Ready to build on a newfound knowledge of electronics? Want to expand your horizons and create programmable electronics projects? The following list provides you with a list of ideas for enhancing your electronics experience.
Surfing for circuits
Thousands of project ideas are available on the Internet. Use your favorite search engine to find projects in topics or specific parts that interest you. For instance, search for simple audio circuits or 555 timer circuits to get loads of ideas — some with complete explanations, schematics, and photographs of a breadboarded circuit. Or choose an idea for a circuit and see if one is out there already. A search for door alarm circuit, for example, turns up many simple circuit ideas and even YouTube videos.
Getting a jumpstart with hobby kits
If you want to make some cool things happen but don't want to start from scratch, you can purchase one or more electronics hobby kits. These kits include everything you need to build a functional circuit: all the electronic components, wire, circuit board, and detailed instructions for putting the circuit together. Some even include an explanation of how the circuit works.
Simulating circuit operation
If you have a complicated circuit design or just want to understand more about how a particular circuit will behave when powered up, you can use a circuit simulator. This software program uses computer-based models of circuit components to predict the behavior of real circuits. You tell it what components and power supplies you're using and how they should be wired, and the software tells you whatever you want to know about the operation of the circuit: the current through any component, voltage drops across components, circuit response across various frequencies, and so forth.
Scoping out signals
An oscilloscope is a piece of test equipment that displays how a voltage varies with time as a trace across a cathode-ray tube (CRT) or other display that contains a calibrated grid. You use a scope to visualize what is happening to rapidly varying voltages in your circuits. If you're interested in building audio amplifiers and other circuits that have time-varying signals, such as sound, an oscilloscope can come in handy and help you understand circuit operation and pinpoint errors. A good scope costs a few hundred dollars but you may be able to find some great deals on eBay or Craigslist.
Counting up those megahertz
You can use a frequency counter (or frequency meter) to help you determine whether your AC circuit is operating properly. By touching the leads of this test device to a signal point in a circuit, you can measure the frequency of that signal. For example, suppose you create an infrared transmitter and the light from that transmitter is supposed to pulse at 40,000 cycles per second (also known as 40 kHz). If you connect a frequency counter to the output of the circuit, you can verify that the circuit is indeed producing pulses at 40 kHz — not 32 kHz, 110 kHz, or some other Hz.
Generating a variety of signals
To test a circuit's operation, it often helps to apply a known signal input to the circuit, and observe how the circuit behaves. You can use a function generator to create repeating-signal AC waveforms in a variety of shapes and sizes — and apply the generated waveform to the input of the circuit you're testing. Most function generators develop three kinds of waveforms: sine, triangle, and square. You can adjust the frequency of the waveforms from a low of between 0.2 Hz and 1 Hz to a high of between 2 MHz and 20 MHz. Some function generators come with a built-in frequency counter so you can accurately time the waveforms you generate. You can also use a stand-alone frequency counter to fine-tune the output of your function generator.
Exploring basic computer architectures
Circuits such as the half-adder form the foundation of computer architectures. By connecting multiple logic gates in just the right way, you can create circuits that compute, store, and control information (series of 1s and 0s organized into groups of 8 called bytes). Start your journey into the fascinating field of computer architecture by building digital logic circuits that use LEDs as output indicators. (Check out this detailed description of how to build a 4-bit binary full adder.)
Microcontrolling your environment
A microcontroller is a tiny computer on a chip. You create a program on your computer, and download the program onto the chip. Then when you power up the chip, it follows the instructions in your program. The BASIC Stamp and PICAXE microcontrollers are inexpensive alternatives that use the easy-to-learn BASIC programming language. However, the beginner-friendly Arduino microcontroller system, which uses a C-like programming language, has exploded in popularity in recent years due to its simplified integrated development environment (IDE), versatility, affordability, and enormous online user community.
Getting a taste of Raspberry Pi
The Raspberry Pi is a series of single-board computers that you connect to your TV or monitor and a standard keyboard. The original Pi runs the Linux operating system, but the second generation Pi runs both Linux and a version of Windows 10. You program the Pi using Python or any one of a number of IDEs. Although it's not as beginner-friendly as Arduino, the Raspberry Pi is as inexpensive (roughly $35) and has a large online user community.
Try, fry, and try again
Perhaps the best way to expand your knowledge of electronics is to develop your own ideas, design some circuits, build and test them, and then go back and tweak your design. Sometimes the only way to find out what the limitations of various parts or designs are is to fry a few LEDs, toast a couple of ICs, or stay up all night probing the depths of a nonworking circuit until you figure out what's wrong with it. To quote a popular science teacher, Valerie Frizzle, "Take chances, make mistakes, get messy!" (But, please, take safety precautions no matter what else you do!)