Smartphone EMF Detector | Hacker News Reader

Smartphone EMF Detector

ledhack.org

77 pointsepicjefferson27 comments

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> 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.

no, we don't

> 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.

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.

yep, you got it.

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/

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."

It's fine to not know the difference between ionizing radiation and non-ionizing radiation but please don't give health advice based on that misunderstanding, you sound like an anti-vaccine activist.

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.

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...

thanks for the tip. Let's see where this project goes from here. I'm by no means an electronics engineer so any advice to get rid of incorrect readings or misinterpretation is more than welcome.

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.

Yeah, the circuit is very sensitive and noisy indeed, even my hand touching the phone would change the light pattern. I would love to revisit this project with some proper electronics knowledge. I'm open to collaborations ;)

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.

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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.

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?

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

Ha! So that's how those worked. Nice to know. :)

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 :-)

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!

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

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.

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!

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

Handsome. My unshielded speakers do something similar.

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

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

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

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