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finding and salvageing micro controllers

hello i was thinking about getting in to micro controller programing and i was wondering if it was possible to salvage (and use) micro controllers from old electronics. If so where should I look for them, and how do I identify to micro controllers I find.

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ZachS12 years ago

I've heard that using the control board from old hard drives may be possible. Some of these boards have more then one uC and a few inputs and outputs broken out on the bored. I don't remember where I read this but it was a security article about how the firmware on these boards didn't require a sig to install new versions in them. It would probably be a lot easier to just start with something like a arduino though.

westfw8 years ago
I have yet to see a mass-produced commercial product containing a reusable modern microcontroller (eg one with flash memory that can be erased.) I do sort of expect it to happen sometime soon, though.
Occasionally you can find a mid-range device (like an old external modem) that has an 8051 class microcontroller chips, and those can be jumpered to run from an external memory chip even if their original program was in internal rom. But it's a lot of work to get it to a usable state.
There seems to be a whole sub-genre of hacking involving devices that are actually tiny linux systems; most wireless routers, for example, and many multimedia players (mattel juicebox, for instance.

You do realize that today's microcontrollers cost well less than $5, have free samples readily available, and frequently have full development systems including a C compiler available for well under $50? See How to Choose a Microcontroller for some thoughts.
i realize that micro controllers are cheap its just i have a history of projects that don't work out so i was looking for ways to cut costs before i start a new hobby thanks for you help any way
NachoMahma8 years ago
. From what I've seen, most electronic items do not have a general-purpose, programmable microcontroller, eg, Arduino. They will have uCs that are dedicated to the job at hand and are not easy to reprogram. . But it's been a while since I salvaged electronics, so maybe some of the newer stuff has more flexible uCs. . . Most chips will have text printed on them that identifies what they are. Often dark silver ink on a black chip, so it can be hard to see. Type the text into Google.
if reprogrammable micro controllers are not used in most appliances and electronics why are they mass produced? and available from places like sparkfun for pocket change
. I don't understand the question. :(
it doesn't make sense that there are big companies that mass produce little chips if they survive mostly off hobbyists
AVR's actually are used mostly by hobbists, I believe. Or, at least, have a signifcant hobbist market. PIC's, on the otherhand, is probably what you'll deal with in real applications. However, companies generally use either one-time programmable chips to keep costs down, or set some internal setting that prevents them from being reprogrammed. Its not going to be worth it.
gmoon zachninme8 years ago
I'd say both Atmel and MIcrochip have a much more sizable commercial market than hobbyist...I wouldn't venture to say who "leads" with DIYers, but you may be right, Zach.

Parallax, on the other hand, is much more geared to the hobby crowd. You'll note that they geared their "next gen" 32-bit chips to fit into 40-pin DIP packages, while both Atmel and Microchip make 32-bit uCs in packages with huge pin counts (some have 256 pins, something most hobbyists could never tackle.) But the Parallax chips can't handle stuff like direct memory access, etc.

And right on--you can order AVRs and PICs preprogrammed at the factory, and most will have the "protection bits" set.

For high-volume products when an off-the-shelf uC won't cut it, there's ASIC technology, which can't be reprogrammed at all... (and other stuff besides ASIC, too.)
Goodhart8 years ago
At one time (and I even have a sample in my cabinet), EPROMs (Erasable Programmable Read-Only Memory), which included Old PC BIOS chips which were often EPROMs, and the erasing window was often covered with a label containing the BIOS publisher's name, the BIOS revision, and a copyright notice, and EEPROMs (Electrically Erasable Programmable Read-Only Memory).
Eprom32k.jpg