Soldering Your First BeagleBone Joint - dummies

Soldering Your First BeagleBone Joint

By Rui Santos, Luis Miguel Costa Perestrelo

A breadboard is quite useful to prototype a design, but what do you do when you’re done testing? Keeping your BeagleBone project solely within a breadboard can lead to a couple of problems, such as your wires wearing out due to being kept in the holes for too long. Also, breadboards were built with reusability in mind. When you dive into a new project, you either discard your previous breadboard or buy a new one.

This practice is both tiresome and unnecessary, not to mention expensive. Finally, breadboards are huge bricks that are anything but practical in real-world applications. After you test and retest everything, it’s time to build something permanent. Using soldering, you can create your circuitry with the layout you desire.

A soldering iron gets as hot as 850 degrees F (454 degrees C), so you must always be sure to place it in the iron stand and be super-careful while you have it in your hands. Don’t touch the metal tip, and avoid touching other materials with it. If you’re a minor, make sure that an adult is nearby when you’re soldering. Don’t get too scared, though; just don’t touch the metal tip, and everything will be fine.

The recommended temperature for melting solder is 620 degrees F (326 degrees C). Some soldering irons allow you to choose a working temperature. If you have one of those irons, select 620 degrees F, as this is hot enough to melt the solder.

Let your soldering iron heat for a couple of minutes. To check whether your iron’s tip is hot enough and ready to use, touch the solder with the tip. The solder should melt almost instantaneously. If that’s not the case, be patient and wait a little bit longer.

Tinning and cleaning the soldering tip

The first step is tinning the tip of your soldering iron. To do that, melt a small amount of solder on the tip. This process makes soldering easier and also preserves your soldering tip, protecting it from oxidation.

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Be careful to not inhale the toxic fumes released when you melt solder.

To clean your iron’s tip, wipe it with a wet sponge. It’s a good idea to keep the sponge handy on the iron stand.

Soldering wires to a potentiometer

Soldering the potentiometer leads to three wires is a good way to be initiated into soldering. Some potentiometers aren’t breadboard-friendly, because the leads are hard or even impossible to insert into a breadboard. Having three wires soldered to your potentiometer makes it easy to plug it into a breadboard. Because plenty of electronics projects feature potentiometers, soldering wires to a potentiometer could be quite useful.

Follow these steps to solder the potentiometer leads to the wires:

  1. Touch the soldering iron’s tip to one potentiometer lead.

  2. Let the lead heat up for 2 or 3 seconds.

  3. Touch the solder to the potentiometer lead.

    Your solder should melt right away and solidify shortly after.

    You need just a small amount of solder, and this action should be really quick.

  4. If the solder doesn’t melt, apply heat for a longer period.

During this process, it’s tempting to touch the solder to the iron tip and then spread it around the lead, rather than let it melt through the heat applied to the lead. That process is called a cold solder joint, and the result usually is a bad solder job.

After you’ve soldered the potentiometer lead, you can solder your wire as follows:

  1. Touch the soldering iron to the wire.

  2. Let the wire heat up for 2 or 3 seconds.

  3. Touch the solder to the wire to melt the solder.

    You need only a bit of solder, and it should melt and then solidify very quickly.

When you’ve soldered both surfaces, join them by following these steps:

  1. Connect the wire to the potentiometer lead with the help of a third hand.

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  2. Apply heat to the joined lead and wire with your iron tip.

    The solder you placed previously melts, and the two components stick together.

  3. Add more solder if you think that’s necessary.

  4. Repeat Steps 1–3 for the other two leads of your potentiometer.