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Step 2A certain attraction
By placing a magnet inside the toilet paper roll and a reed switch inside the toilet paper holder we can count the number of revolutions of the toilet paper roll.
Less and less toilet paper is on the roll after each turn so the # of squares of toilet paper that each revolution represents will go down in increments. On our rolls of toilet paper there are 3.4 squares in a revolution in the beginning and 1.5 at the end. There are about 200 revolutions in the rolls. A simple bit of math and we have a good idea for how many are on each revolution.
r2 = new rotation count
r1 = previous rotation count
so, squares used in current session = (3.4 - r2 * .00475) * r2 - (3.4 - r1 * .00475) * r1
done
Less and less toilet paper is on the roll after each turn so the # of squares of toilet paper that each revolution represents will go down in increments. On our rolls of toilet paper there are 3.4 squares in a revolution in the beginning and 1.5 at the end. There are about 200 revolutions in the rolls. A simple bit of math and we have a good idea for how many are on each revolution.
r2 = new rotation count
r1 = previous rotation count
so, squares used in current session = (3.4 - r2 * .00475) * r2 - (3.4 - r1 * .00475) * r1
done
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