Issue
140 March 2002
Spy-Size
Event Logger
byJeff
Bachiochi
When
it comes to performing a time study or logging events,
the more information you can gather, the better. Jeff
set out to build a small event logger to track events
during the off/on cycles of his water pump.
Start
•
Periodically • Event-Driven
• Tiny Dancer• I2C
For Your UART • And Now,
Back To The Show •
RTC Group • User Group
•
Event
Group •
Mission
Possible •
Make
An Appointment •
Sources
& PDF
My
wife Beverly and I often drive differing routes to get
to the same location. This causes arguments on just which
route is the quickest or shortest. When I’m driving alone,
I might try both routes and compare the number of stop
signs, traffic lights, speed limits, total distance, and
a number of other secret ingredients to come up with a
clear winner. I don’t know if she’s guilty of this, I
doubt it matters much to her, but I find it a constructive
exercise in time study.
Time
studies are a great tool for determining the health of
things. The term time study might bring to mind a way
to determine how close a job came to the actual estimate.
As previously illustrated, this doesn’t have to deal with
the work environment. It may not be obvious, but much
of this is built into today’s technologies. Your car may
provide you with a running miles-per-gallon indication,
which can indicate engine performance and help to determine
when a tune-up is necessary.
Data
logging is an integral part of a time study. A data logger
samples and stores data values in one of two modes, either
periodically or on event. A periodic logger would sample
and store data at predefined and equal intervals. An event
logger would sample data only on a specific occurrence
of a trigger. There are differences in what must be logged
for each of these modes.
