libraries you use will be supported.
If 5V is a must, you may have to
consider switching development
platforms. Both Atmel AVR and
Microchip PIC microcontrollers are
available that run at much higher
speeds and have better peripheral sets
while still using 5V. I'm afraid I don't
know as much about the AVR line,
but PIC18F, 24F, and 30F are all quite
powerful controllers. If you decide
to go this route, be warned that
the learning curve is very steep at the
start. Don't forget to compare performance by MIPS (million instructions
per second), not clock speed.
Another 5V solution is to use
a second Arduino. Using two board
lets you do twice the work at the
same speed. You can communicate
between them using serial or SPI/I2C
with the wire library. This can be a lot
of work, but it also may be the
simplest solution to some problems.
You may want to simply see if you can
improve your coding abilities.
Most people underestimate what
can be accomplished with a basic
Arduino or microcontroller. For
instance, if your code has delays of
more than 1 ms, there is probably a
faster way to run the same code.
Unfortunately, the Arduino libraries
are not really designed for the highest
performance. For example, the only
interrupts that are available using the
core libraries are for pin changes.
Many common programming techniques to improve performance rely
on timer, serial, and ADC interrupts. If
your code isn't proprietary, don't be
afraid to post it to the Arduino forums
to ask if there is a faster way to do the
same thing. If you already use the best
practices, they will also be able to
point you toward an upgrade that fits
most closely with what you need to
Jersey Shore, PA
#2 The Arduino is a great learning
platform, but it does have limitations.
If the issue is math crunching ability,
then you might look into a book on
algorithms to make certain you haven't
missed any computational tricks.
Another avenue is to use Assembler.
I've written directly to the I/O
hardware to achieve a nearly 100x
improvement in I/O handling. Lastly,
consider upgrading to a new card,
such as the chipKit series of Arduino
compatible cards. The problem with
this approach is cost (about the same
as a stock Arduino) and you'll have to
use the proprietary chipKit development environment. As a result, you
probably won't be able to port your
code back to a generic Arduino.
[#9133 - September 2013]
Need to See IR Light
I'm working with IR LEDs for a
wireless stereo system in my living
room. I'm having trouble visualizing the
dead spots (shadows). Do you know
any way to see the IR light distribution,
short of me buying a pair of those
night goggles from the military?
Most digital cameras are infrared
(IR) sensitive. The simple test is to
point an IR remote control at the
camera and watch the LCD screen.
For the "dead spots" or shadow tests,
turn all visible lights off, then turn on
your IR source. Look around the living
room with the digital camera (I
recommend lowering the screen
brightness), and see where there is no
illumination with the IR source.
[#7132 - July 2013]
I read your question and response
on Tech Jobs in the August 2013 issue.
Here is another response:
Your son should consider the
local community college, and look at
other careers related to electronics.
While engineers are often mentioned,
technicians with associate's degrees
are now more in demand (USA
Electronics is just one option —
also consider other related fields such
as machine tool technology, industrial
electronics, instrumentation repair, or
These programs include electronics
along with motor control,
programmable logic controllers,
instrumentation, fluid power, sensors,
pumps, valves, process control, and
These people are in demand and
command high incomes.
For info on career options and
certifications, check out the Electronics
Technicians Association International
Glen W. Spielbauer
[#7131 - July 2013]
One of the suggestions was one
that I was first tempted to suggest, but
did not as it is potentially dangerous.
The use of a filtering capacitor to
dampen the voltage should not be
tried. The sender circuit is low
impedance and needs a very large
value capacitor to be successful.
Unfortunately, that capacitor will store
quite a bit of energy and the sender
rheostat — in the presence of fuel and
air — could create a spark that is
sufficient to explosively ignite the fuel
vapor. (Think TWA-800.)
You have gotten a lot of good
suggestions. The best ones deal with
repairing the system as it was
designed. You might want to make
sure the sender is grounded properly
and try an external wire back to
the gauge to bypass the original one
as a test.
80 October 2013
Send all questions and answers by email to firstname.lastname@example.org
or via the online form at www.nutsvolts.com/tech-forum