2-1 has all these things covered.
Figure 2-1: A good working environment and some basic tools.
✔ A solid workbench or desk
✔ A comfortable chair
✔ Dry air and good ventilation (especially for evacuating soldering fumes)
✔ Plenty of power outlets, ideally at desk height
✔ Enough room for the screen, keyboard, and mouse, and some extra workbench space for assembly and fabrication
✔ A nearby network connection or Wi-Fi router
✔ Shelving and storage for projects you’re working on
✔ Small boxes and drawers for organizing parts and tools
The environment needs to be comfortable to work in for a long stretch. If it’s too cold or too hot, too noisy, or filled with distractions, it’ll take you longer to complete the work. Make yourself a sort of hideaway where you can stay focused.
Your Raspberry Pi is a fine computer in its own right, but an extra computer is sometimes useful during the project-building process, so it’s good to have room for a desktop or laptop computer on the workbench. Plus, you’ll want to be able to hunt for references online, look up datasheets, and post questions to forums, so a reliable Internet connection is vital.
Keeping an eye on safety
A few of the projects in this book deal with low-voltage electronics. Safety is always a factor when working with electrical circuits. None of these projects works with wall power, but you should always treat electronic projects as if they could have potentially dangerous voltages. If children may roam around your work area, take special precautions to keep them away. Little kids love pulling on cords and cables and could easily drag everything off your desk with one quick tug. A hot soldering iron left unattended could cause severe burns, besides being a fire hazard.
It’s probably best to keep food and drink separate from your workbench. Empty pizza boxes or soda cans may hide critical parts, and you can waste time hunting for things. Accidentally spilled drinks don’t do good things for live circuits.
Assembling Your Tools
You need some basic tools to build several of the projects in this book. The tools basically fall into two categories: electronics tools and physical building and fabrication tools. You can get most or all of these components from electronics retailers such as Radio Shack (in the United States) or Maplin (in the UK). Specialty electronics suppliers on the Internet also stock them and are often cheaper, so hunt around at places like Farnell (www.farnell.com), Newark (www.newark.com), Rapid Electronics (www.rapidonline.com), and RS (www.rs-components.com). Sometimes you can find good deals on Amazon (www.amazon.com) and eBay (www.ebay.com), too.
Electronics tools
Here are the basic electronics tools you’ll want on your shopping list:
✔ A multimeter: A multimeter is an essential tool for most electronic projects. You use it to perform basic tests to make sure that you have good connections in your electrical circuits. With a multimeter, you can measure the characteristics of an electrical circuit and troubleshoot why something may not be working. A multimeter is also handy for testing and measuring individual electronic components. You should have one on hand for testing and troubleshooting your projects. (See the following section, “Selecting a multimeter,” for more information.)
✔ A breadboard and jumper wires: Some of the projects in this book involve wiring up electrical components, LEDs, sensors, or actuators to your Raspberry Pi. This can be as simple as one or two wires, but some of the projects have many connections. A breadboard is a simple tool to help you easily make all these electrical connections. You need jumper wires to make connections when you’re using a breadboard. Wires come in solid core and stranded versions (which contain many fine wires). You need solid core jumper wires for working with breadboards.
✔ A soldering iron: A breadboard is ideal for temporary connections and prototyping, but for some connections you’ll want something more permanent. This is where a soldering iron comes in. You use a soldering iron to make strong, permanent connections between electronic components. If you want to mount buttons onto an enclosure for your project, you’ll probably want to solder wires to the buttons and connect these to your Raspberry Pi. You can even build part of your circuit on a breadboard and use soldered connections for switches or sensors that are located some distance away. (See the upcoming section, “Selecting a soldering iron and accessories,” for more information on what to look for.)
✔ A power supply: None of the projects in this book requires a desktop power supply, so this is optional. But for general electronics experimenting, you’ll probably want to have a power supply on hand.
Selecting a multimeter
A multimeter is an essential tool for testing, measuring, and diagnosing problems in electronic circuits. You use a multimeter to measure several basic attributes of your circuit, including:
✔ Continuity: Whether there is a good connection between two points
✔ Voltage: The measure of potential electromotive force in a circuit
✔ Current: The measure of the continuous, uniform flow of electrons through an unbroken pathway in an electrical circuit
✔ Resistance: Opposition to the flow of current within a circuit
With a multimeter, you can also measure the voltage provided by batteries and power supplies, and the characteristics of discrete electronic components, such as resistors, capacitors, diodes, and transistors.
✔ Continuity with audio signal: Checking continuity – making sure that the things you think are connected really are connected – is the task you’ll use your multimeter for most often. You touch the two probes to part of a circuit to see if they’re connected, and the multimeter screen displays a confirmation. With cheap multimeters, you need to hold the probes in place while looking at the screen, which can be annoying if the probes slip off. It’s a pain to check continuity by holding leads on a circuit while you’re also looking at the display. It’s much easier to just poke around and listen for an audio signal. Meters with audio output will beep when you test for good continuity so you don’t have to take your attention
