Log data input from microphone jack

[Danjeffery07]

I am beginning a new project, a seismometer. I plan on building a small "slinky" sensor. It consists of a powerful rod magnet (neodymium) hanging from a coil spring (the "slinky"). There is then a wire coil surrounding the magnet, so when it moves up and down it produces small voltage spikes. I do know a decent amount about electronics but am more of a mechanical engineering guy. Everytime I play with transistors and whatnot I always end up failing, the best I did was plug one end of a cool lookin diode i ripped out if a circuit to a grounded cable and connect the other to a stereo jack and listened to a AM sports radio station.

I figured the easiest thing I could do is directly connect the output of the seismic sensor to the microphone jack of my computer (maybe, MAYBE if I can figure it out, put in an amp to make it more sensitive, so I can pickup small and distant quakes). One possible way I can record and visualize the data is through something like audacity which shows the audio in a graph, but audio files that long of time would be massive. Is there another program which would graph this data from the microphone jack and in other types of files which wouldn't be so big? Ive been scouring the internet and havn't come up with much. Thanks bunches

 

[CocaCola]

One possible way I can record and visualize the data is through something like audacity which shows the audio in a graph, but audio files that long of time would be massive. Is there another program which would graph this data from the microphone jack and in other types of files which wouldn't be so big? Ive been scouring the internet and havn't come up with much. Thanks bunches

Use a lower sampling rate and depth...

As for the rest, not sure exactly where you are heading...

 

[Mongrel Shark]

I've played with audio programs a lot. I also get the jist of what you want to do.

I think you need to look into data storage...... Or as Cocacola suggested. use a lower sample rate.

You could simplify things by using an Oscilloscope, preferably a DSO.( Digital Storage Oscilloscope, google that if I'm talking gobbledygook). you can get usb bits that do the job, or try something like the DSO 201 or 203 (Ebay, google) I have been playing with recently. I was playing with something similar on my desk a few months back that accidentally turned out to have potential as a seismograph. But I dropped it due to not wanting to re-invent a wheel...

Whatever path you go down I think you will end up needing a good storage device to save the data on. Your talking about taking many (hundreds? thousands?) samples per second and logging them. even if you break it down to binary your going to need a lot of space to record for a day or more.


I can only assume you would want graphs that span months, that can be scaled in to see seconds... Your going to need a BIG, moderately fast drive to do that.

Could I suggest a WD 1tb pocket drive? or perhaps a tape drive, although that's getting expensive....



Give us some more details and someone here might be able to help more. That's the best I can offer with what you asked...

 

[(*steve*)]

We have some members with seismographs at home.

Wait until they chime in, or search the forums for past threads.

It's a very interesting area.

 

[Mongrel Shark]

Yes. I have been thinking about this.

Using audio software to monitor could be a lot simpler than using a scope.

I'm keen to see what the experts have to say too.