Fritzing session! I searched a bit further and found a more
recent version of that file and it worked just fine. Lesson:
You might have to mess around a bit to find these parts,
and they might not work. (This is just one of the joys of
open source design.)
Now, notice in Figure 16 that the part selector box
shows ‘MHz’ which probably means the author of this
part reused an image (since the price is right, we won’t
fault him). The part itself looks like the watch crystal we
will be using, so we drag it over to the DS1307 and drop
it onto pins 1 and 2. Unfortunately it covers the IC and
blocks most of the breadboard connections for pins 7 and
8, so let’s flip the part around 180º as shown in Figure 17.
The Inspector Window
■ FIGURE 15. Typical operating circuit.
have proven necessary often enough in the past that I just
throw one in for every digital IC and sleep better.]
So, based on Figure 15 and the datasheet specifying
the crystal, the next thing I wanted was a 32.768 kHz
watch crystal to use on the breadboard. So, I imported
“CRYSTAL – kHz.fzpz” as before and it almost killed my
■ FIGURE 16. Select and move the crystal.
Boy howdy! Am I embarrassed! I was writing this
tutorial on the fly while learning to use Fritzing, and after
all that rigamarole about how to import a DS1307 since
they only have a DS1302, I find I was wrong, wrong,
You select a DS1302 from the
parts bin and drop it on the
breadboard, then (as shown in
Figure 18a) you open the ‘variant’
dropbox and click on DS1307.
Voilà! You have the correct part.
We repeat this pattern when we
add the resistors (shown in Figure
18b rotated as with the crystal).
The default is 220 ohms, but you
can click on the resistance dropbox
in the resistor’s Inspector window
and select 2.2K, which changes
both the value and the color
If an exact part you want to
use is not in the parts bin, you may
find a similar part can be modified
in the Inspector window to match
your needs. If the exact part you
need just isn’t available, the folks at
Fritzing will create a part for you
(for a fee, of course).
Back to the
■ FIGURE 17. Rotate the crystal.
We connected the resistors
between pins 7 and 8, the upper
breadboard row that we will need
to connect to VCC, but let’s get all