DUSTYGRAVES Dusty Graves dustygraves.com dustygraves.com DUSTYGRAVES.COM robin dusty graves ROBIN DUSTY GRAVES robindustygraves ROBINDUSTYGRAVES robindustygraves.com robindustygraves.com ROBINDUSTYGRAVES.COM robin@dustygraves.com ROBIN@DUSTYGRAVES.COM kidbots.com  kidbots.com KIDBOTS.COM ROBINDUSTYGRAVES@KIDBOTS.COM robindustygraves@kidbots.com GRAVITATIONALRESEARCH GRAVITATIONAL RESEARCH gravitationalresearch gravitational research GRAVITATIONALRESEARCH.COM gravitationalresearch.com  gravitationalresearch.com

               HOW TO page 3


In my first prototype, I used a joystick, 15 pin connector, which
I cut away from an old, non-working joystick.

of the connector is supplied with +5 Volts FROM the
computer, however, early PC's and 80-86's, and 80-186's
typically had no sound cards which is where you find the
15 pin joystick port. If your computer has a sound card
with added sound and joystick ports, you can
find an old joystick, test wire - to -pin for pin 1, and you
will have a handy source to connect and unplug from when
needed. If you cut a cable, after finding pin one, plug it in
the port and CHECK again that the wire has +5 volts,
before you wire it in to your circuit!

Also, note that the KEYBOARD has one pin with +5 volts on
it, so that it is possible to wire into the DIN plug, although it
would require 2 plugs ( male and female ) and a connector to
add to the wire in between. I have used these double keyboard
connectors for specialized peripherals, such as complex joysticks
and a CAT ( as opposed to a MOUSE ), but the connectors are
typically difficult to find, and expensive. As always, if you
do get a plug or wire, be certain to connect it to a computer and
use an electrical meter to check that the wire you think is +5 volts
actually has +5 volts on it before wiring in to your circuit.

     If you were adventurous you could just add a
connector on the keyboard itself, but this
would require you to dissassemble the keyboard and add a
connector of some sort. Most people would not know how to
do this, and it is beyond the scope of this "how to " instruction.
You would have to use a meter to find the +5 volt wire,
and connect a plug to it, and the ground wire.

As well, you can disconnect ANY of the cords, such as the
keyboard, the joystick, etc. that have +5 Volts in them
and just cut the wire at any convenient spot, test +5 volt PIN
to bared wire end, add a plug connector on the wire, and
finally solder the cable wires back together. This way you
do not have to buy special adapters - use the ones you
already have, - note that the keyboard or joystick will still
work as it always did. A method I use, in order to do the least
amount of damage to the cord, is to carefully slit the cord
with a typical dollar store click cutter, and expose the wires.
Use an electrical meter with one end to a known ground, like
the computer case, and carefully put a sharp sewing needle
through the wires, one at a time, until you find +5 Volts.
The tiny hole in the plastic insulation on the wire seals itself.
Also test to see a wire that shows ZERO VOLTS to ground,
and this would be the ground wire. Then
slit the known +5 Volt wire, and solder on another wire going
to your circuit board. Wrap with electrical tape. Done. ( I often
cut the wire itself, slip on some heat shrink tubing, solder the 3
ends, and then shrink the tube in place for a more professional

     Older PC computers did not have a USB port, but, if you are
using a newer PC, say, a 486 to make a controller, you can use
an ordinary USB plug and cable, since there are +5 and Ground
wires on USB which is extremely handy. I will NOT include a lot of
information on using USB power since it is risky and complicated
- especially for the intended audience of typical 10 year old kids
that this website hopes to ecourage to start computer - robot -
programming, free, or inexpensively. Be certain to read up on this
subject or get help if you decide to try using USB. Even large
manufacturers violate standard USB specifications, which are
surprisingly complicated... A good example is the external harddrive
SEAGATE ONE TOUCH 4 MINI It shipped with a USB cable
with 2 USB ends on the computer side- you are instructed to plug
in the main one first, then the second. I took an electrical meter
and tested the ends and they were identical to a cheap dollar store
double ended "CHEATER" USB cable that gets twice as much
power by plugging into 2 ports. Any USB information on the web
about these cables states that they are dangerous, that they violate
all USB codes and standards, and to avoid them! I tried the cheap
Dollar Store double ended cable on the Seagate Drive, and it
worked fine, but both the Seagate cable and the Dollar cable
would NOT run the harddrive if one of the two ends was not
plugged in - I tried both computer USBs, and various Powered
Hubs. This means that instead of using "NEW", Modern
"Low Power" harddrives, Seagate was using OLD, power hungry
harddrives, and had to CHEAT just to get enough USB power
to run them-- this is VERY Dangerous-- In my case there are
USB outlets from the Computer on one power supply, an EXTRA
 USB card with USB outlets in the PCI slot, and a stack of three
USB HUBS, each with a separate power supply!- If you plugged
in the "SEAGATE" USB cable into DIFFERENT HUBS on your
desktop, you would SHORT out the +5 Volt REGULATED power
supplies, or worse, SHORT OUT the Motherboard USB +5 Volt
Power rail and blow up your computer! Furthermore, there is no
reason that you could not, following Seagate Logic, buy 4 dollar store
USB cables, and cut each in half, with 8 ends, and wire them all
together, and plug all 8 into a computer. This would give you 8
times as much power as a single USB plug... As I stated, even large
International Corporations VIOLATE USB standards! You can
download the actual USB STANDARD details by clicking on:
Hundreds of cheap USB devices such as LED lights, Fans, and
even a USB mini-Beer refridgerator, are in the stores, but
many of these devices should be viewed with caution!

    Another way to get power would be a typical
WALL ADAPTER. Since many cell phones, iPODs ,
and devices use a standard +5 Volt supply, you can
get an adapter at hundreds of retail outlets such as
Drug Stores, grocery stores, general stores such as
Wall Mart etc. These +5 volt adapters may have a
standard mini USB plug on the end, or a special plug
designed for just one cell phone, etc. The END on
the plug does not matter, and since all you have to
do is cut the cable, separate the 2 power wires, and
use an electrical meter to find which is +5 volts.
Typically the wires would be black and red, with red
as the +5, or white and red, again, red is +5, but,
always check with a meter BEFORE you wire into
your circuit board!
       Finally, you can use almost any wall adapter
you find at any clearance bin in any store, typically
$1 to $2, that outputs DC volts from 6 volts to about
about 12 volts, by adding a single voltage regulator
chip called a 7805. This chip takes in higher voltages
and puts out a steady +5 volts. Since the small circuit
board, with a few LEDs uses tiny amonts of power,
almost any power supply wall adapter above 6 volts
and about 300 MilliAmps or 0.3 AMPS rating would work.
Higher Amperages make no difference and can be
used, such as 800 milliamps, 1000 milliamps ( One
Amp), etc. as long as the voltage is between 6 to 12
volts.The higher the voltage going INTO the 7805,
the more heat is generated, so the closer to +6 volts
you use, the cooler the chip will run. There are about
6 different types of transformers typically used, each
with slightly different output "characteristics", and I
will review these later. For now, the main features to
keep in mind are DC ( Direct Current, like a battery as
opposed to AC, Alternating Current, like a 110 Volt
wall outlet in a house ), and the voltage ( Like 5 volts,
6 volts or 9 volts ) and the AMPERAGE, like 300
milli Amps, or 1.0 Amps.
  ALSO USED by many devices that connect to the
parallel port, such as chip Programmers, is the common
+ 9 VOLT battery. If you are powering the first, simple
parallel interface, with only a few electronic parts on it
this is a FAST, easy way to get started without too much

High quality 9 Volts use 6 AAAA batteries inside. Lower
quality batteries use square slabs piled in a stack of 6.
ALSO, using AAA, or AA, or C or D sized batteries,
which are available anywhere, you can string 4 batteries
to make 4 x 1.5 Volt = 6 VOLTS, or 5 batteries to make
7.5 Volts, or 6 Batteries to make 9 Volts -- all of which
will power a 7805 to make REGULATED, +5 Volts!
Although using more batteries to make a 9 Volt total in some
ways "wastes" the excess electricity over +5 volts, it lasts
longer since, as you use the batteries, they slowly drop in
voltage from 9 to 8 to 7 to 6 etc. With a total of 9 to start out
with, there is room to drop. If you make 4 batteries into a
6 volt total, there is no room to drop down- 6 Volts is barely
enough to work in the first place, and as soon as the voltage
drops the 7805 will quit, since "it" needs some voltage over
5 volts in order to work. It will, however, work with only 4,
which is a fast, inexpensive start, but for a lot shorter time.
Note that the BIGGER the batteries, like "D", the LONGER
the 7805 will power the interface. ALSO NOTE: you can
use the TOP from any old 9 Volt battery to make a new
connector to your interface- just solder it onto 2 wires!
Just check which is Positive and Negative, since they are
opposite on the connector, to the battery! ALSO: if you
make a device that needs a LESS BULKY battery, you can
take apart the 9 Volt, usually by cutting the steel straps in half
and then use the thin AAAA batteries wired together, separately,
even in different locations in your device, soldering to the strap
ends. You can use any amount as well- 1.5 Volts with one,
3 Volts with two, etc. right up to 9 Volts with 6 AAAA's.

Now, if you plug in the printer cable on the back of the
computer, you can SEE the effects of putting in Zero's
and One's ( 0 and 1 s ) in the memory location 378 (hex).
The 8 LEDs will turn on and off the same as the Zeros and
Ones in the data memory location. This is an excellent way
to start programming and experimenting with the computer
as a robot controller.


There are general rules when using " logic " chips.
1/ All pins used as " INPUTS " must be wired to
       a +5 volt ( "high" ) or a Zero volt ( "low " or ground).
2/ Supply +5 POWER to the chip to run the circuits
     inside the chip, and Ground, or Zero Volts to the
      chip Ground.
3/ The OUTPUT pins do not " have to be " connected.
4/ You should not apply +5 Volt "logic" data to input
    pins, if the chip's +5 volt POWER is not connected.
(Note that some manufacturers have added safety resistors
diodes and capacitors etc. to protect the circuits inside their
version. It is just safer to always follow the simple rules.)

Rule 1, having all INPUTS going to a high or low, is needed
since if left unconnected, the circuits inside the chip
have no reference point and can "oscillate" or vibrate
randomly, damaging the circuits. The INPUT pins would
not be either Zero or +5, and would start rapidly switching
between the two, randomly. The chip will use huge
amounts of power, get hot, and quit. The Output pins,
on the other hand, are driven solidly to +5 volts or ground,
following the INPUTS, whether connected to another chip
or device, or not connected.

So, to use the 74 HCT 541, we connect the 8 INPUT pins
to the 8 data pins on the parallel port CENTRONICS
connector, connect +5 Volt POWER to the chip
power pin, and Zero ( 0 ) volts to the Ground pin, and
then connect the two ENABLE PINS that switch the
chip into the "Connect " mode -- so that the output pins
are " connected" to the logic ( +5 and 0 volt levels) of
the Input pins. Most "logic" chips ALWAYS have the outputs
actively "connected". This chip is special since the
outputs can be ENABLED or DISABLED by putting a
+5 or Zero on two " Logic Enable " pins, which are
wired together. When the LE pins are connected to Zero
Volts, or Ground, the OUTPUTS will show exactly the
voltages of the Centronics connector. When the LE
pins are switched to High, or +5 volts, the Output pins
act as though they are not connected to anything at all.
( This state is refered to as " High Impedance", pronounced
high Imp- EE- Dance, or called HIGH Z { High "ZEE"} )

Since we want to SEE what the contents of Memory
location 378 (hex) are, we will simply wire the ENABLE
pins permanently to GROUND or Zero volts at this

So, at this point, we solder wires from the 36 pin
Centronics connector, to the 74 541, and solder
wires from the +5 and Ground ( Zero volts ) of the
internal computer wiring, to the 74 541 Power
and Ground pins. Then, we wire the OUTPUT pins
on the 74 541 to the 8 resistors and 8 LED lights.

Some Centronics conectors have a removeable
cover, while some are moulded solid in plastic.
In order to gain easy access to the pins, I have used
a pair of pliers to bend the metal cover away from
the pins on the 1 to 18 pins. This is fast and crude,
and uses easy to obtain tools.

The Pins we are interested in are labelled below:

Finally, the entire 8 LED display is wired to the
74 541 Chip and the Centronics connector
as shown here. NOTE: some people have had to
lower the resistor to 120 Ohms to get the LEDs
to light up enough to see properly, depending on
which of the thousands of different LED they used.

To wire all these parts together on something
solid, I use a piece of cardboard. I fasten the
centronics to the cardboard with electrical tape
and a piece of wire wrapped around. The chip
is set on the cardboard and the pins are marked
where holes are punched through the cardboard,
and the chip is set into the holes. Holes are punched
into the cardboard for the resistors, and the LEDs
as well. Then each part is wired together.
( Note that pre-drilled blank circuit board can be
used instead of cardboard, but this material is
difficult to find, and is often pre-packaged at
very high, and unreasonable, prices. I have seen
a 6 inch square of perfboard for over $18,
plus taxes, which is more than the cost
of the electronic components!! This is unreasonable
for a 10 year old kid to pay for something
not absolutely needed.)


After you put all the chip pins through the cardboard,
and put the LED pins and resistor pins through holes
in the cardboard, it is best to SOLDER all the ends and
pins separately BEFORE you solder them together.
If you pre-solder all the wires and pins, then to connect
them, it takes one second of heat and they are well soldered.
If you try to take two pieces of bare, oxidized, metal, and
heat them up so that they both are hot enough to melt
the solder, then you will over heat them both, and over
heat the solder, and you can burn off the FLUX, making
a difficult connection, with black debris, and poor solder.

  Again, to put two pieces of wire together, pre-solder
( called " tinning" ) the bare ends BEFORE you join them, and
they are coated with fresh, shiny solder, so they will connect
easily with just a touch of the hot soldering iron.. Even the
Centronics connector should have the gold connectors pre-
soldered before connecting the wires. This will make the
wiring fast, reliable and solid.
NOTE - beware of instructions that tell you to heat the
metal parts until they are hot enough to melt the solder!!!!!
WRONG. I just saw on the web, soldering instructions
which were horrid, stating to heat the tiny metal parts of
chips until they melt the solder and stating never heat the
solder first - heat the metal first --. I have seen this mistake
over and over again, and there is a reason for it - This method
of heating the metal parts 'first' is carried over from the
1940's when unskilled workers were assembling tube
radio type parts on huge steel platforms. They would melt
shiny solder on top of huge wires and metal parts and
result in a " cold solder" joint that appeared ok, but was
not melted enough to bond the parts together. Today the
opposite is true. Heat the solder FIRST, putting the tiny
solder wire between the tip of the soldering iron and
the electronic component. When the solder melts, it
conducts the heat from the tip to the tiny metal part
completely and quickly. If you put a hard, dry tip on a metal
part, such as the metal pin on a chip, the tip only touches
in a tiny area, and you will take far too long to heat it
up. The idea of putting a soldering tip on a metal part until
the metal heats up, and then add solder is great for putting
copper and brass pipes together - this is the only way you
can do it, but you also have to use ACID solder and you
must use sharp wire brushes to shine the brass and copper
first. I have seen this mistake being taught over and over
again, and am horrified to see it in print on the web -
DON'T heat the metal parts hot enough to melt solder ! !

Here is a quote on the web for " Engineering Students " in
Minnesota, dated Dec 2008!
"" How To Solder 1. Heat the connection (NOT the solder) for
a few seconds with the hot tip of the iron. 2. Leave the iron
in place and apply a SMALL amount of solder from the
opposite side of the connection as the iron. ""
I can't believe it! - Tiny little metal pins on Integrated circuits
and tiny parts would be destroyed with this method, especially
in the hands of inexperienced, first time assemblers!! This method
was obsolete 25 years ago, and it is still being TAUGHT today!
Whomever is TEACHING this, obviously has never actually
soldered today's tiny components, but rather, is just copying
something out of an old, incorrect, obsolete, textbook!
In the picture below, if you heated up the bare wire and PIN 1
until they were hot enough to melt solder, you would turn
the insulation on the wire to charcoal, and blacken the teeny
PIN 1 to the point where oxidization would repel solder!

"USE" the solder to carry the heat from the tip of the soldering
gun or pencil, to the part quickly. BEFORE you connect two
parts, melt solder on both parts of the connection. THEN,
when you touch the two parts of the connection together,
you lightly heat the pre-coated, new, shiny, solder, and
instantly remove the hot tip. The wrong way, above, has you
heating the raw, oxidized, dirty, metal, blazing hot, and then
adding solder on top! ( And we wonder why space vehicles
dissappear over Mars ! ) NOTE THE SIZE OF THE WIRE,

If you look at the RED CAPACITOR in a typical circuit
that might be found in 1950, you see 2 big GOBs of wire
where the capacitor leads wrap around the transformer
under them, and notice one lead going left to a huge tab
of the METAL CASE. This type of connection would
require HUGE amounts of heat to melt solder, using the
soldering gun shown in the picture. NOTICE as well, a
more modern chip placed on the top of the picture, to
show the difference in the size of the pins to be heated.

The 1950's "pin" takes over ONE-HUNDRED times the heat in order
to melt the solder on the pin, compared to the 1980's pin, and yet, the
IDENTICAL instruction is often given on how to solder them! ! 

TINNING -When you first use a new soldering iron or
gun, you must cover the tip with new solder and flux,
and try to keep this layer shiny while you work. I
regularly wipe off the tip and re- " TIN " or coat
the tip and keep the flux a golden clear brown
colour. If the FLUX becomes opaque and dark
brown or black, the tip is too hot and dirty. Cool
down the tip, and re- apply a new coat. The typical
method for keeping a tip clean and shiny is to use a
wet sponge and wipe the tip regularly. You can
use a kleenex as well if you are careful, and always
IMMEDIATELY apply a new fresh coat of solder and
flux so that the metal of the tip does not " RUST"
or oxidize. Since most soldering PENS have NO
heat regulation circuit, you will have to constantly
unplug and re-plug in the PEN as you work to keep
the pen from getting too hot. You can buy a light
dimmer, typically a solid state switch mode box for
a table lamp with a dial, which allows you to turn
down the power, and expensive, high- end soldering
"stations" have a dial, and even a thermometer to
regulate the temperature. A typical cheap soldering
pen will burn itself out in a few hours if left plugged
in - the tiny heating wires are the diameter of a hair,
and in a tight coil around the pen, and not designed
for continual high heat use. A soldering gun can
be regulated by pulling the trigger switch on and
off as you work, and has the advantage in that
every time you set it down, it is OFF, and it QUICKLY
gets hot when you need it - the pen has to sit for
5 or 10 minutes before it gets hot. As well, the pen
can take 10 minutes to cool after being unplugged
and if accidentally touched will burn your skin


In the diagram above, I have only grounded the bare
minimum of pins needed. Grounding, or SHIELDING
the wires and the wire bundle, is needed for HIGH SPEED
switching of the +5 volt and ZERO ( 0 ) volt signals. As I
stated earlier, the first old PC computers ran at 6 million
times a second - so that the wires could change from +5 to
zero volts, 6 million times in a second... On a printer cable
this digital switching makes " noise " like a radio broadcast
and the switching on one wire can interfere with the wires in
the cable next to it. Because of this, there is a separate ground
wire for all 8 data lines, and a ground for a braided SHIELD
all around the cable to stop intereference. The Diagram below
shows all the grounds. In the early days of the PC, all the
grounds were CONNECTED TOGETHER to save wiring
inside the bundle. Later, a new standard called IEEE1284
(Pronounced EYE-Triple- E Twelve Eighty Four ) was made
with each wire separate, so that the cable was better and could
be made LONGER and still have no interference at higher speeds.

ALL the ground pins can be wired to " GROUND " or Zero Volts
at some point, and as we add transistors, relays, resistors, and
more LEDs, this would be a good idea. Since the program used
in BASIC is 6,000 times slower than the CPU ( Central Processor
Unit or the Processor chip - the Intel 8088, 80186, 80286 etc. )
the worry about signal interference, for the moment is absolutely
minimal !

The pin numbers are shown on the list above, and can be all
wired together - on many old cheaper cables, they already were
wired together, and depending on what cable you happen to
to use, they may already be wired together inside...
If you use an old, cheap, typical cable, the odds are that all
the grounds are connected to a single wire in the cable, and
that there are only 18 wires connected to 25 pins, with NO
outer shielding at all. For this project, it is all that is needed.
If you use a newer, expensive " IEEE 1284 " cable, you might
find gold plated contacts, and 25 separate wires, a separate
grounding wire, a separate braided outer coating of wire wrap,
and a wrap of grounded metal foil around the cable! The newest
cables have the 8 DATA signals and the grounds, wired as
twisted pairs, inside a separate, double shielded cable, and the
rest of the wires wrapped around that, inside another double
shielded outer cable!


              HOW TO Page 1       CLICK HERE

   (page 2 will open in a TAB, just close TAB to return)

   (page 3 will open in a TAB, just close TAB to return)

   (page 4 will open in a TAB, just close TAB to return)

If you CANNOT see the toolbar with the MENU on the LEFT
side of this page, using a home computer or laptop, or, if you
are on a CELL phone and cannot see or click on the menu at
the top of the screen, then you can, as an option,           CLICK HERE
go to the correct HOME PAGE,    www.kidbots.com    

MATH                   CLICK HERE

HOW TO              CLICK HERE

TYPES                  CLICK HERE


IMAGES               CLICK HERE

Robot Cartoons      CLICK HERE

Robots                    CLICK HERE

About kidbots         CLICK HERE
Kidbots.com is a Free website, with Free
information, on how to USE  Free computers
to make Free ROBOT controllers and
Free ROBOTS for kids. NOTE: it's FREE.

DUSTYGRAVES Dusty Graves dustygraves.com dustygraves.com DUSTYGRAVES.COM robin dusty graves ROBIN DUSTY GRAVES robindustygraves ROBINDUSTYGRAVES robindustygraves.com robindustygraves.com ROBINDUSTYGRAVES.COM robin@dustygraves.com ROBIN@DUSTYGRAVES.COM kidbots.com  kidbots.com KIDBOTS.COM ROBINDUSTYGRAVES@KIDBOTS.COM robindustygraves@kidbots.com GRAVITATIONALRESEARCH GRAVITATIONAL RESEARCH gravitationalresearch gravitational research GRAVITATIONALRESEARCH.COM gravitationalresearch.com  gravitationalresearch.com

robin dusty graves
robin dusty
dusty graves
kid bots