News from the embedded world

[WizardStan]

Is 4G considered to be a 'worldwide standard'?

No, the PLS8 also comes in -E and -US flavours with different frequency bands.

is there an ultra-cheap module that can be put in instead that just has GPS?

The PXS8 is pin compatible with the PHS8/PLS8 (and PVS8) and may be substantially cheaper (as it's only CDMA) but I can't find anywhere listing prices.

 

[mcobit]

I still think a gyroscope/tilt sensor would be nice.


This was never mentioned again though. Is it still plausible?

 

[Linux-SWAT]

Thx for the update ED !

About 2. UMTS and a hardware switch,

Is it possible that data are send in bursts too fast for the eye to ever see the led blinking ?

Anyway, at least, i hope for a destructive procedure, like cutting a trace (with space around to avoid cutting other things).

 

[comradekingu]

From how i read it, it wont be a problem, because you cant enable, transfer, and disable a 3g modem that fast. There are many commands to be sent, some of which take a little while for a start. If you will also be able to see data transfers i dont know, but i understood it as a always somewhat on LED when the chip is enabled.

 

[Linux-SWAT]

Mmm i'd prefer to be 100% sure.

 

[WizardStan]

It definitely takes at least a few seconds for system to find a cell tower. It won't be able to just blink on, burst some data, and turn off, but you might still miss the few seconds while it's on.

Wire the LED to a peizoelectric buzzer as well, just to be safe.

 

[Grench]

Mmm i'd prefer to be 100% sure.

So - instead of an LED, wire it to a GPIO that can record activity and/or launch an on-device event?

 

[_wb_]

@Grench: 3G is good enough for me -- I would use it to check emails and forums, Wikipedia and Google, low-bandwidth stuff. If I want to do high-bandwidth stuff I'll use wifi. Although 4G is available in most cities in my country, mobile internet costs 5-10 EUR per GB here. That means that if you can get real 4G speeds (~1 gigabit/s), it costs about $1 per second. Of course it will get cheaper over time, but still, that does not sound like something I would want to do even if it's 10 times as cheap.

I still think a gyroscope/tilt sensor would be nice.

Me too.

 

[slaeshjag]

Yes. As soon as a level change on that line is detected, the kernel will feed this into the DAC:

Spoiler

https://www.youtube.com/embed/y6pNoYZgWBs?feature=oembed

 

[WizardStan]

The reason for the hardwired LED is so software can't bypass your detection schemes. If you rig it back to the CPU to do something then you can still get malicious software somehow able to bypass those.

 

[Granitehead]

But seriously, hard wired LEDs is something for the tinfoil hat guys.
Make it possible to turn the module off for sure via software or make sure software (GPIO) is notified when it turns on if the former is impossible.

If you can't trust the OS to reliably turn on/off something or to notify you when it does so, then you are fucked anyway!

 

[WizardStan]

For some reason a hardware switch isn't possible, ok, fine. You could always just remove the SIM card if security is a problem. Tape it under the battery or something, swap it in when you want the data and remove it when you're done. That's your guarantee of security, or as much as is possible.

 

[Linux-SWAT]

Knowing that data can be transmitted without a simcard plugged in, the privacy problem isn't solved.

I really need a hardware kill method. Don't care if it's irreversible.

If the cut trace can be manually soldered back using strap copper points i'm fine with it.

 

[_wb_]

If you're very paranoid, don't get the 3G module.

If you're rather paranoid, remove the SIM card.

Otherwise just disable it in software.

I don't see the need for a LED. It's a redundant feature in my opinion. It will not be enough to make the very paranoid people believe they're safe, and it's overkill for people who trust their OS to actually disable something when they tell it to disable something.

If you can't trust your OS, then you shouldn't get the module, because you will never be able to use the module and feel safe anyway.

I don't really want my Pyra to look like a Christmas tree decorated with nicely colored blinkenlights everywhere.

ACHTUNG!

ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!

DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKEN.

IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.

ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.

 

[WizardStan]

Knowing that data can be transmitted without a simcard plugged in, the privacy problem isn't solved

Ok, I need to know how this works. How do you transmit data without a valid SIM card?

 

[_wb_]

Knowing that data can be transmitted without a simcard plugged in, the privacy problem isn't solved.

I really need a hardware kill method. Don't care if it's irreversible.

If the cut trace can be manually soldered back using strap copper points i'm fine with it.

The hardware kill method works as follows: you don't buy the module, it will not be present on your device, so it is very much killed very dead and buried exhaustively.

 

[mcobit]

What about a little dipswitch that kills power to the module right next to the simcardslot int he batterydepartment?


You could switch it with some pointy device like a screwdriver if you want. Those things can be very small.


Edit: Something like this:


http://thegioiic.com/media/BAhbBlsHOgZmIjUyMDEzLzA1LzI2LzIyXzMxXzA1Xzc2NF8xX3Bpbl9zbWRfZGlwX3N3aXRjaC5qcGc/1-pin-smd-dip-switch.jpg

 

[Linux-SWAT]

Ah ok, it's still a module ! Thought not.

@WizardStan, some phones can call emergency numbers even without simcards. I was told that in first aid courses three years ago.

 

[SNESFAN]

@wizardstan- your modem still contains your IMEI, your sim contains your subscriber information. IMEI is like a mac address, subscriber info is like your IP, you can make emergency calls without a sim so communication can still technically happen. The network will reject you without your subscriber informtion or unless you are making the emergency call. So it technically can transmit some type of communication without the SIM. Can that be exploited without some serious and I mean SERIOUS intervention? extremely freaking unlikely, you would need an inside with a service provider which I won't go into how that would be possible.

EDIT: midpost ninja

 

[slaeshjag]

All mobile phones can.

However, that's because all mobile networks allow calls to the emergency numbers without authenticating with your SIM. What they don't allow, is any other calls or data transfer without a by them accepted SIM.