jmpe

The URL sounded familiar... now I know why. ChaN is the person behind FatFs, an incredibly good embedded File System module. Currently using it on ChibiOS and very happy with it.

Legal situation?!? You're creating a matched impedance point in space.

RF energy harvesting is a bit of a hot topic, there are a number of modules on the market atm. Just search for it on mouser or farnell to get started.

Thanks btw for that LED schematic, so simple. I'm currently tuning a harvester around a BQ25504 and super caps. I'll give it a test next week.

http://uk.mouser.com/Embedded-Solutions/Energy-Harvesting-Mo...

This one contains other energy sources as well:

http://uk.farnell.com/jsp/search/browse.jsp?N=2002+225290&Nt...

I remember reading somewhere that this practice still exists today. That jets dump their payload in the sea before landing. As I recall it was a landing area in/around Italy during the Iraq conflict. Makes sense if you think about it, takeoff and landing are risky. Anyone care to chime in with some knowledge?

I'm mostly into hardware, these two provide me with top content:

Ben Krasnow, physics for the underfunded:

http://youtube.com/user/bkraz333

Ham Radio Now, lots of SDR talk and good content:

http://youtube.com/user/HamRadioNow

I have many others (e.g. CCC), but on mobile inside an observatory atm.

Found this little tidbit while reading an article about the Cal. drought.

Additional info on the Sensor network SNOTEL:

http://en.wikipedia.org/wiki/SNOTEL

And meteor burst communication:

http://en.wikipedia.org/wiki/Meteor_scatter

I changed the title to "Can [it be done]" because the article's title states it as fact even though its effectiveness is questioned. I'm aware that this deviates from HN guidelines but I don't want to submit clickbait.

You're seriously underestimating this issue.

- rabbits/cane toads in Australia [0][1]

- Japanese knotweed [2]

- Tumbleweed (yep, not as native as Hollywood suggests) [3]

- Algae [4]

... and the list goes on and on, here's a top-100:

http://en.wikipedia.org/wiki/List_of_the_world%27s_100_worst...

[0] http://www.youtube.com/watch?v=pgPhn4tYxJQ

[1] http://en.wikipedia.org/wiki/Cane_toads_in_Australia

[2] http://www.environment-agency.gov.uk/homeandleisure/wildlife...

[3] http://en.wikipedia.org/wiki/Kali_tragus

[4] http://plants.ifas.ufl.edu/node/89

That makes sense.

But regarding your last sentence: I'm not very fond of that risk analysis. Potentially introducing an alien aquatic micro-organism (that's what we hope to bring back, remember) into earth's system... No competition, paradise compared to its hostile home. No meteorite has ever been shown to carry life, but into this case we intend to deliberately introduce it, either controlled or uncontrolled.

NASA can bill me for the extra cost for taking it to ISS instead of earth's surface.

"Dr. Tsou devised a way to capture comet particles and bring them back to Earth for NASA’s Stardust mission and has been suggesting a similar method for a spacecraft that would fly through Enceladus’ plumes and then return to Earth for scientists to examine.

The challenges are to make sure that the interesting particles would not break apart, to take precautions that any alien life would not infect Earth, and to fit it into the $500 million budget of one of NASA’s lower-cost planetary missions."

Why bring it back to earth? Wouldn't it be safer & less expensive to return it to ISS instead, (or is that what's implied) ?

Didn't know the carbon & nitrogen part of the story, read the article thinking only 1 thing: "when are you going to mention Europa".

Not really off-topic: at 42:00 the setup shows a Novena prototype. They used a binder as case.

The CCC backside attack is here:

https://www.youtube.com/watch?v=dtviiOJ-2hI

It contains lots of info and technical details.

Another one:

https://www.youtube.com/watch?v=KVmpBPbGPsQ

This is what an actual ROM looks like:

https://docs.google.com/document/d/18IGx18NQY_Q1PJVZ-bHywao9...

As the last image shows, the ROM table values are extracted by graphics processing the photo.

It's also possible to dump the ROM by reading it byte by byte, but this depends on the architecture (not always possible) and is typically done for mask ROMs that contain data.

Currently on mobile, will update tomorrow.

Start here:

http://www.visual6502.org/

Somewhere in that site they detail the step by step process of decapping, delayering photographing and identifying the logic.

There's also a JavaScript simulator, check it out.

The CCC also had a few lectures about decapping. The most interesting one is about backside scanning the die to bypass the safety features.

In you want more:

http://zeptobars.ru/en/

The nice thing is they decap old/common devices.

A lot of these places will hopefully not become tourist attractions, they exist because of - not despite of - lack of human activity.

Notice they use the GigaFLOPs metric, which is a (maximum) floating point measure. Bitcoin hashing (it's been a while for me) is compute intensive on integer math. For a good ratio of performance/power you'd want to look at architectures like the GreenArray devices. But the world of bitcoin hashing is now firmly positioned in ASICs. You can't cut architecture fat beyond that so you'd have to look at (general purpose) architectures built on a faster silicon technology. Wouldn't count on it.

http://www.greenarraychips.com

The author should look into DTMF, they were quite popular in packet radio and you got a 1200 baud datarate. Haar Wavelet transform would probably be a lot less CPU-hungry than FFT.

http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signa...

Studies have shown that the most effective measure is to switch everything on, dropping the termination impedance, whilst taking production partly offline.

I have a couple of links at the office, currently at home.

The link is the same as the one Google takes me to, but apparently they check the referrer. If you come from Google: no paywall.

There are PCB design/layout rules that deal with BGA. I'm not saying it's a 100% guarantee, but (much like EMC/EMI design rules) there are a lot of solid pointers that remove 90% of the issues. The remaining 10% are (again, much like EMC/EMI) subject to the layouter's level of experience.

Currently on mobile, can't link a PDF right now but if you Google " BGA PCB layout guidelines" you'll get a ton of documents.

Lastly: PCBs go through several optimization cycles, some occur after release for high volume stuff. There are always revision numbers of the silkscreen, sometimes they catch an issue like this after x1000 devices in the wild and do an update.

This sounds like a BGA issue. They also had the on PS3/4 and XBox if I'm not mistaking.

The chip has a grid of small solder balls on the bottom instead of pins sticking out. Due to thermal differences during operation some rows can experience mechanical stress due to uneven heating of the device. When there are cracks the contact disconnects from the board. Some images here:

http://www.playbackups.com/Playstation3-xbox-360-repair-repa...

When it's cooled again the contacts join, placing it in the oven applies an even thermal load across the entire board and you basically anneal the cracks.

Wildly?

When you develop software based on your own novel framework, wouldn't you need to do several test-runs, performance runs, sanity runs in the process? Do you keep all the intermediate debug data? I know I don't. In this case bitcoins would be part of the intermediate data.

Check out "The Scientific American Book Of Projects For The Amateur Scientist" - C. L. Strong describes quite a bit of this in the section "The earth sciences". The schematics date from 1960 (tubes, not transistors) but you'll find updates around the web.

http://www.sciencemadness.org/library/books/projects_for_the...

Notice that they explicitly mention IoT, a week after Atmel announced a similar controller for an IoT module:

http://atmelcorporation.wordpress.com/2014/02/24/atmels-smar...

Get yourself a discovery board from ST, same architecture (actually: a good range of choice) and no need to solder a 3 mm2 BGA ;)

an RTOS (uC/OS, Freertos, chibios, ...) or simply a hal such as CMSIS.

For more info on this search for "defensive programming", "Immunity-aware programming" and "preventitive programming". Several hardware companies have manuals/rules for programming in harsh environments.

Even if you're not into hardware it's worth a look, lots of cool tips.

Here's a video where the author describes the work in the paper:

http://youtube.com/watch?v=fpZD_3D8_WQ

Very accessible.

   For more technical searches, Google has become next to useless for me.

Same here. I used to have corrections for java -> javascript but that seems to have been fixed.

Just this morning I tried searching for this:

   µC/gui button detach

... "detach" gets corrected to "remove" and "disconnect", resulting in useless links. The top 2 links are general features overview pages.

Which is odd, because googling this:

   button detach

results in lots of uncorrected queries for event delegation. You'd think that adding "µC/gui" would narrow the context, but no.

They used bait & switch in Europe (at least where I was) to entice SMS adoption. There was a multitude of free SMS services: online sites where you could send someone a message for free or SMS a service that would forward it without being charged. Then, in the span of a few weeks, the services disappeared.

Embedded means bare metal access to everything. An OS like Linux shields such functionality, which is why it's frustrating to implement something as simple as a triac dimmer in a Linux SoC without doing everything in kernelspace to avoid kernel jitter and event delays.

Embedded systems typically run on a microcontroller. It almost literally means something that reads an input from the physical world (EXTI, logic level or adc) and uses it to control something. Microprocessors typically implement a bus system and additional units like an MMU. We used to have uC with basic busses, but that was for different reasons (EPROM, LCD, ...)

These days the word embedded seems to mean "fits in a small box".