Tell us about yourself!
Over what period of time were the voltage readings taken? Minutes? Days? Weeks?Did you measure current?
True. For ultimate breakdown speed, put it in a blender with water and make a slush out of it. Personally, I have a couple of 50-gallon planters I just toss the stuff in and periodically throw some wood chips on top. In a matter of months, it's all top grade potting soil. Guess I have better things to do with my time than spend it pushing food scraps into a tiny shredder.
I don't grind anything for my compost pile. Just toss it in and throw a little mulch on top. The worms are very happy.
Well, in that case, why not go out and buy a new MacBook, a USB to serial converter, an arduino and a motor. That way you could have the MacBook send instructions to the arduino, which could then control the motor.Oh wait!Why not hire someone full time at $100/hour to watch the MacBook, and use a timer to alert them when they should adjust the motor speed.Oh wait! Why not have a government department to set rules and conditions and regulations and...Part of learning is understanding when a "solution" makes sense, and when it doesn't. If you need programmable motor control, an arduino isn't a bad first approximation. But if you just need motor control - well, maybe you ought to put an ad on line for motor speed watcher guy positions.
I'm wondering how long you can run this before it falls apart.
google "motor speed control LM555".
Massive overkill to use an arduino for this. If you just want to control speed, a 555 timer circuit is WAY cheaper (about a 5-10 cents). If you want to control various intervals, a dedicated processor (ATTINY24/45/85 or ATTINY 13 - less than $1) will do the job.For switching applications (PWM), especially in battery-operated circuits, a MOSFET is generally preferred over a BJT because it wastes less power.
Since the peltier junction runs on temperature differential, instead of heat sink, try a can full of snow. When the snow melts, toss the water and refill with snow.