I don't recall. I've slept since then. It's definitely called a Rocket Board. I'm looking at the box on the shelf and there's a cute little rocket on the side. Too lazy to get up to look in the box.
John
It's getting very difficult to even get surface mount ICs these days too !
I'm glad you mentioned that. I had noticed that it existed but hadn't realised just how nice it is! I've just ordered a few to have a play with. I assume the lack of hard real-time comes from execution out of flash memory? The i/o state machines should give hard real-time though.
John
On a sunny day (Fri, 26 Feb 2021 02:04:10 -0800 (PST)) it happened John Walliker wrote in :
A warning I have decided to stop with raspberry stuff as when I got the RPI4 8GB and they released their own Linux OS version it sucked. They are now bringing out one thing after the other and looking at their datasheet for the pico I wonder if it is worth anything. Maybe it is freedom expected when leaving the EU that made them like to do something totally different. And how long will it be supported, and will an other version appear next monday. It has an on board ADC it seems but the reference sucks. ARM no ARM, maybe better use a PIC, long time support is good for Microchip Even a 3 $ PIC has multi channel ADC and good internal reference. Else for logic use a cheap FPGA board perhaps.
RT support is independent of the storage media from which opcodes are fetched; the media has predictable performance levels so it falls out of the equation.
But, the hosting OS needs to be designed with RT in mind. This affects scheduling decisions, resource allocation strategies, "priority" assignment, etc.
Sadly, HRT is often confused with "real fast"; that's not the driving criteria. Likewise, associated with "having significant consequences for missed deadlines".
There are lots of HRT tasks that aren't fast, have LONG deadlines (with relatively low computational burdens), etc. And, many whose consequences of a missed deadline are just a shrug.
A first-order approach to designing for HRT is: when the deadline for a task comes, kill the task (if it hasn't met its deadline, there's NO POINT in continuing)!
By contrast, SRT suggests you keep working on tasks that miss their deadlines as there is still some "value" to be had in their completion, even if "late".
And, of course, any task WITHOUT a deadline is simply not RT!
:>
Anything with caches or interrupts makes it difficult to guarantee timing, as does multiplexing/timeslicing multiple threads onto a single core.
Much easier if you have enough decent cores (i.e. ARM level not LUT level!), inter-core hardware for comms, and - most importantly and rarely - a decent parallel processing concept and tools.
The XMOS xCORE devices have up to 32 core, 4000MIPS per chip (expandable), an IDE that tells you the exact number of cycles it takes to get from here to there[1], and the xC language based on parallel processing, messaging, and avoidance of C features that makes multiprocessing "error prone".
It has a solid theoretical and industrial pedigree: Hoare's Communicating Sequential Processes from the 70s, then the Transputer and Occam from the 80s, and quite a few concepts seen in other modern languages like Rust and Go. XMOS has been doing this since, I believe, 2007, and you buy the parts at DigiKey etc.
It can, for example, use /software/ to input/output and process a 100Mb/s ethernet serial bitstream. (Whether that is a sensible use of silicon is a separate matter; what's important is that it can be guaranteed at all!)
[1] i.e. no such it and see and hope you stumbled across the worst case
No, it really is (for me at any rate). My unquenchable thirst for knowledge led me to goof around with liquid mercury for a while when I was young. I became quite infatuated with the stuff and the way it formed amalgams with other metals such as silver and the properties of those almalgams. Anyway, to cut a long story short, this obsession resulted in my developing Parkinson's like tremors from a very young age which I've never recovered from. So I'll be giving the tweezers a miss, I'm afraid. They really wouldn't help.
True, but my interest lies in more fundamental pursuits. To take an analogy from computing, people like yourself work in high-level langugages and get a lot done in short order by using powerful and complex chips. That doesn't appeal to me at all. I like assembly language and machine code. It takes reams of code to get anything done, but you get total control over everything and need to understand every single aspect of what you're building, right down to the finest details. THAT is what *I* get off on.
--
"Andrey Semyonovitch really was rather stupid; he attached himself to the progressive cause and 'our younger generation' from enthusiasm. He was one of the numerous and varied legion of dullards, of half-animate abortions, conceited, half-educated coxcombs who attach themselves to the idea most in fashion, only to vulgarise it and who caricature every cause they serve, however sincerely."
- Fyodor Dostoevsky
Mercury poisoning? How unpleasant.
Are you aware of having any of the other traditional symptoms?
I very seriously doubt there is any connection between your Parkinson and elemental mercury. Mercury is not absorbed through the skin and at ambient temperature, the vapor pressure is so low as to be negligible. Organic mercury compounds are a whole different matter
When I was a teenager I suffered acute mercury poisoning. I had collected about 30 lbs of dirty mercury. Mercury is normally triple distilled before use. I welded up a mercury still. It had a leak.
I operated it in a tiny half bathroom. I didn't realize it was leaking until I saw little mercury droplets collecting on the walls. The next day I was extremely sick with flu-like symptoms. I told the doctor what I had been doing, he did a heavy metal test and sure enough I had a large amount of elemental mercury in my blood..
Several chelation therapy* treatments later, my mercury level was back to below detectable.
*a chelating agent is an organic molecule that bonds to and encapsulates the offending metal atom in a form that will pass through the kidneys.For over 20 years I've made neon signs and art as a hobby/casual second business. Neon uses mercury. If I spill some, I pay it no mind. There are droplets of mercury on my bombarding table. Yet my bi-annual test for heavy metals including uranium come back below detectable.
Just to check current knowledge, I just googled. Over 4 pages of results, not one credible source made any connection between Parkinson's and mercury. Of course there were pages of mecuriphobes and fraudulent huxters. and frauds but nothing authorities. One of my authorities sources is the Mayo Clinic. I searched for "mercury and Parkinson's" and got no results.
BTW, if you want to see something spectacular, take a flat piece of aluminum, place a drop of mercury on it, then reach through the puddle with a tool and scratch the aluminum to remove the oxide layer. Mercury loves to amalgamate with aluminum. The amalgam grows out of the puddle as the mercury consumes an amazingly large amount of aluminum. An aluminum casting is best for this in ordrer to provide enough aluminum to consume all the mercury..
John
They certainly are. Dimethyl Mercury springs to mind as a prime example. It's extraordinary the toxicity increase obtained by the addition of just a couple of CH3 groups. I recall some lady doctor - an expert in heavy metal poisoning - accidentally poisoned herself one day working with Hg(CH3)2. A single droplet landed on her gloved hand (surgical gloves of whatever material). She knew she had to whip off the glove and thoroughly wash her hand within 20 seconds. She didn't quite make it in time. Slowly lost her mind over a period of a year and died in agony suffering horrific halucinations. It's like working with deadly snakes, that stuff. It can happen to the best of us; a momentary lapse of concentration and you get stung. :(
Yes indeed. There's a video on Youtube of it somewhere I've seen IIRC.
I don't think it's helpful to search for "parkinsons & mercury poisoning" as the key symptom was tremor of the *kind* seen in Parkinson's. I didn't say it brought on early-onset Parkinson's. Neverless, I take some comfort from your reassurances, given your own 'saturation exposure' to the metal. :)
--
"Andrey Semyonovitch really was rather stupid; he attached himself to the progressive cause and 'our younger generation' from enthusiasm. He was one of the numerous and varied legion of dullards, of half-animate abortions, conceited, half-educated coxcombs who attach themselves to the idea most in fashion, only to vulgarise it and who caricature every cause they serve, however sincerely."
- Fyodor Dostoevsky
I f
I'm sure I did that experiment back when I was in school/college ~60 years ago. It also explains the otherwise strange prohibition of mercury thermometers (or anything else with Hg) on aircraft...
Raspberry Pi OS was just a name change for Raspbian which is the OS they have released since the first Raspberry Pi. It is essentially Debian!
On a sunny day (Sun, 28 Feb 2021 15:44:43 -0000 (UTC)) it happened Jim Jackson wrote in :
More or less. I have a sdcard that runs fine in the Pi4 4GB RAM. Many month of work and coding in it. Would you expect to run it in a Pi4 8GB? No it does not, they changed for example the boot code. Brexit gone to their head/ Would you like a PC that had 4GB RAM and you upgraded to a 8GB memory version and nothing would run on it? And they changed the audio system in there raspi OS so it is now incompatible with all the old code.
I have seen so much linux shit over the years, starting with rathead incompatible libc then oss replaced by inferior alsa, then dbus, now alsa replaced by whatever it is on the raspi OS No it is not debian (anymore). Xfree was an other thing that got screwed too.
Less. Cut down version. Works though! --
"Andrey Semyonovitch really was rather stupid; he attached himself to the progressive cause and 'our younger generation' from enthusiasm. He was one of the numerous and varied legion of dullards, of half-animate abortions, conceited, half-educated coxcombs who attach themselves to the idea most in fashion, only to vulgarise it and who caricature every cause they serve, however sincerely."
- Fyodor Dostoevsky
Jan Panteltje wrote in news:s1gfaf$3ch$ snipped-for-privacy@gioia.aioe.org:
Does it have to do with the new systemd stuff?
On a sunny day (Sun, 28 Feb 2021 17:33:10 +0000 (UTC)) it happened snipped-for-privacy@decadence.org wrote in :
Yes systemd is an other thing that changed over time.
The not booing of SDcards for the Pi4 4 GB in the Pi4 8GB version has to do with differences in the boot EEPROM code in the 8GB version.
Yes. But only if I did an OS upgrade. It has been that way from the beginning. If you do the apt-get update && apt-get upgrade on the 4G Pi, then the SD card will work in the 8G card. I've done that going from Pi1 to Pi3 then when I went to Pi4.
Are you refering to the shift to Pulseaudio? I find that just installing apulse (a wrapper that makes programs use plain ALSA as if it were pulseaudio) and removing pulseaudio works fine.
Debian has pulseaudio (dunno if it is installed by default - suspect it is) Debian certainly doesn't OSS anymore, it uses ALSA and/or PA. There is an OSS compatability kernel module for ALSA, so programs that expect OSS still work - and it works on my OSS programs.
Xfree got arsy with their licensing, so it was forked from the last version with proper free licensing. So Xorg is xfree but under a different anme and a different set of developers, and is used by every linux distro out there.
If you are so pissed by this, why do you still use this stuff - go use windows or a MAC or something? You sound like you are just a whinger.
That's pretty gorgeous. That color blue is fantastic.
Between that, a CNC and a flatbed CMYW UV printer a lot of pretty boxes would be possible.
-- Best regards, Spehro Pefhany
Jan Panteltje wrote in news:s1glbs$rvs$ snipped-for-privacy@gioia.aioe.org:
Get a hummingbird instead. More expensive but more professional too.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.