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Phyphox – Physical Experiments Using a Smartphone

248 pointsby _Microftyesterday at 8:38 AM35 commentsview on HN

Comments

davidhoellyesterday at 12:48 PM

The coolest thing I ever did with that was finding wires in a friends wall - we needed to drill a hole and it was unclear whether the wires went up (problem) or right from the outlet. I didn't have a cable finder on hand but did have the epiphany to put a large load on the outlet (we used a kettle, a hairdryer would also work, just needs a lot of watts) and use the Fourier transform magnet spectrum to find the 50 Hz grid frequency in the wall. Worked beautifully.

Sadly, since most smartphone magnetometers seem to have a sample rate of 100/s, this will not be applicable to Americans and everyone else with a 60 Hz grid frequency, the 50 Hz were already at the Nyquist–Shannon limit.

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slow_typistyesterday at 11:19 AM

There is a paper you can cite if you use phyphox professionally.[1]

In Germany phyphox is quite popular in physics education.

However on android the sampling rate of the acceleration sensor is limited to 50/s. At least if you install through the official app store.

[1] https://iopscience.iop.org/article/10.1088/1361-6552/aac05e

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samchyesterday at 11:37 AM

One of my kids has science project due each quarter in school, and this is our go-to app. We’ve measured acceleration in an elevator, sound attenuation of an audio source in a small vacuum chamber, and the Doppler effect. The app makes it easy to capture and export the data points to make graphs. I highly recommend this even just to play around with.

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sudbyesterday at 5:24 PM

I think there's loads of scope to use phone cameras as dataloggers too, especially for older equipment that doesn't have an easy way to connect/export the data.

(I've been meaning for ages to write a piece of software that's able to extract change over time data from a video of a 7 segment display, like on a balance or a digital thermometer or something)

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trebligdivadyesterday at 10:08 PM

Damn that's very impressive - for a long time Android had a lot of hopeless accelrometer, audio scope, etc apps, and it's always been hard to add your own stuff to it. Sounds very very neat!

gozjsbtmyesterday at 8:16 PM

Coincidentally, I downloaded the app yesterday. In 10 min, in my mitchen, I found g ~ 9.7 m/^2 using a cheap kitchen spring scale and the accelerometer (without g) sensor. Quality app.

xnxyesterday at 2:02 PM

Seems like a more advanced version of Arduino Science Journal https://www.arduino.cc/education/science-journal/

OuterValeyesterday at 1:20 PM

I've had great fun using Phyphox to visualise my hand getting closer/farther from my phone based on the presence of my magnet implant. So many cool little things the app can visualise and measure, especially when used it creative ways.

perlgeekyesterday at 12:26 PM

I used it just the other day.

My parents have a sound bowl, and I wanted to know the resonance frequency. Took an audio spectrum, zoomed in on the first peak, read the frequency (iirc it was around 208 Hz).

tomaskafkayesterday at 11:27 AM

It’s the GOAT - I showed the app to a bunch of secondary school physics teachers and they were thrilled.

_Microftyesterday at 8:39 AM

The title was slightly editorialized for clarity.

DaSHackayesterday at 11:52 AM

I've been using Trail Sense [0] for sensor-related information after learning about it from a friend.

The interface is more polished, but the information is less technical than Phyphox (as the app is geared towards being a survival toolkit).

[0] https://github.com/kylecorry31/Trail-Sense

q3kyesterday at 10:59 AM

Good toolkit to have around. Recently used it to verify the true RPM of a system (using the accelerometer spectrum tool) against its control loop implementation.

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black6yesterday at 6:15 PM

If you prefer not to deal with an app store: https://www.apkmirror.com/apk/rwth-aachen-university/phyphox...

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Kevin_VAIyesterday at 2:52 PM

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takahitoyonedayesterday at 1:14 PM

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henryAlbigaleyesterday at 10:03 AM

Cool app dude