“Marquee” pattern of the Auto Cycle Mode.
(One of the things that we found extremely useful
when building the tree is to have a very quick check to
ensure that all of the LEDs are functioning. When power is
first applied on the tree, we run a special Power On Self
Test pattern that simply lights up all the LEDs for a bit over
a second and then turns them off. After that test runs, we
just launch into the normal sequence of patterns.)
If nothing happens, don’t panic. It is likely something
simple. First check the batteries. Are they installed with the
correct orientation? Do the batteries really have a charge?
Are the processor (U1 in the socket) and the Schottky
diode (D99) installed with the correct orientation? Are all
the transistors and resistors installed? Do all the transistors
and LEDs have the correct orientation?
If you get some of the LEDs lighting up, but not all of
them, then you likely have something amiss in the LED
display matrix or the row/column drive circuitry. Here are
a few hints to work through:
• One LED out: The most likely problem is that the LED
was installed with the wrong orientation. Find the flat part
on the side of the LED’s base. Is it aligned with the flat
part on the silkscreen? If not, remove the batteries and
change the orientation of the LED.
The second most likely culprit is a soldering problem
with just that LED. Remove the batteries and check for a
solder short on either of the two leads of the LED or for a
solder splash in the area. Re-touch the leads to ensure a
good solder joint.
• Four LEDs out: Have a look at the schematic. Are the
affected LEDs in one row (e.g., D1, D9, D17, D25 or D3,
D11, D19, D27)? If so, you likely have a problem with the
row drive circuitry. Remove the batteries and check the
drive components for that row (e.g., R1, Q5, R13, U1, pin
9 or (R3, Q7, R15, U1, pin 5). Again, check for solder
shorts on the leads of suspect components and re-touch
the solder joints.
• Eight LEDs out: Check the schematic to see if the
affected LEDs are in one column (e.g., D1-D8 or
D17-D24). If so, the column drive circuitry is the likely
culprit. Remove the batteries. Check the column drive
components for the affected row (e.g., Q1, R9, U1, pin 10
or Q3, R11, U1, pin 12). Again, check for solder shorts
and re-touch the leads of the components in question.
The only other functionality to verify is the USB
power. Remove the batteries and plug into a powered
USB cable. The tree should power up, light all LEDs for
about a second, and then move into the Marquee pattern.
If not, there are only three things to check. Is the USB
cable really powered? Is the Schottky diode (D98)
installed with the correct orientation? Is the USB
connector (X1) installed correctly? Check the leads of
these components for solder shorts and re-touch them.
PATTERN LIST
■ Auto Cycle Mode (the ■ OneColor
initial Marquis pattern ■ Star
indicates you are in this ■ Blinking
mode) ■ Swing
■ Glowing ■ Flashing
■ CycleDown ■ Drip
■ Fountain ■ OnOff
Decorations
Paint the top of the transistors with gold or silver
paint, add beads (use the via holes to tie them on or
hot-glue them to the board). You could even build a box
around the batteries so it looks like a present.
Mash the Button!
To turn on Tree 1.1, simply press and release the change
pattern button. This will cause the tree to power up and start
the Auto Cycle Mode to sequence through the pattern list.
While in Auto Cycle Mode, each pattern will be
displayed for about 30 seconds before it automatically
changes to the next pattern.
Turning off the tree is a two step process. Don’t press
the change pattern button for two seconds. Then, a single
press will turn it off.
Tree 1.1 has 11 different patterns in it. If you find that
you have a favorite one, you can use the change pattern
button to cycle through the pattern list and select a single
pattern to be displayed all the time. Each press of the
button will select the next pattern in the list. Once you get
to the end of the list, it just starts over again from the
beginning. Remember to press the button quickly or the
two second timing to turn it off will come into play.
Building on It
A lot of things go into making a simple tree, but the real
contribution to it is your own hand in building and decorating
it as a gift. Where else do you get to have your soldering
skills on display and put a twinkle in people’s eyes? NV
AUTHOR BIO
■ Dave, John, and Mark have been friends for over 20
years. They have worked together on numerous projects;
some for the day job and some for home projects. All the
projects involved hardware and/or software design for
embedded computing, personal computers, telephony
systems, and/or data networking.
A complete kit for this project can be
purchased from the Nuts & Volts Webstore
@ www.nutsvolts.com
or callour order desk, 800 783-4624.
November 2008 51
