I am surprised to find what gets hits and what dosen't.
My 'led on glass' I thought would be in the millions by now.
And my 'poor mans solder pot' is doing well and I never
thought this would even take a hit. The 'led on glass' is
quite artistic. To see just a photo and not the real thing
diminishes the project. So not to let the concept die,
I came up with 'time square'. Which is nothing more than
my reader board folded into a square. To see just a photo
dosen't show the movement as the displayed message
speeds around the corners. And the angles of perspective
as the display moves to and away from you.
I apologize for this post being so large.
I don't need recognition at my age. OR jump up
and down saying 'look what I did'.
I believe anyone with minor skills and determination
can make this cube. I don't use any expensive tools
other than a table saw and that is only for miter
cuts in trim. So a miter block and hand saw would work.
My instructions try to explain the circuit and
procedures I use. I have used common components
but I know not everyone uses the exact stuff I do.
So I try to explain how my stuff works so you
can change to your stuff. I tried to be precise
and not vague. This makes this way TOO LONG, so I
made this in 2 parts. I think anybody with minor
skills can make this...but not overnight.
Step 1: Description of Project
This square stores 7 messages, time, date,
and temperature. Without a computer...all self contained.
I use pro-mini, leds, PC boards, ir sensor,
DS1302 rtc, generic temperature sensor, epoxy,
door case trim. The project should take 30-40
hours not including the pc boards. I have some steps
that make the project easy. The finished 'BOX'
takes a lot of time, so I have a easy version.
Basic solder skills, patients, and good PCs will help.
Because I wanted the fewest leds to mount
and solder I have a 5x5 array. Not a standard 8x8.
This means to modify my sketch for
another clock chip you can't use any libraries. They
all use 'char' varriables. I also use a 'scan' for my
display instead of x y coordinates. I know my sketch is
a mess. But it works in over 60 models that I have made.
It is one of those sketches that you start out with
a few lines. Then add this and that over two years.
My sketch dosen't crash and preforms well. I had a hard
time deciding to have just a clock/temp square. But I
used this sketch because it's proven and the user can
display only the featuers they want. Before you decide to
make this you might download the instruction manual.txt
to see if the features are what you expect.
Sorry, this project is only for anyone who
can make PC boards and an early warning, invert
the nine 74hc595 ics. (more later)
Step 2: PC Boards and Tips
I have pdf of the 4 PC boards. The photos show a PC
for the clock. The PC is used in other models.
So this clock will use only a few of the connections
on the PC.
I use popular PC 3x6 inch. The thin line near the edge of
the led grid (not the outline rectangle) is very important
because this line is the outside dimention of the finished
square. So make sure this is part of the finished PC board.
You need one PC with rows ic (3ea-595) and three PC with
columns (2ea-595) for one square.
Some hints for making PC boards. I have the worst printer
a 'brother' $99 special. I hear the HP brand laser, around $140,
ink is better. In over 2 years I found that the best results
are to print on a dry crisp day, not rainy or damp. To
copy the ink to the PC soon after printing. (1-3 days)
I tried many many many papers and have good results with
'EVERY DAY with RACHAEL RAY'. The second best paper was the
yellow china paper but if it gets too hot you could NOT
remove it from the PC. The last but best step is to use
foil ink. Arts and crafts use this in many colors to
overlay ink on paper. It seals the ink so etching won't
seep through and make those tiny holes everywhere. Rub the
PC with your finger and water to remove any paper fibers
before applying the foil. Color side out, drab side against
ink on the PC, laminate or iron. And last....thanks for
all of the posted muriatic acid and bubbling. I know
the real answer to tiny holes is a better printer and ink.
But if you have a sure fire...proven way to make a
PC without the tiny holes without using an expensive
laser printer, please post a comment here.
Step 3: SHAPE PC Boards
If your PCs are good then they need to be shaped.
I grind the edges to a 45 degree angle on the
cement and finish on 220 sandpaper on a flat surface.
The thin line next to the led grid is the actual
edge of the finished square. All 4 PC boards must
be this size to make a good square with 90 degree
corners. Then cut to length. If you do not make
a tall enough bottom case, then recess for the
7 pin male socket now.
Step 4: INSTALL COMPONENTS
Sorry, but to get flow and patterns correct the
595 ic pins 1-7 must face the leds or have foil
runs all around the board. So you MUST INVERT the
74hc595. I have done this hundreds of times
without damage. FIRST mark the pin 1 dot
onto bottom. Then, on a hard surface, invert
the ic and hold it flat to the surface. Now,
one leg at a time, push that leg to the surface.
I use a small flat tip screwdriver.
Clean the PC and dab on flux.
I install the ics first...less stuff in the way.
Then the smd jumpers. I like my zero ohm jumpers
upside down so at a glance I know they are not
resistors. There are 12 jumpers on the row PC.
and 9 on the column PC. Both have 'WIRE' jumpers
to add later when making the actual square.
The 3 PCs without the row have only C-C and
L-L wire jumpers. You can add them now using
Step 5: THE LEDs
Your display is only as good as you place the leds.
If just ONE led is off center it will stick out
as the display scrolls by. I like to use 805 leds.
They have a green mark to go upward. (negative
or cathode) This goes upward. I have one reel
that was marked wrong and had to toss my PC.
Please check polarity first. Negative is up
on my grid. (test= 9v batt and 1k resistor...
when lit the negative goes up)
I start from the bottom and work 1 row at a time.
I solder tin only lower pads. Place the led and
solder the lower pad. I only solder the upper
led pads as a group. This (one pad side) allows
for small position changes of out of place leds.
The display is seen from all sides and angles.
If on a desk, most people will view this from
a downward angle. When placing the leds on the
PC the leds want to float upward in the solder.
This changes the viewing angle. So push lightly
downward on the led so it is FLAT to the PC. This
is even more important then having the leds in
a nice stright row. I have another reel of leds
that are off center and the display is almost
blocked out when viewed from the top. Look closely,
the led hair contact should be in the center.
[.] no [-] ok
Last... the solder needs to be flat too.
If a large blob forms on the pad, it will block
the view angle. Whipe hot solder with a Q-tip.
If all leds are stright and flat then I solder
the upper pads. I use standed wire about 36 gauge
harvested from shilded wire. And later I use
about 22 guage harvested from stranded ac wire.
With 36 I tie the negative rows together. The
led itself holds the wire up from the PC and not
contacting with the foil runs. You will paint
this so eventually this bare wire will be ok.
The TOP row has the foil run. Just do the other
four rows. Keep the solder blob small. I also
like to run the wire strand through 600 grit
sandpaper so it is good and shiny and solders
easily. THREE MORE TO GO.
Step 6: PRO-MINI and Clock
I use a female 7 pin connector. This is soldered into the
pins 10,11,12,13 of the mini. End pins are bent upward
and soldered to ground (left side) and Vcc (right side).
Pin 9 goes next to ground. See photos. Add 2 50k pull
up resistors to Vcc and pins A2 A3. Add the clock PC to
pins 6-7-8 and 5 for the IR sensor (if used).
The clock PC has other pads, just use the ic
and cap layout. Isolate (cut foil run) on
clock PC (mini 5) for ir sensor.
Vcc and ground to IR and clock. I add the keypad later
because it gets in the way but you can tack it in now
just to set the clock.
Thermocouple on pin A3 to ground.
I downloaded the sketch into a mini. Even without clock,
keypad, and temperature sensor it will display. You can
use this as a quick check on the row PC with the jack
just to see if you are on the right track with the
project. You should see this display (scrolling) and
before the temperature averages a reading there will be
here is the display...
1C::7C twirl FRI 1C/7C/20CC **1****.... /F'--\
:: is AM: or PM:: twirl is seconds in motion (this is a
display motion and NOT a clock function)
then date mm/dd/yyyy
then 1-7 default stared messages
If you did build the full mini with clock,sensors and
keypad you will see about the same until you set the clock
and enter a message. I like to edit a message with all
squares to see if all the leds work. This is menu,edit,
msg1,blinking cursor,down arrow about 16 steps,then
with square in the cursor enter about 10 times, then
menu to save and exit.
Some help on the clock:
I had some clocks that would not start running.
They would load data but not run. Turns out the
crystals are very picky. Must use a 6 pf load
crystal. The backup cap is used instead of a
battery. Any size cap from 300-500mfd will keep
the clock running for about 2-4 hours when the
electricty is off.
RTC NOTE: the DS1302 is available on a pc with
battery. My sketch will NOT work with a battery.
It wll burn up the rtc and mini. Remove the
battery and install a 300+ cap. OR modify the
sketch by blanking // charging code near line 440.
Step 7: The SQUARE
Now I put the PCboards together using angle steel and
clothes pins. I solder the tops with 22 guage stranded
wire from average ac wire. Solder one side and position
the edges...pull down and solder the other side. Then
the bottom of the same corner. I do just the top+bottom
around the whole cube. The wire will give a little for
minor adjustments. Then solder the main foil runs at the
bottom. Cube gets slightly stiff but is still loose.
Last I solder the thin 4 row wires and add a fifth wire
to the top row. Last I solder the wire jumpers.
For theese jumpers you need insulated wire.
jack is 1-2-3-4-5-6-7 1=Vcc 7=neg
on row PC.
jump C-C L-L D-jack2 jack1-Vcc
jack5-btm3 row ic jack6-btm6 row ic ||-||
|||-btm2 col2 ic
8 wires and 5 on bottom each corner and 6 top...
1-top copper 5-led rows
on other 3 PC jump C-C L-L
and 5 bottom corners and 6 top corners
If all looks good I GOOP (E6000) the inside corners.
Use a flat screwdriver and fill in the gaps.
Stand upright and place on wax paper. This glue
is the best stuff EVER. Toss your epoxy, super glue,
sillicon, hot glue gun and elemers. REALLY, this
is GREAT glue.
Let dry overnight.
I do another mini-pro connect to see if all
leds light up and move correctly.
I must have put you to sleep by now....
My next steps are in part 2 and I talk
about the temperature sensor. Making the
keypad and IR remote features. Tips on
construction of the box. Sillicon casting
of marble like cap. Epoxy casting of leds
in the case. And trouble shooting display