servo limits and timing needs to be adjusted as each skull
and routine is different. This is very easy to do and can be
completed in a few minutes. Using a servo tester such as
the one designed by Tyler Straub makes this a breeze
The source code I use is available for download at the
article link. It’s provided under a Creative Commons
License, and you’re free to use it as long as it’s for
noncommercial use and you are willing to give credit and
license your new creations under the same terms.
DIGGING UP THE PARTS
I’ve tried to minimize the number of places I need to
shop from in order to gather the necessary supplies
needed to build my controllers. Many of my power
supplies are recycled wall warts. These are the cords with
the box-like plug that comes with most consumer
electronics today. I always salvage them when disposing of
any electronics and am always on the lookout for more.
Friends and family now save them for me, as well.
Be sure you use the correct voltage which should
always be checked with a voltage meter. Don’t trust what
the label says as the voltage can often be significantly
higher than stated. Using a supply with too high of voltage
can damage your components and let out the “magic blue
The SD cards used in audio players are the same ones
used in many cameras. You may have extras lying around
the house, or they’re easy enough to get at most
department or drug stores. The PIR sensors I use are
available from Parallax (see Resources). Some of these
components are available on eBay,
but oftentimes the long wait times
and not having the opportunity to
talk with someone regarding any
issues keeps me from using that
option. All the electronic parts
except for the PICAXE chip and the
audio board come from the same
Even so, the shipping costs can
add up, so I try to plan my parts
needs for the season and order
enough plus a few extras at one
Knowing how to solder is a
necessary skill. While having
someone teach you at your side will
speed up the learning process, I
learned by watching online videos.
One of my favorite tutorials for
soldering is done by Dave from the
EEVblog (see Resources) His three-part series covers tools and
materials, as well as basic and surface-mount soldering.
This process has been highly rewarding and satisfying.
The lessons I’ve learned have allowed me to build
controllers to do exactly what I need and to keep the cost
in a range that I can afford. It’s a never-ending process as I
continue to improve my current boards and develop new
ones. In fact, I’ve teamed up with another haunter to
create an even more user-friendly Frankenstein board
which will allow just about anyone with soldering skills to
get a three-axis skull up and running in a day.
If you have any questions or would like to discuss the
many uses of the PICAXE microcontroller or any other
projects, please come and visit the Nuts & Volts forum.
We’re all here to help out and have fun! NV
September 2014 73
FIGURE 10. Tyler's DIY servo tester.