Earthquake alert system

 

[Roteno's] submission for the 555 timer design contest is an Internet connected earthquake alert system. It monitors the USGS website for earthquake data and plays a tune when an earthquake occurs. The data is available as a feed in the form of a TXT file which is pretty easy to parse using cURL. He chose an LPCXpresso board (which is an ARM development platform that can run a Linux kernel) along with an XPORT module to handle the Ethernet traffic.

So where does the 555 timer see some action? It is responsible for playing the tone when an earthquake is detected. But playing just one pitch isn’t much fun. Instead, [Roteno] built the circuit above which creates a resistor network switched by a series of transistors. This way he can use GPIO from the microcontroller to choose different pitches. Check out the video after the break to hear the results. At power-up all eight pitches are played as a test, and the alert sound varies in pitch and tempo based on the magnitude of the earthquake.

Comments

  1. Stendall says:

    I don’t think this project is much built around 555.
    You can take out the 555, replace with a endless list of integrated circuit and it will be more/less the same.

  2. Rodders says:

    If he used it to monitor the earthquakes here in Christchurch New Zealand it would be playing tunes non stop all day.

  3. mikuslaw says:

    You can always replace 555 with endless list of integrated circuits.
    But of course the project is not built “around” 555, it is only a small part. 555 contest is not limited to using 555 as main part of design.
    I like the switching resistor network part. I just wander how accurate is it and how much does it matter what type of transistor is used (bjt/mosfet).

  4. Stendall says:

    Rules

    All electronics are fair game (including all flavors of the 555/556/558). However, those deemed to not be using the 555 as a major component of their design will be penalized in judging. (i.e. using a microcontroller and only using the 555 for a small part of the application will not be as highly judged as someone using a 555 as the main controller in the design)

  5. Kris Lee says:

    @Rules

    The 555 part would have more kick when presented as 555 synthesizer what it essentially is.

    At current configuration the remaining part does confuse people unfortunatelly.

  6. Stendall says:

    MCU + 555 used as synth looks like a rules draw. :)

  7. HIrudinea says:

    Just an obversation, if an earthquake happened to you you wouldn’t need the system, and if it happened far away from you who cares?

  8. HIrudinea says:

    P.S.

    An obversation is what dyslexics call an observation.

  9. Jan says:

    Man this is lame

    Why he didn’t use the CV input of the 555 to control the frequency? I hate circuits that waste parts for no added effect. Asides from the ARM-based µC being able to produce variable frequencies the pitch control circuit is crap.

  10. ttom says:

    @Jan

    If you are trying to avoid using a D/A then using pin 5 doesn’t do much for you. If you used the D/A then making use of the 555 doesn’t make much sense. I see no waste here. Just a fun project. Pitch control is based on the resistors so pick resistors to your liking.

    Post us a link of your work that must be great.

  11. buzzcracked says:

    So the ARM MCU can probably do the tone generation. I hadn’t thought of using a 555 as a peripheral device like this though. This may spur more thoughts on how one might use the 555 with a MCU. Hardware solutions help deal with real-time constraints.

  12. holly_smoke says:

    No buzzcracked, interrupts help you deal with real time constraints.

    This project is a complete waste of time.

    You could use any old GPIO pin together with a timer interrupt to generate any pitch you want with just a few lines of code.

  13. ttom says:

    @holly_smoke

    There is no doubt that the ARM is capable of generating a tone either with an A/D, timer, or GPIO.

    “interrupts help you deal with real time constraints” is a very simplistic view of dealing with real time constraints. Mentioning interrupts doesn’t add anything to the discussion as there are many ways to deal with real time constraints.

    I agree with Buzzcracked. In concept hanging an IC peripheral (especially a cheap one like the 555) can help with real time & open up resources for other uses.

    As for waste of time, I rather read about a project built then talked about. No projects are a waste of time. Only comments. :)

  14. Nick Scott says:

    I live in Christchurch (just to the east of the CBD cordon), and I can tell you that right now, we have a much better earthquake alert system. It is called the earth. Great at letting us know when theres one we shoud be paying attention to.

  15. Jared says:

    I live in Christchurch, and I’m working for people who are making a PROPER earthquake warning system. It can give you warnings BEFORE the earthquake even arrives!

    We’re currently testing it with search and rescue, and the few seconds warning means they can get into a safe position.

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