ATtiny Hacks: An Audio Alert For Cell Phones Accidentally Left On Vibrate

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[John Thomson] usually keeps his phone on vibrate when it’s in his pocket, and he often forgets to turn the ringer back on when setting it down to charge. This typically results in a bunch of missed calls in the meantime, so he had to devise a way to counteract his forgetfulness.

You might remember [John] from the Santa-pede contest we held last December. He wanted to try his hand at yet another competition, the Avnet Dog Days of Summer contest, so he scrambled to come up with a quick fix for his situation. He concocted a simple circuit based on [ChaN’s] design for a “Simple SD Audio Player with an 8-pin IC” that would alert him to incoming calls, even when his phone was on vibrate.

[John] used an ATtiny85, just as [ChaN] did, adding a speaker for sound output and a piezo sensor to detect his phone’s vibrations. When the piezo senses a bit of motion, the audio player kicks in, blaring a series of sounds that are sure to get [John’s] attention.

31 thoughts on “ATtiny Hacks: An Audio Alert For Cell Phones Accidentally Left On Vibrate

  1. (i’m pretty inexperienced, and can’t call myself a “maker”) great idea, but would it not be more intuitive to have just made something which would make a noise from the cell signal? Ie: sometimes when my phone is on silent but next to an electronic device it will cause interference. wouldnt this have been better than using a vibration sensor?

    1. Good idea, but my phone does the same thing even when it’s NOT receiving a call. I assume it’s updating the network or maybe checking for messages. To my ears, the interfering signal sounds identical to when a call or text is incoming, but maybe a bit of real analysis would reveal differences.

    2. Detecting the GSM RF was how I planned on doing it at first, but if you do a little experiment and put a phone next to a speaker that transduces the RF you’ll see that it buzzes even when it’s not receiving anything. I also believe the detection circuitry for CDMA RF would be different.

      However, now I’m thinking if I used both vibration and RF to trigger the alert it would result in fewer false alerts.

  2. I’m not bashing the project, but I’m a little confused… The cellphone is capable of not-vibrate. So if you have to remember to plug it in to this device, or set it on top of it, why not just turn off vibrate on the phone?

    1. It appears to function as a charging station from the writeup. I’m at work and cant browse youtube. I have the same problem though. I remember to take the phone in and set it down to charge but forget to turn the ringer off. This provides the notification and the reminder.

      1. I missed the charging part. That makes a lot more sense.

        My phone has me very well trained to check that it has WiFi turned on in the house (cellular coverage is poor) and to check the alert volume level when I plug it in to charge :)

  3. a huge number of phones have accelerometers in them, imo if the phone was still for 5 min (i.e. sitting on a desk) it should automatically switch to loud. In your pocket from general movement it would stay on silent.

  4. Hi, Jonathan Thomson here. You may remember me from such other hacks as “SMB pipe sound toilet”, “Hacking a cheap USBasp programmer”, and “The DIY Lightning Stick.” RIP Troy McClure.

    If you like the video, please give it a “thumbs up” on youtube. Number of “thumbs up” is 25% of the contest scoring.

  5. This is a very cool project. The thing is, merely setting my phone next to the box would remind me to turn the phone off of vibrate, every time. I guess that achieves the purpose too. (I’ve done this to myself many times — engineered a solution to solve a memory problem, then the solution reminds me to solve the problem the “right way”, rendering the solution unnecessary).

    1. When it becomes a problem again, do you reuse the old solution or have you forgotten it by that time and re-invent a suspiciously similar solution that reminds you that it looks exactly like your old solution?

    2. The idea is to replace your charger with the Vibe2Tone. The cable that charges the phone is short so it is hard not to put the phone on the device. With the Vibe2Tone you also don’t have to remember to turn the ringer off when the phone has finished charging because you never turned it on.

  6. My crappy $15 TracFone automatically changes from Vibrate to Loud Ring when I plug it into the charger. I figured more expensive phones (meaning EVERY OTHER phone) would have the same feature. Guess I won’t bother “upgrading” then.

  7. Rube Goldberg approves. How much more complexity can you add to a simple task of turning your phone off of vibrate? Perhaps a few Jacobs Ladders, and maybe some flashing spinner thingys could be added to the next version.

  8. I’m looking for something a bit similar to this. When doing outdoor gardening I often leave my android phone in a nearby building (I don’t want to risk water and dirt damaging the phone). Even with signal volume at max I sometimes miss calls. I’d like a simple, battery driven device that on vibration gives a loud noise, perhaps a doorbell. Is there already something with this functionality that I can buy?

    My android phone has a audio-out jack so I could connect it to a portable stereo or radio to amp up the ringtone. But that is very bulky. I’d like something smaller and more portable.

    Maybe a doorbell hack that sounds the doorbell when a signal is sensed from the audio-out from the phone? Any ideas on projects that already do what I’m after?

  9. Good use of technology but bad use of brain power to make a device do what it was origonally designed to do until you told it not to. Why turn the ringer off and on to vibrate if your going to hook up a ringer to it…. I am not the brightest crayon in the box but that seems a little back aswards to me.

  10. I’ll admit, my first thought was the ‘profiles’ options on some Nokia handsets that changed to a ringer setting automatically when plugged in. Not sure if any other phone does this out-of-box, but Tasker for Android should do the same thing!

    Aside from lazy alternatives, the idea behind this project is a lot more universal anyways. The peizo sensor is most likely the basis for a wide range of security products, and can be applied to various applications. Great idea and utilization of an Altoids tin! Love it.

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