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DIY Microprocessor Sound Level Meter Demoed At MIT
An anonymous reader writes "A Piezoelectric Sound Level Meter was demoed at MIT's Battle of the Bands last month, borrowing its display from the do-it-yourself USB LED marquee that was the subject of a previous Slashdot story. This video tutorial describes in detail both the analog electronics plus the C code that runs the system. If this is your first experience at the intersection of digital and analog systems, don't be scared!"
ok so pretty cool, but can someone explain how hooking a mic up to an ADC is worthy of a mention for MIT? It sounds more like a high school project at face value, what am I missing?
It IS a high school project at face value. The kit can be yours for only $80!
Shouldn't ads like this be paid for?
Sound level meter? Did i miss something particularly difficult or innovative about this thing?
Whats the point? Selling MC Kits?
Using off the shelf components that do the job with a setup that's practically plug'n'play doesn't always help you learn how something works.
"Re-inventing the wheel" can be a good way to learn & understand how something works and why it's built/programmed etc. in a certain way.
To do something right, you often have to roll up your sleeves and get busy.
Take a look at the video. The point of the exercise is to show/learn how to measure tiny voltages with a microcontroller. There are ready-made chips for some applications, like a VU meter, but a microcontroller is programmable and therefore much more flexible. It can process, store, and transmit the data it gets from its sensors. (Your single chip VU meter doesn't have a peak indicator? You want your data to be averaged over a second? You want to keep a record of the evening's sound levels on an SD-card? A microcontroller can be reprogrammed to include these features. A dedicated chip needs to be replaced - that is, if you can find one which has the features you want.)
It certainly can. But it can also be a way of teaching students the wrong way to solve a problem. In the "real world" that involves money, you must never ever re-invent anything until you have made completely sure that there is no better alternative. It is far too common that graduates don't realize this when they enter into professional life.
Besides, maybe the alternative would be to invent something completely new and more advanced using the "plug'n'play" components. That could teach you equally much, if not even more, about how the technology works. And what's more, it could actually be applicable knowledge that is useful for something.
While there's some truth to what you say, if we all just decided to use off-the-shelf components to do all of this stuff, people would forget how it's done, and then it would be arcanum.
The MIT approach of using a bulldozer to crack a nut usually demonstrates a pretty fine control over the bulldozer, and a reasonable understanding of how much force to apply to the nut and not end up with powder. It usually somehow comes across with a bit of controlled elegance amid the mayhem. :-P
Isn't the whole point to be doing the science and technology for the sake of doing the basic science and technology? I applaud anyone who can and does go back to first principles -- because, quite frankly, I can't do it myself. It's just good to know someone is keeping it alive.
Cheers
Lost at C:>. Found at C.
As an EE undergrad who is about to graduate, I wonder what planet you're from suggesting that any self-respecting nerd would use assembly for microcontroller programming.
As an engineer, you need to understand tradeoffs. Assembly allows you a greater measure of control and sometimes speed (it's really difficult to outdo a compiler in optimizations these days). In return, you have longer development times and you're more prone to bugs. In the projects I've worked on, coding in C is sufficient 95% of the time. In the other 5%, I can break out the assembler. By choosing the right tool for the right job at the right time, I can create better things.