64 February 2016
READER - TO - READER TECHFORUM
All questions AND answers are submitted by Nuts &
Volts readers and are intended to promote the exchange
of ideas and provide assistance for solving technical
problems. All submissions are subject to editing and will
be published on a space available basis if deemed suitable
by the publisher. Answers are submitted by readers and
NO GUARANTEES WHATSOEVER are made by the
publisher. The implementation of any answer printed in
this column may require varying degrees of technical
experience and should only be attempted by qualified
individuals.
Always use common sense and good judgment!
>>> QUESTIONS
Thirst For Knowledge
I’ve been an NV subscriber for
years. I have an interest, but not a
proficiency — yet. Some articles I
understand, some I do not, and I
really would like to get to the point
where I can run with most things
presented in each issue, as well as
in other magazines. Coming up on
retirement, I will have more time to
invest in areas of interest. So, I’m
looking for guidance in a couple of
directions.
1. I want to get proficient building
things using small microprocessors
(home automation, data loggers
for temp and humidity, robotics,
small handheld computers, hacking
appliances, other??), but I’m not sure
where to start and the best way to
learn. I’ve built a few PCs over the
years, and while I would have to dust
off my memory, I have programmed a
little in the past with Visual Basic and
SQL.
2. I want to get more
knowledgeable in AC/DC electronics.
I’ve taken a basic fundamentals
course at community college a
number of years ago, but would
like to refresh that and get on
a path to continue building my
knowledge base in all aspects, be
it AC/DC electronics, computers,
communications, etc.
3. I have a two year old grandson
and I want to get him excited about
technology, programming, math,
engineering, etc., at age appropriate
levels, and see what — if anything
— he might want to do with the
knowledge as he gets older. Figuring
that almost any profession he chooses
will benefit from exposure and
proficiency in this area, and it can’t
be accomplished overnight.
Any insights, thoughts, sources,
books, coursework, etc., anyone
can share would very much be
appreciated, as well as any thoughts
on where you see all this going in the
next 20 years, so maybe I can guide
my grandson to get out in front of
things.
Thank you in advance for
anything you can share.
#2161 Mark McCurdy
Grapevine, TX
68HC11 To DS1302 RTC
I recently purchased what some
would consider a dinosaur when
it comes to microcontrollers: a
68HC11. I purchased it at an estate
sale because it was one I used while
attending school. My question is
where can I find info on creating
a program that would allow me to
interface the SPI to a DS1302 RTC?
#2162 Michael Bennett
Kankakee, IL
Cranky Flashlight
I have a three-LED hand-crank
flashlight. I’ve included a copy of
the PCB (orange) hoping to find out
where the problem may be. The
switch (SW1) provides two modes of
lighting: one LED only (LED2) and all
LEDs (LED1-LED3); in the OFF mode,
the hand-crank is to be used in order
to recharge the 3.6V rechargeable
battery.
The hand-crank flashlight works
in either of the two modes ONLY
WHEN the hand-crank is being used.
When I stop hand-cranking it, that’s
when lighting stops. I assume the li-on
battery is not being charged (no white
stuff around it for poor connection).
The black/plastic transistor is
marked as SC8050. NTE (NTEinc.
com) doesn’t have a replacement
for it. Can someone suggest a
replacement and if it’s NOT the
transistor, suggest where the problem
might be?
#2163 Nate Franklin
Schererville, IN
