[HN Gopher] AppleWatchAmmeter
___________________________________________________________________
AppleWatchAmmeter
Author : rcarmo
Score : 221 points
Date : 2024-09-11 07:01 UTC (15 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| kstrauser wrote:
| That's genius in its simplicity. Wow. Well done!
| 8338550bff96 wrote:
| Simple genius is the only kind I recognize
| bri3d wrote:
| See also:
| https://phyphox.org/wiki/index.php/Smartphones_as_ammeters - I've
| heard of some physics instructors using this in teaching
| settings.
|
| I'm quite surprised that nobody has made an app which can do some
| baseline calibration and produce real-time current measurements
| yet; it would just be a few hundred lines of code at most.
| _Microft wrote:
| Phyphox is amazing: there is a wide variety of different
| experiments available using all sorts of sensors found in
| phones. The iPhone accelerometer seems to saturate at roughly
| 13g, easily achievable by pulling your phone very fast in an
| increasingly narrow arc towards yourself. What were you
| thinking how I found out?
|
| (Fun fact: this is another project that Sebastian Staacks of
| http://there.oughta.be worked(s?) on. You might remember his
| wooden Gameboy shell, the Gameboy interceptor to screenshare
| the Gameboy screen to a PC or his bullettime video booth.)
| radicality wrote:
| Thanks for that recommendation, really good app. In today's app
| landscape it's almost unbelievable that it's so polished and
| free and without ads / signup links / always-on location
| sharing etc.
|
| It's not even easy to find. Few months ago I wanted a simple
| audio spectrogram app, downloaded some which wanted dubious in-
| app purchases, or had ads. I hadn't come across it earlier, but
| Phyfox does what I wanted better and for free.
| _Microft wrote:
| > _A circular coil of wire with N turns and a diameter D will
| generate a magnetic field of B = u0.I /D (u0 is defined to be
| 4.p.10^-7);_
|
| That _u0_ is meant to symbolize _m_0_ (mu zero, with zero being
| subscript) the vacuum magnetic permeability [0], in case you were
| wondering where that magic constant came from.
|
| [0] https://en.wikipedia.org/wiki/Vacuum_permeability
| lapetitejort wrote:
| See also e_0 [0]. 1/sqrt(e_0*m_0) = c, the speed of light
|
| [0]: https://en.wikipedia.org/wiki/Vacuum_permittivity
| cdchn wrote:
| It would be cool to use this as a voltage sensor, to check for
| live circuits, but the downside being you might not want to crane
| your wrist towards said live circuits.
| atoav wrote:
| And: measuring current can be done with any odd hall effect
| sensor, voltage not so much.
|
| I imagine a smart warch with two 4mm banana-jacks isn't going
| to be the next big thing.
| cdchn wrote:
| The pen size of my non-contact voltage detectors make it feel
| like it couldn't be THAT hard.
| ComputerGuru wrote:
| As TFA mentions, detecting AC current is rather different from
| detecting DC current (the article is about the latter).
| boomskats wrote:
| Only somewhat related, but wasn't there a DIY biohacking[0] craze
| a few years ago, with people implanting rare earth magnets into
| the tips of their pinky fingers, waiting for the nerve endings to
| heal around the implant, and then supposedly gaining a 'sixth
| sense' of being able to detect the flow of current via their
| bionic pinky? Is that still a thing?
|
| [0]: https://www.wired.com/story/diy-biohacking/
| Gracana wrote:
| I recall Zoe Quinn wrote about having that done ~10 years ago.
| Article's still up on her site, it's a good read:
| http://www.beesgo.biz/magnet.html
| gxs wrote:
| What am obnoxious mobile site you've linked to - unusable
| because of a persistent floating graphic over the middle of
| the screen.
| zitterbewegung wrote:
| Yes, there was but the magnets can break and I believe getting
| them removed is hard.
| Spivak wrote:
| Given how well-trodden putting hardware in humans is, I'm
| surprised this wouldn't be a <60 minute surgery to affix the
| magnet to your bone. Then it wouldn't look so weird pulling on
| your skin. Then again, the non-invasive version is wearing a
| magnetic ring, $1.34 on Aliexpress.
| ramses0 wrote:
| Similarly: supposedly superglue a magnet to your fingernail.
| kstrauser wrote:
| Having worked in orthopedics quite a bit, and hanging out
| with my wife who's a foot and ankle surgeon, there aren't
| many ways you could attach something to a bone that wouldn't
| cause problems. Other than the (significantly large, true!)
| hard mineral portion, bones comprise a lot of types of living
| tissue and you don't want to make a hole in them or their
| periosteum wrapper unless you absolutely must. The least bad
| approach might be something like a zip tie that you could
| carefully work around the bone, but even that would have
| ridges to irritate tissues and semi-enclosed spaces for
| bacteria to turn into a strip mall.
|
| I highly recommend just getting that magnetic ring instead.
| fudged71 wrote:
| Based on a quick search, a small gap (less than 500 mm)
| between the implant and bone can actually support
| osseointegration by allowing trabeculae to form. 3D printed
| titanium has been used a lot for osseointegration.
| kstrauser wrote:
| Quite possibly, but 1) you better be A-OK with having
| whatever it is permanently grow into your bone such that
| you'd have to carve it out with chisels or saws, and 2)
| you still need to hold it there long enough for that to
| happen, ideally without whatever mechanism you're using
| for that also being incorporated (like, literally
| incorporated).
| sonofhans wrote:
| > incorporated
|
| This took me longer than it should have. Nicely put.
| ASalazarMX wrote:
| > I highly recommend just getting that magnetic ring
| instead.
|
| But wearing a ring, while convenient and safer, is not biO
| hAcKiNg. It gives no bragging rights.
| kstrauser wrote:
| Neither does MRSA.
| crumpled wrote:
| I think the pulling on the skin part is essential to the
| feeling things part. I don't think people will get any
| sensation if the magnet is held stationary.
|
| I'm only guessing.
| cmsjustin wrote:
| https://www.youtube.com/shorts/17l9BucbXec
| fragmede wrote:
| http://dangerousthings.com graduated to selling implantable
| rfid u2f tokens.
| Onavo wrote:
| You can experience the same thing by supergluing a magnet to
| your pinky.
| surfingdino wrote:
| Must me useful for emergency proctologists. Neodymium magnets
| would probably work better for such applications.
| shagie wrote:
| > ... with people implanting rare earth magnets into the tips
| of their pinky fingers ...
|
| Imagine the joy of getting an MRI and forgetting about that bit
| of biohacking.
| markx2 wrote:
| I had an MRI.
|
| I have tragus piercings where the rings are titanium but the
| balls were steel. It was missed that they were there.
|
| I have surgical steel self-done implants in each hand.
|
| I have a magnet in one of my fingertips
|
| I have NFC chips in both hands.
|
| I did not explode, nothing felt hot, the only sensation was
| my tragus piercings wobbling slightly.
|
| This whole MRI thing ....
| parhamn wrote:
| "Don't take in ferromagnetic metals that would get pulled
| by a 3T magnet with 6 inches of separation" is a bit harder
| to grok for pretty much everyone.
| actionfromafar wrote:
| Are you real-life Wolverine?
| edm0nd wrote:
| I have an implant and MRIs or Xrays cause zero issues.
| shagie wrote:
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4848040/
|
| > The static magnetic field B_0 of an MRI machine attracts
| ferromagnetic objects and accelerates them toward the
| center of the bore of the MRI scanner. Ferromagnetic
| objects such as coins, hairpins, steel oxygen tanks or
| scissors can be accelerated or torqued by B_0 [4,10] and
| become dangerous projectiles [51]. The MRI safety program
| of the facility needs to warn about the misconception that
| larger objects will resist attraction to the field and need
| to emphasize the relationship between object size, material
| components, and projectile risk. Insufficient MRI safety
| training of ancillary medical personnel has led to fatal
| accidents when medical and other equipment was accelerated
| into the bore of the magnet [50,51].
|
| X-rays would be no problem. Having something that is
| attracted by a magnet (such as another magnet) may cause an
| issue.
|
| https://pubmed.ncbi.nlm.nih.gov/38128958/ has more on the
| "stuff flying into an MRI with concerning force."
|
| Things like a 10p coin imbedding itself 0.5cm into
| ballistic gel. A spoon going in 3.5 cm is a bit more
| concerning.
| edm0nd wrote:
| I don't have the biomagnet implants, I have the NExT RFID
| + NFC chip by DangerousThings in my right hand so its not
| as much of a concern.
|
| Just go read straight from the source instead of linking
| research papers.
|
| It has the warning of:
|
| >MRI COMPATIBILITY WARNING The xG3 and all magnetic
| implant products should be removed before any MRI or
| magnetic imaging procedure. While our x-series
| transponders have tested as compatible with MRI machines
| up to 7T field strength, all magnetic products are
| incompatible with MRI machines and procedures.
|
| https://dangerousthings.com/product/titan/
| shagie wrote:
| The comment that I originally responded to was:
|
| > with people implanting rare earth magnets into the tips
| of their pinky fingers
|
| And I was specifically referring to those rare earth
| magnets.
|
| Your comment then:
|
| > I have an implant and MRIs or Xrays cause zero issues.
|
| You gave no indication about what type of implant you
| hand or its manufacturer, and replying to my comment I
| took it in context that it was a rare earth magnet.
|
| Failing any information about the manufacturer, the
| information that I am able to provide to say "this can be
| dangerous" is research papers.
|
| You have further clarified that you only have a RFID and
| NFC chip implanted and not any magnets ... and provided a
| link to another product (rare earth magnet implant) from
| the same manufacturer that indicates that it is indeed
| dangerous when near an MRI machine which agrees with the
| original comment.
| dylan604 wrote:
| I would love to see how TSA reacts to your scans
| brcmthrowaway wrote:
| I wish Nokia was still around, this would be turned into a
| feature. Think N95 was a smorgasboard of random features.
| dang wrote:
| We changed the URL from https://hackaday.com/2024/09/10/the-
| apple-watch-as-an-ammete..., which points to this.
|
| Submitters: " _Please submit the original source. If a post
| reports on something found on another site, submit the latter._ "
| - https://news.ycombinator.com/newsguidelines.html
___________________________________________________________________
(page generated 2024-09-11 23:00 UTC)