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some home appliances use this technology. I have a refrigerator that can you hold your phone next too during a support call whereby the refrigerator emits some

some home appliances use this technology. I have a refrigerator that can you hold your phone next too during a support call whereby the refrigerator emits some tones that the support person can receive presumably into some computer program designed to decipher the tones as some error or diagnostic codes. I'm old enough to know all about those old school modems. I think this is stuff is cool for those niche type applications.

brian-armstrong 10y ago
That's a neat idea. You could imagine doing this in DTMF. The fridge could even place the call!
- ex3ndr 10y ago
  In most modern networks like GSM DTMF are send via non-sound channel. Actually that was done because of famous Woz's blue box.
kranner 10y ago
It is offered in some LG washing machines, to be paired with their iOS app. Unfortunately the last time I tried it, I could not make it work after 10 tries - 'too noisy' 'bring the phone closer to the speaker' etc. I don't live in a noisy neighbourhood either.
milankragujevic 10y ago
I have a small spy cam that I put on quadcopters. It has WiFi but it has no interface so to configure it you download a phone app and type in wifi credentials then it modules that into sound and plays the sound and the camera picks it up and configures itself and then you can watch the stream live over WiFi.
cuu508 10y ago
I did contracting work on an Android app which records diagnostic data from smoke alarms. You press a button on the alarm and it emits a high-pitched series of chirps. Phone records, decodes and displays stuff like battery level, time of last recorded alarm etc. The recording scheme was rather simple, only 10 or so bits per second, and used Manchester coding. Most problems I ran into were due to audio hardware differences on different Android phones. Some phones have multiple mics and there is no consistent way to specify which one to use (or, more precisely, to know the location of the mic used). One workaround for this was to record in stereo--phones would usually record the each mic to its own stereo channel. Then the app can look at both, and use the one with a better SNR. Some phones do proprietary audio filtering and noise reduction at hardware or driver level--you don't get access to the raw recorded audio data. On the upside, all phones these days are plenty fast to do CPU intensive audio processing.
madeofpalk 10y ago
I believe this is how the Amazon Dash buttons receive wifi network details from your phone.

brian-armstrong 10y ago

That's a neat idea. You could imagine doing this in DTMF. The fridge could even place the call!

ex3ndr 10y ago
In most modern networks like GSM DTMF are send via non-sound channel. Actually that was done because of famous Woz's blue box.

kranner 10y ago

It is offered in some LG washing machines, to be paired with their iOS app. Unfortunately the last time I tried it, I could not make it work after 10 tries - 'too noisy' 'bring the phone closer to the speaker' etc. I don't live in a noisy neighbourhood either.

milankragujevic 10y ago

I have a small spy cam that I put on quadcopters. It has WiFi but it has no interface so to configure it you download a phone app and type in wifi credentials then it modules that into sound and plays the sound and the camera picks it up and configures itself and then you can watch the stream live over WiFi.

cuu508 10y ago

I did contracting work on an Android app which records diagnostic data from smoke alarms. You press a button on the alarm and it emits a high-pitched series of chirps. Phone records, decodes and displays stuff like battery level, time of last recorded alarm etc. The recording scheme was rather simple, only 10 or so bits per second, and used Manchester coding. Most problems I ran into were due to audio hardware differences on different Android phones. Some phones have multiple mics and there is no consistent way to specify which one to use (or, more precisely, to know the location of the mic used). One workaround for this was to record in stereo--phones would usually record the each mic to its own stereo channel. Then the app can look at both, and use the one with a better SNR. Some phones do proprietary audio filtering and noise reduction at hardware or driver level--you don't get access to the raw recorded audio data. On the upside, all phones these days are plenty fast to do CPU intensive audio processing.

madeofpalk 10y ago

I believe this is how the Amazon Dash buttons receive wifi network details from your phone.