SMILEY’S WORKSHOP ☺
■ FIGURE 19. Add a
■ FIGURE 18B.
■ FIGURE 18A. Inspector window.
the parts down before we flip the power switch.
We add a 0.1 µF bypass capacitor as shown in
Figure 19. Note that I chose to rotate the part by 45º so
that it wouldn’t block the pins that we will need to attach
to VCC and GND.
Now that we have all the parts on the board, we will
want to add the wires. Before we do that, we will want to
add an Arduino that will be reading the date and time
from the DS1307, and will be providing the main power.
We will also want to add a three volt battery for backup.
While we almost certainly would be using a coin cell for
the backup battery in a ‘real’ design, for this
drawing let’s just use a battery box with
two AA batteries since we have on at hand.
[Okay, I have one at hand.] NOTE: DON’T
BE TEMPTED TO SOLDER WIRES TO A
COIN CELL BATTERY TO USE WITH A
BREADBOARD – IT MIGHT BLOW UP!
Next, you will want to zoom out to
make room for an Arduino and a battery
box that you can find among the parts.
Drag them and drop them into the
breadboard window as shown in Figure 20.
Now we have all the parts, so let’s wire
it up. You’ll want to refer back to Figure 15
for this. First, let’s do the power and ground
wiring. Note that there are two power
sources; according to the datasheet, we
want + 5 volts on pin 8 and + 3 volts on pin
3 (for our backup supply). In Figures 21
and 22, we see that we can left-click the
cursor on a part’s connector, drag the wire
to the connector we want to attach to, and then release
the wire. Since this forms a straight line that might get in
the way of seeing all the wires on a board, we add a bend
(as shown in Figures 23 and 24) by first right-clicking on
the wire to get the ‘add bendpoint’ indication and then
left-clicking the cursor to grab the bend so that we can
move it to where we want it.
■ FIGURE 20. Add the Arduino and the battery box.
August 2012 57