Mouse Powered Amulet
The AmuletThe Amulet2e is a asynchronous implementation of the ARM processor capable of 40 Dhrystone MIPS with a Core power efficiency of 290MIPS/watt. As it is asynchronous it will change speed dependant on the voltage supplied. Normal operation is at 3.3v but the processor will work correctly down to 1v.
The MouseAs a real live mouse is not a very reliable piece of equipment we chose to buy a toy mouse (No longer available in the shops!). The mouse runs quite slowly and not in a straight line.
The SetupThe mouse wheel was connected to a LEGO motor and generated about 4v but unfortunately with any load across it it drops down to less than 2v. The mouse having wobbly wheels (the box calls it "With Realistic Action") constantly wants to escape the wheel and often hits the spokes of the wheel and slows it self down. At this point the electricity generated drops down and the amulet slows down. The oscilloscope in the background is measuring one of the I/O lines flipped up and down in a software loop. As the mouse gets stuck the voltage drops the the processor slows down. There are some capacitors to stop the input voltage dropping down to 0v.
There are two video formats available. RealPlayer or MPEG.
The FutureWe hope to capture one of the real rats living in the bushes outside the department and use it to power a few chips. As a mouse can generate about 1Watt so a rat should be about 2Watts thus a rat can generate 580 MIPS on Amulet2s. This is very good when compared with a processor like the Athlon which uses 60 watts(30 Rats) to produce the same speed.
I am currently working on a fully Delay Insensitive MIPS compatible processor which will take even more punishment (I was thinking of sticking it in an oven at 200c and see it slow down). And it will be 30% faster than the original synchronous design.