

Smartphone EMF Detector - epicjefferson
http://ledhack.org/smartphone-emf-detector/

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minikites
> but we still do not know how the signals affect our bodies

Actually we do and we know that they do not affect our bodies.

~~~
_pmf_
> Actually we do and we know that they do not affect our bodies.

I have some of that healthy radioactive toothpaste from the 60s laying around
that you might be interested in.

~~~
mikeash
I hope this is just supposed to be a generalized point about how risks aren't
always understood immediately, and not an attempt to equate low-frequently RF
emissions with radioactivity.

~~~
marincounty
They are still not Completely sure EMF's don't cause health effects. I'm not
going to get into a debate, but even government literature uses sentences, and
paragraphs like, "continues to point to the same weak association.", or "At
present, the weight of the current scientific evidence has not conclusively
linked cell phone use with any adverse health problems, though scientists
admit that more research is needed."

So, right now I don't chastise anyone if they are concerned. I'm not a heavy
cell phone user, but a family member is--and when she was concerned, I didn't
feel like a alarmist when I agreed she should use get used to using the
speaker.

As to living near a step down pot transformer; it would be in the back of my
mind when buying a house. Yes--I know what the research showed, but the only
two PG&E workers, I knew, died of leukemia.

I know one Doctor(Dr. Dustin Ballard, Marinij.com), who reluctantly told his
readers that even though the the studies show no link between cell phone use
and cancer; he had two patients, whom were heavy cell phone uses, develope
brain cancer. He's not a quack, but just wanted to pass along the information.
He implicitly stated, 'I'm not saying cell phone use causes cancer!'

PG&E used to have a one page warning about EMF's. They used phrases like the
government does--like "most likely", 'and all research points to their safety,
but if one is concerned buy a gaussmeter.' I currently, can't find the PG&E
page, but it there.

So when I read National Institue of health webpages, and they still use
"like", "haven't been conclusively proven", "more research is needed."; I
don't feel comfortable telling people their concerns are not valid. As to a
guass meter, I use my portable radio, and check for static.(No--I'm not
running around and checking every possible emf, but I am checking the ones
near my head when sleeping.

(Way off topic, but if you have a mechanical watch that's not keeping time run
it through a demagnetizer before shipping it off for en expensive Service.)

[http://www.niehs.nih.gov/health/topics/agents/emf/](http://www.niehs.nih.gov/health/topics/agents/emf/)

~~~
minikites
[https://www.youtube.com/watch?v=uJ3ea9fa6CA](https://www.youtube.com/watch?v=uJ3ea9fa6CA)

"A huge amount of study into whether these microwaves cause cancer indicates
that they probably do not, and the World Health Organization classifies them
in the 'Needs more study' category along with coffee and pickled vegetables."

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mbell
Given that the frequency response of this is probably << 5khz I would guess
most of the EMI being picked up is from the inductors in the phone's voltage
regulators, not RF transmission.

I also I assume the minimum threshold is set fairly high given the shape and
location of the antenna. Arduinos and USB links, especially from laptops, are
rather noisy themselves.

~~~
rsync
Well, a decent way to differentiate these would be to put the phone in
airplane mode, and then you'd see what RF was significant and not.

And then after that, a further level of differentiation would be to take the
phone _out_ of airplane mode, but remove the SIM card.

I feel like those different states would be worth comparing...

~~~
mortenlarsen
I agree, that would be interesting. Removing the SIM would not prevent the
phone from communicating using GSM (emergency services, should still work).
But I guess it would probably prevent data (EDGE, 3G, 4G etc.) from being
active. Also I guess the internal processor in the SIM is fairly low frequency
(5 MHz I think) so the detector will probably be more sensitive to this than
it is to the internal CPU in the phone.

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stephengillie
This is a neat little EMF detector. I love seeing Android hobbyist creations.
I'm trying to think of uses, but maybe it would make a neat toy, all on its
own. You could wander around, and explore the world in terms of EM fields from
various sources. Now I want to make one.

\---

Edit: Thanks for changing the HN title.

Cue shocked reaction that our smartphones continue to process data, update
apps, background process things, and collect garbage when the screen is off.
This title is so link-baity that it makes me want to not click the link.

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xgbi
So what? Any phone will do that, the GSM connection is turned on pretty much
all the time. It would be more interesting to see what are the differences in
the illumination between this Android and a dumb phome from the 2000s.

What did he think? That his phone magically wakes up when somebody calls him?

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toothbrush
This reminds me of those stickers that one could put on your GSM a hundred
years ago which lit up when there was an incoming call. Similar principle at
work in this demonstration:
[https://youtu.be/CNJVhzOjWgU?t=12s](https://youtu.be/CNJVhzOjWgU?t=12s)

~~~
ChuckMcM
Wow the comments on that video, my eyes , my eyes!

I got a nice EMC probe for my oscilloscope (so that I could look at the
effectiveness of my bluetooth antenna trace) and it provides a nice way to
scan a phone for all of the various RF frequencies its putting out. One thing
I thought was interesting is that when you put your phone in a shielded box
(so that you're only seeing the phone's radiated signals) it bumps up the xmit
power in the GSM bands trying to talk to a cell tower it can't reach. Seems a
little mini StingRay on your dresser to reassure your phone that cell service
is nearby would help its battery life :-)

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pierrec
A comment on the presentation: disabling the controls on a slow-paced embedded
video is the epitome of minimalism gone too far. It feels oppressive (good
thing we can click on that Youtube icon to free ourselves from the oppression
of this minimalism).

With that out of the way, neat project!

------
JustSomeNobody
Sleep doesn't mean off. Sleep is a low power state and things are still
happening. Turn the phone OFF and try again.

~~~
mbell
I wouldn't be at all surprised that it would light up with the phone off too,
or really with any metal material set on it. You've got a free antenna set
above an already noisy circuit: the Arduino plugged into a laptop via USB.
Putting a metal cover over the antenna could easily be enough to increase the
field strength.

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sugarraps
Although indeed it may not be a surprise to us that our phones are always
awake, I love the design. It's simple and beautiful. What many of us try to
achieve with our web UI, epicjefferson has done with a simple object. Also, it
would be lovely to see this piece in an interactive museum for everyone to
place their phones.

Love it. Nice work!

~~~
epicjefferson
Thanks! I really enjoyed working on the enclosure the most, walnut is an
amazing wood.

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jkestner
Handsome. My unshielded speakers do something similar.

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btbuildem
Would be interesting to see what the readings are when the phone is "OFF"

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justifier
i was riding my bike today and wondered about a future where combustion
engines are outlawed and the streets were all electric

then i wondered how hot that world would be

our electronics pump out a lot of heat, and there are more electronics today
then yesterday and this trend will seemingly continue ad infinitum

i wondered if some of the planetary warming could be from all of the cycles

------
ljk
direct link to the video -
[https://www.youtube.com/watch?t=23&v=STIwphibwwg](https://www.youtube.com/watch?t=23&v=STIwphibwwg)

