Rick's b.log - 2017/09/03
You are 18.118.152.12, pleased to meet you!
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Rick's b.log - 2017/09/03 |
| It is the 18th of December 2024 You are 18.118.152.12, pleased to meet you! |
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mailto: blog -at- heyrick -dot- eu
This is also the week that the British raised a great hue and cry over the horrible mistreatment of the Brexit process by the European Union. You know, the bit where the EU said repeatedly that:
Sadly, an opinion peace in the Aussie paper AFP (Australian Financial Review) is following the British delusion with an article on how the EU is giving the UK the runaround. I guess this is what happens when you have journos on the other side of the planet who are every bit as cluelessly idiotic as the current British government. I won't give you a link - the article is quickly replaced with a paywall, it takes fiddling with the webdev console to get at the content before it vanishes. It's afr.com, go Google if you're bored enough.
And, so, it's a half year after article fifty, nearly a year and a quarter since the referendum, and still we citizens on either side of the problem have no real idea what is going to happen next.
May, David, Boris, Farage... Please, just die. Then maybe somebody can try to salvage the mess that you have created before the history of the United Kingdom becomes nothing more than a side note in other people's history books. "They were great once", like we think of the Romans or the ancient Greeks...
With this in mind, I have ordered a replacement from BangGood. It is basically a revision of the same device, more surface mount parts and a new UI with a rotary switch to make things easier. Even so, it is still based upon the STM32 microcontroller so it tops out at 150-200kHz (triggering at a maximum rate of 10µS/div), and this time it seems capable of going up to 20V/div which ought to make it capable of 160V swings (eight divisions vertically) but it is limited to a maximum of 50V input. That said, I think 12V is the most I've ever tried to measure, with 1.5V-5V being the norm.
To give an idea of the sort of accuracy that one obtains from the DSO138 (and likely the Shell as it is the same chip inside), here is a look at a PAL composite video waveform:
That said, while you cannot determine the specifics of the PAL CVBS signal using an oscilloscope that claims 200kHz, it is sufficient to tell that it is indeed a PAL signal. Likewise I have used it to work out the baud rate of a serial signal from the timing, as shown above. I also did an article on decoding an IR controller's signal. For these lower speed things, the oscilloscope functions perfectly well.
Oh, and speaking of Amazon, I put up a review to point out that while the kit worked, it was very much a fake:
What concerns me is that young children are trying to work out their identity - who and what they are - and they are going to get stuck with the possibility of weird emotional baggage inherited by adults that never worked out their own identities...
Brexit
Last week, Theresa May laid into "the unacceptable face of capitalism". That's a mighty fine rant for somebody who is trying to keep cosy with Donald Trump. Maybe May ought to look up the definition of the word "capitalism" in the dictionary of her choice? It'll explain why a "good deal with America" will be good for the Americans. For her? Not so much.
where to be negotiated to satisfaction before any other part of the negotiation takes place. Mr. Barnier of the EU even went as far as to respond to Boris' "go whistle" comment with his own comment that he hears no whistling, only the sound of a ticking clock.
So it's now half a year since article 50 was invoked, a quarter of the entire negotiation time has passed, with the British government still releasing "position papers" which have enough holes to drive a truck through. The EU is right not to trust her - remember, this is the government that "accidentally" sent letters to a hundred EU nationals living in the UK telling them to pack up and get out (later called "a mistake", just like the money for the NHS or the immigration figures). This is the government that seems to be unconcerned with the treatment of foreigners by the less polite members of society.
So, three simple things to be sorted out first. May, Davis, et al have basically wasted a quarter of the ridiculously short negotiation time and now they're screaming about how the unfair EU is refusing to discuss trade in parallel. There is a point when belligerence is just stupidity.
Do they not understand what "first" means? You know - first, as in "America First! America First! America First!".
JYE Shell
I have not used my oscilloscope much, as I don't do a lot of electronics work. When you know how to read the display, the times when I have used it, it has been invaluable, such as here - to verify that a signal was present, to observe it as a serial data stream, and to use the timing to work out the baud rate:
As you can see from the picture (a composite of the pictures at jye.com), the LCD is attached to the main board with a ribbon (thank god I don't have to make those 80 solder joints a second time!) and the increased use of surface mount means the component count has been reduced. This should be an easier kit to build. The case looks more rugged than my perspex case for the DSO138, however JYE missed a trick here leaving the thing with a socket for a 9V input. With a little LiPo battery, charger circuit, and DC-DC convertor... or even a hole for a bog-standard PP3 cell, this could have been a great little portable oscilloscope for simpler low frequency measurements. The price of the entire kit from BangGood runs to around $20 (with free postage) and it is a genuine JYE kit, so it is even cheaper than the (fake!) DSO 138 kit on Amazon. And if you're up for a challenge, the DSO 138 itself is discounted right now on BangGood, they're practically giving it away. I didn't pick up a second because... yuck... soldering the connector for the LCD is not something I'd enjoy repeating. Yay for the Shell having it pre-attached with a ribbon cable.
You can clearly see the "outline" of a PAL CVBS waveform for a single scan line, however as can be clearly seen by the rounded sync pulse and the apparent lack of colour burst in the back porch, the oscilloscope struggles with waveforms where the elements are measured in such short durations as 1.65µS.
To put this into context, here is the exact same signal as displayed on a traditional CRT oscilloscope set to the exact same settings (0.5V/sec, 10µS/div):
Or, to directly compare:
And, it cannot be stressed enough - a "proper" cathode ray or high frequency digital oscilloscope costs €€€ even second hand. The DSO168 kit is somewhere between €13-€20 on BangGood (and approx twice that on Amazon.fr and likely a fake); the DSO Shell is currently marked down from €25 to €18. It is extremely cheap, and it is based around a high speed ADC built into an STM32F103C8 microcontroller (ARM Cortex-M3 at 72MHz, 64K Flash, 20K SRAM; 12 bit 1µS ADC). It's impressive what it has been able to do, but we ought to recognise its limitations. After all, a BBC Micro can't play MP3s, can it? Neither can this oscilloscope show the 2MHz clock signals inside said Beeb.
Plus, it's just fun to put a kit such as this together...
Gender neutrality
So I hear that John Lewis are labelling children's clothing "For boys and girls". Excuse me, but what the hell is this gender neutrality bollocks? I can understand that jobs can be gender neutral - a woman is running the UK and a man is running America, thus demonstrating that stupidity is not gender biased. I can even understand that toys being sectioned into "pink stuff for girls" is a bit naff. A boy might like to play with a doll and a girl might like to play with a Scalextric - and there's no real reason why they shouldn't. But don't you think it is a bit far labelling dresses as for boys as well as girls? People themselves are not "gender neutral" no matter what any asinine campaigners may say - a quick trip to the maternity unit of any hospital on the planet will make it quite clear that girls and boys are in fact different. Biologically different. They can do the same things, boys can cook and girls can go shoot bad guys (to pick on two heavily stereotyped roles) but only females have breasts that work and the ability to give birth. And the last I was aware, menstruation was also something that didn't happen to males. Maybe it ought to be renamed "womenstruation" as it seems some people have difficulty with this whole boy-girl thing.
And coming soon...
Over the summer holiday and various evenings, I've been working on a little something. Here's a teaser for you to ponder:
PS: Yes, that's me.
GAVIN WRAITH, 4th September 2017, 17:37
The PC boys and girls nonsense is interesting. Thirty five years ago our two girls were roped in for some kind of experiment at Sussex University to measure gender-stereotyping. To our shame both girls made a beeline for the My Little Ponies, and shunned the diggers and trucks on offer. And our grandson, 3 and a half, is mad on diggers and trucks; anything with wheels. Let nature take its way - well you don't actually have much choice about it, anyway.
Recognized you immediately from your photo!
You know that this masculin/feminin business in Indo-European languages is only a relatively recent development? 4000 years ago the distinction was animate/inanimate or (it-can-fight-back / passive).
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