Hardware Reference
In-Depth Information
header with the notch indicated in the box. On the original Cobbler PCB, the notch
must be right next to the “21/27” label; on the T-Cobbler PCB, the notch must be
between the two large round holes at the T junction point. You need to get this right,
because if you get the notch backward, this will cause the pins to be reversed when
the cable is connected between the Cobbler and the GPIO pins, and the labels on the
Cobbler will all be wrong.
Soldering Reminders
Soldering might seem scary at first, but it really isn't very difficult if you're
careful and respectful of the iron. Keep a few things in mind:
• Solder, when heated, releases mildly toxic smoke. You should always
solder in a well-ventilated area.
• The soldering iron gets hot. Very hot. (The actual temperature varies
on the type, quality, and condition of your soldering iron.) It will burn
you if you touch the tip of the iron, so always hold it by the handle, and
don't lean in too close.
• Always assume a plugged-in soldering iron is hot and treat it that way.
Heck, we usually assume unplugged soldering irons are hot, too.
• Every soldering iron should come with a stand. Use it. This keeps you
from accidentally burning holes in your workstation, project, hand, leg…
• Keep a small, moist sponge handy, and as needed, use it to wipe off
excess solder from the tip of the hot iron. If the tip of the iron becomes
coated in solder, it will no longer work effectively.
• You don't need to put a giant blob of solder down to make a good con-
nection. When heated, solder quickly becomes a liquid and will flow into
heated connections. Just a tiny bit will do. Practice will help you realize
how much to apply.
Flip over the PCB, with header connector still in place, so that it is now sitting on the
header. You should see little bits of the 26 connector pins poking out from 26 metal
rings on the PCB. Press the tip of your soldering iron simultaneously against a pair of
the rings and pins. Hold it there for a few seconds to heat up the metal, and then touch
some solder against the tip of the iron. The solder will melt instantly, liquify, and flow
between the pin and the ring, making a complete connection.
