ONE

Just like a person who has never used a hammer should go out and find nails to pound into timber if for nothing else but the experience.
This project may start as an arduino project, then he'll encounter issues on V 1.0 , then he'll refine it and perhaps on v 6.0 it turns out being
what you said and has nothing to do with arduino.. BUT HE GAINED EXPERIENCE FROM IT that would help him in later projects.

Never hate, it's not productive to anyone

Are you on some spectrum or something? 

You sound like the kind of person who,  at a social gathering, when someone says "I hate it when the toast falls to the floor with the jam side down" would go on to a speech about how hate is so negative and you should make the toast on the floor a positive experience.

And when, in an attempt to get away, they ask you what the time is, you would try to teach them how to make a clock ... which is always a useful skill.

The OP is interested in playing golf, not in learning Arduino.

Look, I am beginning to learn Arduino myself; I think it is useful and entertaining... for me. I do not try to shove my own things down other people's throats because I do not want golfers telling me how great golf is.  And any golfer who tries to talk me into golf, their religion or any other cult, like Linux or Apple, I am going to walk away from. Microcontroller guys can be as bad as other types of fanatics.

5

Repair / Re: Rigol DP712 Output Shorted; Fuse? / I Screwed Up

« Last post by IanJ on Today at 01:51:21 pm »

I can't understand only the function of p-channel MOSFET.

Hmmm, possibly when the thyristor turns on the mosfet will turn on also so that when the output cap is discharged it will also pull/reference the neg output down to earth via the mosfet, i.e. stop any spikes when the thyristor turns on.......if the other end of the 390ohm is tied to earth.

Just a thought.

Ian.

6

FPGA / Re: Help on translate schematics to Verilog.

« Last post by caius on Today at 01:42:48 pm »

> I have these other two KiCad symbols that I'm try to identify,

If you have KiCAD schematic file you can fetch type of symbol from it. Just open it in KiCAD, select symbol and press 'E'.

Thanks for reply.I just need the Verilog modules of the two gates to be implemented as symbols in my Quartus schematics.No ned to be FPGA compliant (well, I'm going to use MAX7000S CPLDs)

7

General Technical Chat / Re: Why don't we make [more] use of water wheels?

« Last post by coppice on Today at 01:41:19 pm »

I have spent the last few weeks roaming about in France and in Provence I saw many waterwheels but none in use. Originally they elevated water or provided motive power for mills or factories. None are in practical use any more. They are kept only as tourist attractions.  Since the wheels and water canals are already there you could think they could be easily adapted to generating electrical power but it looks like it just isn't worth it.

I think you'll find plenty of water wheels preserved as museum pieces all over Europe. There are certainly many in the UK. They can't really be both museum pieces and effective modern power generation platforms. As they stand, their high cost of maintenance is justified as a running cost of the museum. If they have to stand on their own merit, maintenance costs could only be justified if the place is far from the madding crowd, and does not have economic access to grid power.

8

FPGA / Re: Help on translate schematics to Verilog.

« Last post by caius on Today at 01:40:45 pm »

> I have these other two KiCad symbols that I'm try to identify,

If you have KiCAD schematic file you can fetch type of symbol from it. Just open it in KiCAD, select symbol and press 'E'.

No, unfortunately I have a PDF of schematics but not the source.

9

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

« Last post by Saimoun on Today at 01:33:52 pm »

What do you mean with "phantom power"?

Like the 48V that an audio mixer can send over an XLR cable for example. As I understood it is typically raising the DC voltage from 0 to +48V on both pins 2 and 3 through a 6.8k resistor.

However you need to double the capacity of the 22uF to 47uF or something like that, because capacitors in series act the same as resistors in parallel.

Very good point I did not think about that! Actually what about the discharge - would that not damage the first cap and/or the opamp behind it?

10

FPGA / Re: Help on translate schematics to Verilog.

« Last post by xvr on Today at 01:32:48 pm »

> I have these other two KiCad symbols that I'm try to identify,

If you have KiCAD schematic file you can fetch type of symbol from it. Just open it in KiCAD, select symbol and press 'E'.