Читать книгу Raspberry Pi Projects For Dummies - Evans Jonathan - Страница 19

When you’ve assembled all the tools and set up your workspace, you’ll probably be eager to dive right in! But before you do, take a few minutes to read the information in this section so you don’t hurt yourself or those around you.

Working with electricity

In working with electronics, safety is critical. You should take basic precautions to protect yourself. None of the projects in this book involves connecting directly to the wall power, but you should use precautions anyway and develop good safety habits. Even though you may only be working with low DC voltages, it’s a good idea to follow some basic safety rules when working with all electronic projects:

✔ Don’t touch metal contacts or leads in a live circuit.

✔ Don’t alter a live circuit. Always disconnect power before removing or adding components to your Raspberry Pi or breadboard.

✔ Always test with one hand tied behind you back. Well, at least one hand not on the work piece. If enough stray current flows between both your hands, and across your heart, it can cause arrhythmia. That’s not likely at the low DC voltages we’re working with here, but it’s best to be safe and get into the habit.

✔ Sounds crazy, but don’t work barefoot. Maximize the resistance between you and the floor by wearing good, rubber-soled shoes. A puddle of water is a great conductor, and you don’t want to be in one, if something goes wrong.

✔ Wear an antistatic wrist strap. Your Raspberry Pi is a tough little computer, and if it’s in an enclosure it should be well protected. However, it and other components are sensitive to wayward voltages, including static electricity. Several thousand volts of static electricity can build up on you, and you may not even know it, especially on carpeted floors. If it does and you touch your hardware, you can fry it in an instant. An inexpensive antistatic wrist strap will guard against unexpected sparks by connecting you at all times to ground, which diverts any electrical charge from building up on your body.

✔ When fabricating or soldering, wear light, comfortable safety glasses. Wire offcuts can fly around the room when they’re clipped, and hot solder can sometimes spit and splutter. You don’t want any molten metal heading for your eyes.

Laying the foundation for your electronics work

To quickly and easily connect your project circuits, start out by using a breadboard. All the projects involving electronic circuits in this book can be built on a breadboard. After testing on a breadboard, you can either put your Raspberry Pi and your breadboard inside an enclosure or build your circuit permanently on a stripboard or perfboard, which requires a bit of soldering.