Andrew O'Malley DOTKLOK User manual

D O T K L O K Assembly Instructions
1 January 2015
www.technoetc.net/dotklok / www.andrewomalley.etsy.com
Required tools / materials
•soldering iron
•solder
•wire strippers
•flush cutters / wire nippers / diagonal cutters
•multi-bit screwdriver
•small / needle-nose pliers
O tional tools / materials
•helping hands
•solder fan / defumer
•multi-meter
•solder sucker/vacuum
•solder wick
•lint-free / microfiber cloth
PART I: PCB ASSEMBLY
Your final PCB will look like this, once fully assembled

All parts sit on the top of the board and are soldered from the bottom.
Please refer to the bill of materials (BOM):
www.aomalley.org/dotklok/files/DOTKLOK_bom_illustrated.pdf
for an illustrated parts list.
Take care when unpacking the kit components, there are several small parts,
and no extras have been provided. TIP: the foam housing for the LED screen
makes for a handy parts tray while assembling DOTKLOK.
If your PCB is labeled “DOTKLOK . ” you will need to solder a wire
across the JP pads in order for the board to work with the power supply
included with your kit. Although a specific wire has not been included for
soldering this jumper, you can can use one of the cut-off leads from a
resistor or capacitor soldered in the following steps.
2
Solder a wire
across JP

. Solder HDR (six pin, right-angle header, no polarity), with long pins facing
out from PCB.
2. Solder SK2 (small, 8 pin chip holder) at IC2 and SK (large, 28 pin chip
holder) at IC , matching the notch of the chip holder with the notch on
the PCB diagram.
3
Note, notches
(circled) must match
by facing
left
Note, long pins
facing out from
PCB

3. Solder Q ( 6Mhz crystal, no polarity), C and C2 (22pF capacitors, no
polarity, marked 220). If needed, bend leads to hold components in board
during soldering; once soldered, trim excess leads from back of PCB.
4
SK2 (small 8 pin
chip holder) at
IC2. Note, notch
(dotted circle)
faces left
Bent leads best
hold
components in
while soldering;
Excess leads
should then be
trimmed
SK (large 28
pin chip holder)
at IC . Note,
notch (dotted
circle) faces left

4. Solder R3 ( 0k resistor, no polarity, colour bands: brown-black-orange)
and C5 (0. uF capacitor with long leads, no polarity, marked 04), trim
excess leads from back of PCB.
5
Q ( 6Mhz crystal)
with C and C2
(22pF capacitors)
R3 ( 0k resistor)
and C5 (0. uF
capacitor)

5. Solder R and R2 ( k resistors, no polarity, colour bands: brown-black-
red) and C3 (0. uF capacitor with long leads, no polarity), trim excess
leads from back of PCB.
6. Solder R4 and R5 (2.2k resistors, no polarity, colour bands: red-red-red),
trim excess leads from back of PCB.
6
R and R2 ( k
resistors) and
C3 (0. uF
capacitor)
R4 and R5 (2.2k
resistors)

7. Solder CR 220 (coin cell holder). Note, coin cell holder must be placed
so that the square edge points left.
8. Solder X ( 0 position screw connector). Openings MUST face outer
edge of PCB.
7
CR 220 (coin
cell holder). Note,
square edge
points left
X ( 0 position
screw connector)
opening MUST be
placed so open
part faces outer
edge of PCB as
shown in the red
circle. The
connector should
NOT be placed
with the closed
end facing the
outer edge (as
shown in the
crossed out
picture)
FAIL

9. Solder C4 ( 0uF olarized capacitor), making sure (longer) positive lead
(black side of cap) goes into square (left) pad. (Note: the negative side of
the cap is marked with a silver/grey stripe); trim excess leads from back
of PCB.
8
X ( 0 position
screw connector).
Note, open part
faces outer edge
of PCB
C4 ( 0uF
capacitor) is
polarized. Longer
(positive) lead is
marked by the
black side; shorter
(negative) lead is
marked by the
grey side

0. Solder HDR2 (two separate 8-pin upright headers) Short leads MUST go into
the board for soldering; taller leads MUST face upright, coming up from top of
board. Ensure headers are soldered so they are straight and upright. You do not
want them to be crooked.
9
C4 ( 0uF
capacitor) longer
(positive) lead
(marked by the
black side) MUST
go into the square
(left) pad on the
board
Short leads MUST
go into the board
for soldering

. Solder Q2 (32.768kHz crystal, no polarity). Important, push the crystal
ONLY half way down into the board. Solder and trim excess leads from
back of PCB. Then, gently bend crystal down against PCB to match
diagram on PCB.
0
As best as
possible, ensure
headers are
soldered so they
are straight and
upright. You do not
want them to be
crooked
Push the Q2
(32.768 kHz
crystal) ONLY ½
down into the
board so that half
of the leads can be
seen from the top
of the board

2. Solder CN (power jack). Insert so that jack is facing outward from board.
When inserting the component into PCB, the back and side leads can be
bent to better hold it in the board. Solder the leads to the edge of the
circular holes. It is not necessary to fill in the entire hole.
Once the crystal is
soldered in the
board, bend the
crystal down
against the PCB,
so it covers the
diagram on the
PCB
Place CN (power
jack) into three
round holes on
PCB (note these
holes are not
labeled on board).
Silver power jack
must face out
from board

2
Solder the leads to
the edge of the
circular holes;
note, the solder
does not need to
fill the hole, a
decent solder
connection just
needs to be made
Note how opening
is facing out from
board

Congratulations! You’ve now completed the soldering of your PCB. Your final
soldered board should look like this:
PART II: INSERTING THE CHIPS
. Insert IC (ATmega328) into IC chip holder. Ensure notch on chip lines up
with notch on chip holder. Make sure all pins are aligned. Note, chip pins may
need to be slightly bent with pliers to ease insertion. Then, gently press into
place.
3
Note, these
breakout pins have
intentionally been
left empty so you
can use your
creativity to add
sensors, extra
buttons, buzzers,
etc. to your
DOTKLOK
Note, notch on
chip

2. Insert IC2 (DS 307) into IC2 chip holder. Ensure notch on chip lines up with
notch on chip holder. Make sure all pins are aligned. Note, chip pins may need to
be slightly bent with pliers to ease insertion. Gently press chip into place.
4
Notch on chip
must align with
notch on chip
holder. Make sure
all pins are aligned
before gently
pressing the chip
into place
Notch on chip
must align with
notch on chip
holder. Make sure
all pins are aligned
before gently
pressing the pin
into place
Note, notch on
chip

3. Insert coin cell into coin cell holder (CR 220), by slipping under metal tab.
The “+” side must face upward when placed into coin cell holder.
5
Note, writing or “+”
side of coin cell
must face upward
when placed in
coin cell holder

PART III: TESTING THE PCB AND SCREEN
You are probably anxious to test your newly populated PCB! However, before
powering everything up for the first time, it is wise to do a visual inspection of the
bottom of the circuit board.
III.1 Checking soldering
Start by looking for solder bridges -- places where excess solder might bridge
between adjacent connections, making unwanted electrical connections.
If you find any solder bridges, they are easily removed with the soldering iron,
though sometimes a solderer sucker/vacuum or solder wick may be needed to
remove larger amounts of excess solder.
If you have a multi-meter, now would be a good time to ensure there isn’t a short
between power (5V) and ground (GND).
You can test for continuity (or resistance) across the 5V and GND pads of the
prototyping area; ideally, you want to find no continuity or a very high resistance
(approx. 230 KOhm).
6
Note, inserted coin
cell slips under
metal tab with the
“+” side of the cell
facing upward

If you do find a short circuit, you will need to hunt for and remove this short
before proceeding; otherwise you will damage the board, the screen, and/or the
power supply.
III.2A Testing the Board & Screen – screens with chi s on FRONT
The following ste s are for the original Sure screens which have the chi s
and selector switch on the same side of the board as the LEDs. (The ste s
for the new Sure screens are in section III.2B )
A) With the screen facing right side up, so the LEDs are showing, ensure CS ,
(pin of SW ) on the screen is flipped to the right/on position and pins 2, 3,
and 4 are all flush left.
7
Test for continuity
(or resistance)
across the 5V and
GND pads of the
prototyping area
Ensure CS , pin
of SW , on the
screen is flipped to
the right/on
position and pins
2,3,4 are all flush
left

B) Now, flip the screen over, face down, so you see the solder connections and
electrical sockets.
C) To attach the ribbon cable to the screen, place the ribbon cable so the
connector pins are facing downward and the red side of ribbon cable is at the
top. Then, insert the notched connector into the left socket (BR2) of the screen.
8
Screen placed face
down so solder
connections and
electrical sockets
show
Connector pins
must face
downward with the
red side of ribbon
cable at the top.
The notched
connector goes
into the left socket
(BR2) of the
screen

D) With the PCB placed to the right side of the screen, connect the other side of
the ribbon cable to HRD2 on the PCB, ensuring the bump on the ribbon cable
connector aligns with the HRD2 label on the PCB. Ensure all the connector
wholes are properly aligned with all the connector pins. The red side of the
ribbon cable should be closest to the prototyping area.
E) You’re now ready to power the screen up for testing! Although the buttons
are not yet attached for setting the time or switching the animations, once you
plug the power supply into the board and plug the supply into the wall, the display
should show a simple time animation with hours and minutes. The DOTKLOK
may take a few seconds to start up, this is normal. A note about the power
supply: only use a 5V supply as included with your kit, input voltages greater than
5V WILL DAMAGE the board!
9
The red side of
ribbon cable at the
top.
The notched
connector goes
into the left socket
(BR2) of the
screen
Connect the other
side of the ribbon
cable to HRD2 on
the PCB, ensuring
the bump on the
ribbon cable
connector aligns
with the HRD2
label on the PCB

F) Once you’ve ensured your screen works properly, you can unhook the power
supply and remove the ribbon cable from the PCB. You should then use the
white zip tie to bundle one loop of excess ribbon cable.
20
Plug the power
supply into the
board and plug the
supply into the wall
The display will
show a simple
time animation
with hours and
minutes