■ FIGURE 5. Loopback test in
the Simple Terminal.
■ FIGURE 4. FT232R breakout schematic.
breadboard as shown in Figure 3, you can’t see which pin
goes where. I’ve sort of solved this by producing a Word
document with the table shown in Figure 3 that when cut
out and folded like a tent, has the pins labeled. You can
get the Word document in the Workshop21.zip.
The Loopback Test
After you’ve got your loopback hardware completed,
you can test this with the Simple Terminal we built in
Workshops 18 and 19.
Building The Breadboarduino
We will simplify our lives in this section by leaving off
■ FIGURE 6. Breadboarduino schematic.
the Arduino power supply section and using
only the power from the USB port.
Theoretically, we can take 500 mA from the
USB, but there are caveats that cause me to
advise using less than 100 mA. This should
be enough to do a Cylon Eyes type project, but probably
not enough to run motors.
Not all the parts in the figures are exactly like those
from SparkFun. I used several color wires and a longer
breadboard. Also, if SparkFun has an ATmega328 with a
bootloader, get that instead of the ATmega168 and
translate where appropriate.
When I built the section shown in Figure 7, I had the
upper black wire two spaces to the right and nothing
worked. Duh, running /RESET to ground tends to create
that symptom. I moved it to the position shown and
In Figure 8, the serial communication wires are in
yellow. You may need to put the paper tent label on the
FT232R breakout board to see where the TxD and RxD
go. REMEMBER: The TxD on the FT232R board goes to
the RxD on the ATmega (pin 2), while the RxD on the
FT232R goes to the TxD on the ATmega (pin 3). This
confuses a lot of folks, but
think about it for a moment.
The data being transmitted
from the PC through to the
FT232R is being received by
the ATmega. The data being
received by the PC through
the FT232R is being
transmitted by the ATmega.
Figure 9 provides an
enlargement of the section
containing the crystal and
■ FIGURE 7. Automatic
and manual reset.
Program For The
It is not my intent to
scare anyone with a code
listing, though I fear that