value will be pretty close to 5V; when the device is in full
light, your voltage will be
5V ⋅ 10K 110K = 0.45V
Which is a pretty good swing from full on to full off.
A hobby servo wants a pulse of between 1 ms and
2 ms every 20 ms to operate. Some servos will go outside
of this range, but every servo will operate happily within
this range. There are a variety of ways to generate this
signal; using PIC assembly, a CCS C compiler in “C”, or PIC
BASIC or PIC BASIC Pro are three popular ones. There are
other compilers out there, as well. If there is interest, I will
create and publish source for those that want to create
such a handy little widget. I’ll bet that if you Google for it
on the Internet, you’ll find dozens of ways to do this
already. I don’t have any of these chips at the moment, but
I’ll get some and post code and a full circuit next month.
It will be September when you read this column and
there are competitions coming up. So, get your robots
ready to rumble and get out there to strut your (robot)
stuff! Keep those questions coming; there is nothing that
I like better than a challenge. Until next time, this is
Mr. Roboto signing out. SV
Industry guru Forrest M. Mims III has created
a stumper. Can you figure out what's missing?
Go to www.Jameco.com/question to see if you are
correct and while you are there, sign-up for our free
full color catalog. It's packed with components at prices
below what you are used to paying.
SERVO 09.2009 15