A year ago, I picked up a quad-slice Oster toaster, model number TSSTRT4SST (ToaSTeRToasts4SliceStainlessSteel ? Why 2 's''s in 'toaster'?).
It cost my $2 at the local Salvation Army, and I bought it only because it had wide slice apertures, and the false hope of a 'bagel' button.
I certainly got more than two dollars worth of misery out of it.
I'd like to think that it was just because it was second hand, and that my mate's often repeated snarl of 'Its worn-out' was true...but how does a toaster wear out? Mechanically it was fine, all the elements worked.
It was just a poor toaster, so when Liz got a new toaster for Christmas(Not the same model or company, I might add), I tossed the Oster onto the scavenge box, and took it apart this morning.
Like most modern crap,it contained a processor- the ABOV MC80F0604D. Or rather, it had two of them.
Now the specs for the MC80F0604D look half-decent: its clock speed is three times the PC I started with, so many years ago, and its nicely equipped with I/O. In fact, of the 20 pins on the uC, only 12 were in use.
It looks as though they created the four slice toaster by simply doubling the internals. One uC runs the right hand slots, and the other the left. This immediately brings to mind the North American F-82 Twin Mustang, a plane I always wanted to model, but, like the USS New Jersey, has always remained out of my grasp.
What is even nicer is that each uC is mounted on its own playing-card sized PCB, with a nice 5 pin header supplying power, and three pins of I/O. The PCB has three push-buttons, two LED's, and a potentiometer.
There are solder pads for two more switches.
It looks like a little dev board. Its so cute! If the MC80F0604D's Flash memory is acessable, I just took apart a two dollar toaster and scored two handy microcontrollers.*
I can't find any example circuit diagrams though, or any examples of homebrew programmers. Not so good.
As a final note, the toaster achieves the AC voltage step-down without a switching regulator or a transformer, by depending on the 10 ohm, 1400Watt resistance element to drop the voltage to ~12 volts.
This is (possibly) clever, although I didn't put an oscilloscope on Vdd to see how ugly the supply is - ABOV boasts some clever power conditioning/tolerance circuitry on the chip, and I suspect it was put to the test.
Metal case isn't grounded either. Actually, it couldn't be. If it was, a short from the elements to the case would be a wide-open arc flash, rather than a silent killer for the man who has one hand on the toaster, and the other on, say the kitchen stove.
I am a little annoyed that I din't find this sooner, for I would have modded the whole damn toaster, and sent it in for the Hackaday contest. Hold the 'Bagel' button down, and it blinks HACKADAY in baudot, perhaps. I'd try to install a TCP/IP styack and connect it to the Internet, but that idea is definately passe, if only because its so old.
I'm putting the boards away for now, but I will be pulling them out to act as the brains for something. If anyone has any schematics that show a MC80F0604D being programmed, I'd really appreciate a shout.
*If I can't then I still scored two pots and two thermistors, which is about $3 in parts, so I'm actually coming ahead.
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