Real-Life Math -- Solution
You are trying to get a computer to demodulate, or decode, an encoded
wireless signal.
1) You need to convert all of your units to Hz. If
there are 1 million Hz in a MHz and 1,000 Hz in a kHz, what are your final
values?
29.4912 MHz x 1,000,000 = 29,491,200 Hz
46.875
kHz x 1,000 = 46,875 Hz
2) You are using a timer interrupt, a device
that lets you pause the normal sequence of events taking place at precisely
timed intervals. To work properly, the timer needs to be set to the number
of CPU cycles between each signal sample. How many cycles does the CPU have
between each time the signal is sampled?
Number of CPU cycles between
each sample = The frequency of the CPU / The frequency of the sampler
Number
of CPU cycles between each sample = 29,491,200 / 46,875
Number
of CPU cycles between each sample = 629.1456
The CPU has 629 cycles
between each signal sample.
"Math is very important up
to the level of algebra and trigonometry, which I use frequently," says Mike
Fraser. He is a hardware engineer.
"Calculus, however, is not so important,
with the exception that you need to excel at calculus to obtain your university
degree."