Electronics Articles

Cheat Sheet / Updated 09-16-2024

Apple Vision Pro is a mixed-reality headset that fuses augmented reality (where you can see digital information overlaid on top of the real world around you) with virtual reality (realistic imagery that fully envelops your field of vision). You don’t need a mouse and keyboard with Apple Vision Pro — you can control everything with your eyes, voice, and hands in the air. This Cheat Sheet shows you how to use gestures to control Apple Vision Pro, how to capture spatial photos and videos, and more tips for getting the most out of Apple Vision Pro.

Article / Updated 09-11-2024

Android Auto is a new feature available for your Droid smartphone. Because cellphone-related car accidents are on the rise, many major automobile manufacturers have decided to implement a safer way to use your smartphone while driving. Once your Droid is connected to your automobile, the phone’s screen will be mirrored on the display of your car stereo. Credit: Image courtesy of Android.com Android Auto gives you a hands-free option for operating your smartphone while driving. What do you need to use Android Auto? Before you can use the new Android Auto safety feature, you will need to take a couple of things into consideration. Do you have an Android smartphone running OS 5.0 or higher? The Android Auto safety feature is only available on 5.0 (Lollipop) and higher. If your smartphone is running an older Android OS, unfortunately, you will not be able to use Android Auto. Update your device (if applicable) to Android 5.0+. If your device is unable to update to Lollipop and you want this new feature, a new phone purchase may be required. Do you have a data plan through your cellphone provider? Because Android Auto uses data-rich applications such as the voice assistant Google Now (Ok Google) Google Maps, and many third-party music streaming applications, it is necessary for you to have a data plan. An unlimited data plan is the best way to avoid any surprise charges on your wireless bill. Do you have a compatible car or supported aftermarket stereo? Many 2016 automobile models and aftermarket stereos will support Android Auto. If a new car purchase is not in your near future, an aftermarket stereo is a great option. Check the Android Auto page to see if the car or stereo you wish to purchase is supported. What is included with Android Auto? The built in applications supported by Android Auto are listed as follows: Google Maps: The Google Maps app offers directions, road and traffic conditions, as well as travel time. Get directions quickly and accurately. Messages: The Messages application will read incoming text messages. You speak your response into the car stereo/microphone. Android translates your speech into a text and sends it to your recipient. Messages paired with Android Auto allow you to keep your eyes on the road instead of on your Droid. Music: The Music app allows access to the stored music on your smartphone. You can rock out to all your favorite jams directly from the car stereo. Home: Home is a shortcut icon that takes you directly to your Home screen. Here, you can quickly see all of your supported applications and safely make your selection while driving. Phone: The Phone app, paired with Android Auto, allows you to make and receive calls through your car stereo. When a call is coming in, your music or audio pauses and you will hear the ringtone instead. Take or reject the call and the music resumes as soon as you are finished. Applications such as Pandora, Spotify, Google Play Music, and many more are supported. Search the Google Play Store for additional applications. To access other supported applications while your phone is connected to Android Auto, you simply download the applications to your smartphone and coordinating icons will display on your car stereo. If no extra icons are displayed then no supported applications have been downloaded. Keep in mind that Android Auto is not an OS built into your car stereo, but is a feature that allows your phone to display on the screen in your car. Most Android Auto-supported stereos also support Apple CarPlay.

Article / Updated 06-26-2024

Capacitors are among the most useful of all electronic components. And capacitance is the term that refers to the ability of a capacitor to store charge. It's also the measurement used to indicate how much energy a particular capacitor can store. The more capacitance a capacitor has, the more charge it can store. Capacitance is measured in units called farads (abbreviated F). The definition of one farad is deceptively simple. A one-farad capacitor holds a voltage across the plates of exactly one volt when it's charged with exactly one ampere per second of current. Note that in this definition, the "one ampere per second of current" part is really referring to the amount of charge present in the capacitor. There's no rule that says the current has to flow for a full second. It could be one ampere for one second, or two amperes for half a second, or half an ampere for two seconds. Or it could be 100 mA for 10 seconds or 10 mA for 100 seconds. One ampere per second corresponds to the standard unit for measuring electric charge, called the coulomb. So another way of stating the value of one farad is to say that it's the amount of capacitance that can store one coulomb with a voltage of one volt across the plates. It turns out that one farad is a huge amount of capacitance, simply because one coulomb is a very large amount of charge. To put it into perspective, the total charge contained in an average lightning bolt is about five coulombs, and you need only five, one-farad capacitors to store the charge contained in a lightning strike. (Some lightning strikes are much more powerful, as much as 350 coulombs.) It's a given that Doc Brown's flux capacitor was in the farad range because Doc charged it with a lightning strike. But the capacitors used in electronics are charged from much more modest sources. Much more modest. In fact, the largest capacitors you're likely to use have capacitance that is measured in millionths of a farad, called microfarads and abbreviated μF. And the smaller ones are measured in millionths of a microfarad, also called a picofarad and abbreviated pF. Here are a few other things you should know about capacitor measurements: Like resistors, capacitors aren't manufactured to perfection. Instead, most capacitors have a margin of error, also called tolerance. In some cases, the margin of error may be as much as 80%. Fortunately, that degree of impression rarely has a noticeable effect on most circuits. The μ in μF isn't an italic letter u; it's the Greek letter mu, which is a common abbreviation for micro. It's common to represent values of 1,000 pF or more in μF rather than pF. For example, 1,000 pF is written as 0.001 μF, and 22,000 pF is written as 0.022 μF.

Cheat Sheet / Updated 03-26-2024

Can't wait to use your new iPad? The Apple iPad neatly combines an audio and video iPod, an e-book reader, a powerful internet communications device, a handheld gaming device, and a platform for millions of apps. After you open the box and see what’s inside, you need to know about its buttons and controls and how to use the multitouch display. And if you ever catch your iPad behaving badly, check out the five tips for setting your iPad back on track.

Cheat Sheet / Updated 11-01-2023

Your iPhone can be so much more than a communication tool to talk into. Aside from making calls and creating your contacts, you should make yourself familiar with the many options available on the iPhone touchscreen. You'll also want to be able to handle troubleshooting when your Apple device acts strangely or stops working. When you need a bit of levity, check out our 10 ways to have fun with Siri. And finally, if you have an iPhone with Face ID, you’ll discover how to put your iPhone into recovery mode.

Cheat Sheet / Updated 10-31-2023

This cheat sheet gives you a rundown of some of the most useful features and apps so you can find what you need to customize your iPhone’s behavior. See how to get the most out of Siri (your iPhone’s virtual assistant), review some favorite apps for news and weather, and discover several of the most popular apps for multimedia.

Article / Updated 09-13-2023

Before you can fire up your Raspberry Pi and start building your own electronics projects, you need to do some basic setup work. Start by setting up the hardware. You'll need the following to set up your Pi so that you can program it for your projects: A Raspberry Pi 2 or 3. A suitable power supply: The Raspberry Pi requires a 5 V power supply connected via a micro-USB connection on the card. The Pi itself will draw about 800 mA, so be sure to use a power supply that can handle at least that much current draw. A monitor: You don't need a large monitor, but go for at least 17 inches. An HDMI cable: If your monitor has an HDMI connection, you'll need a cable with HDMI connectors on both ends. If your monitor has some other type of connection, such as DVI or VGA, you'll need an adapter to connect your monitor to the Pi's HDMI connector. A USB keyboard: Any keyboard with a USB connector will do. A USB mouse: Any mouse with a USB connector will do. A microSD card with NOOBS: The Raspberry Pi uses a microSD card instead of a disk drive. Ideally, you should purchase a microSD card that already has a special program called NOOBS installed on it. (NOOBS stands for New Out Of the Box Software.) This program will allow you to install an operating system so that your Pi can run. If you prefer, you can format your own microSD card for your Pi. You can do that by downloading NOOBS from Raspberry Pi — Teach, Learn, and Make with Raspberry Pi on your computer and then copying the NOOBS software to the microSD card. A network connection: A network connection is essential to download several of the support packages you'll need for your projects. You can connect your Pi to a network in one of two ways: If you have a Raspberry Pi 3, you can use the built-in Wi-Fi to connect to a wireless network. You can use a standard Ethernet cable to plug a Raspberry Pi 2 or 3 into a wired network, provided you have a nearby router or switch with an available network port. That's all you need to get started. Plug the monitor, mouse, and keyboard into your Pi's HDMI and USB ports, insert the microSD card into the microSD slot, and then plug in the power connector. Your Pi will start right up.

Article / Updated 09-11-2023

All of electronics can be divided into two broad categories: analog and digital. One of the most common examples of the difference between analog and digital devices is a clock. On the analog clock, the time is represented by hands that spin around a dial and point to a location on the dial that represents the approximate time. On a digital clock, a numeric display indicates the exact time. Analog refers to circuits in which quantities such as voltage or current vary at a continuous rate. When you turn the dial of a potentiometer, for example, you change the resistance by a continuously varying rate. The resistance of the potentiometer can be any value between the minimum and maximum allowed by the pot. If you create a voltage divider by placing a fixed resistor in series with a potentiometer, the voltage at the point between the fixed resistor and the potentiometer increases or decreases smoothly as you turn the knob on the potentiometer. In digital electronics, quantities are counted rather than measured. There’s an important distinction between counting and measuring. When you count something, you get an exact result. When you measure something, you get an approximate result. Consider a cake recipe that calls for 2 cups of flour, 1 cup of milk, and 2 eggs. To get 2 cups of flour, you scoop some flour into a 1-cup measuring cup, pour the flour into the bowl, and then do it again. To get a cup of milk, you pour milk into a liquid measuring cup until the top of the milk lines up with the 1-cup line printed on the measuring cup and then pour the milk into the mixing bowl. To get 2 eggs, you count out 2 eggs, crack them open, and add them to the mixing bowl. The measurements for flour and milk in this recipe are approximate. A teaspoon too much or too little won’t affect the outcome. But the eggs are precisely counted: exactly 2. Not 3, not 1, not 11/2, but 2. You can’t have a teaspoon too many or too few eggs. There will be exactly 2 eggs, because you count them. So which is more accurate — analog or digital? In one sense, digital circuits are more accurate because they count with complete precision. You can precisely count the number of jelly beans in a jar, for example. But if you weigh the jar by putting it on an analog scale, your reading may be a bit imprecise because you can’t always judge the exact position of the needle. Say that the needle on the scale is about halfway between 4 pounds and 5 pounds. Does the jar weigh 4.5 pounds or 4.6 pounds? You can’t tell for sure, so you settle for approximately 4.5 pounds. On the other hand, digital circuits are inherently limited in their precision because they must count in fixed units. Most digital thermometers, for example, have only one digit to the right of the decimal point. Thus, they can indicate a temperature of 98.6 or 98.7 but can’t indicate 98.65. Here are a few other thoughts to ponder concerning the differences between digital and analog systems: Saying that a system is digital isn’t the same as saying that it’s binary. Binary is a particular type of digital system in which the counting is all done with the binary number system. Nearly all digital systems are also binary systems, but the two words aren’t interchangeable. Many systems are a combination of binary and analog systems. In a system that combines binary and analog values, special circuitry is required to convert from analog to digital, or vice versa. An input voltage (analog) might be converted to a sequence of pulses, one for each volt; then the pulses can be counted to determine the voltage.

Video / Updated 09-08-2023

Alexa works as a smart-home controller, so it can recognize and work with multiple devices from multiple manufacturers. An Alexa device such as an Echo or Echo Spot is an example of such a controller. Devices Alexa can control (like thermostats, speakers, TVs, and so on) just have to be compatible. You must make sure you get smart-home devices that are compatible with your controller, so be sure to buy items that are Alexa compatible. Smart-home devices are all the rage. Using apps on smart phones or simple voice commands from Alexa, you can control light bulbs, thermostats, garage door openers, security cameras, and so much more. To get your Alexa device to connect to and operate smart-home devices, you'll be using either your home’s Wi-Fi network or a direct Bluetooth connection. In most cases, the connection procedure involves two steps: For a Wi-Fi connection, use the manufacturer’s app to give Alexa permission to connect to the device. Enable the manufacturer’s device skill to update Alexa with the voice commands needed to operate the device. How to set up a smart home with Alexa If your smart-home device is Wi-Fi-friendly, go to your mobile device app store and install the manufacturer’s app. Then follow these steps to get your Wi-Fi smart-home device set up in the app: 1. Plug in and, if required, turn on the smart-home device. 2. Open the smart-home device manufacturer’s app. 3. Initiate the procedure for setting up a new device. Look for a command named Add or Add [manufacturer] Device (where manufacturer is the name of the company), or just a big plus sign (+). The setup routine will tell the device to broadcast its Wi-Fi network. 4. Open your mobile device’s Wi-Fi settings and look for the device’s Wi-Fi network. 5. Tap the device network to connect to it. 6. When the connection is complete, return to the device app. The app automatically detects the new network and uses the connection to set up the device. This usually involves giving the device a name. You’ll often have to set up an account with the manufacturer, as well. 7. The app will usually ask for your Wi-Fi credentials, which enables the device to connect to and operate over your network. Having the device on your network is also how Alexa discovers and operates the device, so this step is important. 8. If you see a notice asking whether you want to upgrade the smart-home device firmware, by all means tap Yes or Allow or Update or whatever button answers in the affirmative. With your smart-home device installed, you can view it and rename it if you so desire in the Alexa app. Just tap the Devices icon to open the Devices screen, and from there, you can change the settings for your device. Discover Smart-Home Devices Using an Alexa skill If you’re not using an Alexa device that includes a smart-home hub (such as the Echo Plus and second-generation Echo Show), then you usually need to upgrade Alexa to work with your smart-home device. You upgrade Alexa by enabling the device manufacturer’s Alexa skill. This not only lets Alexa discover the device but also upgrades Alexa with the voice commands that enable you operate the device. 1. Install the manufacturer’s app and use it to get your smart-home device on your Wi-Fi network. 2. In the Alexa app, tap Devices. 3. Tap the Add button (+) that appears in the top-right corner. 4. Tap Add Device. The Alexa app displays icons for some popular brands and some device categories. 5. Tap the category that fits your device, and then tap the manufacturer. The Alexa app prompts you to perform the duties I outline in Step 1. You’ve done all that, so proceed. 6. Tap Continue. The Alexa app opens the information page for the manufacturer’s Alexa skill. 7. Tap Enable. At this point, what happens next depends on the skill, but you’ll usually have to perform one or both of the following: Use the smart-home device app to give Alexa permission to access the device. Link Alexa to the user account associated with the smart-home device. 8. When you’re done, tap Close (X) to return to the skill page. 9. Tap Discover Devices. The Alexa app uses the manufacturer’s Alexa skill to search for available devices. 10. Tap Done. With a manufacturer’s Alexa skill enabled, you can discover new devices by following steps 1 through 5 and then tapping Discover Devices, or you can ask Alexa to run the following voice command: “Alexa, discover my devices.” Control Smart-Home Devices with Alexa Devices Alexa can control are any Alexa-compatible plugs, lights, thermostats, garage door openers, security devices, speaker, TVs, and so on. There are actually three methods you can use to control a smart-home device: Voice commands: This is how you’ll operate most of your smart-home devices, and the rest of this section takes you through the most common voice commands for a selection of smart-home devices. Alexa app: If you have your Alexa device microphone turned off, you can still use the Alexa app to control your smart-home devices. Tap Devices, tap the device type (or All Devices), and then tap the device you want to mess with. The screen that appears contains the controls you can use. Alexa device with a screen: Swipe down from the top of the screen to open the status bar, and then tap the icon for the device type (such as a bulb icon for your smart lights, plugs, and switches). Note, too, that after you issue a smart-home device-related command to an Alexa device with a screen, you see some device controls on the screen for a few seconds. Turn smart plugs on and off with Alexa A smart plug is an electrical outlet that you can control with voice commands. The smart outlet plugs into a regular electrical outlet for power and then you plug a non-smart device — such as a lamp or coffeemaker — into the smart outlet. Voilà! You now have voice control over the dumb device. Note, however, that “control” here just means turning the device on and off using the following voice commands: “Alexa, turn [device name] on.” “Alexa, turn [device name] off.” Replace device name with the name you gave to the smart plug using either the manufacturer’s app or the Alexa app. Work with smart lights and Alexa Another easy and relatively inexpensive way to get your smart-home feet wet is with a smart lightbulb or two. You can buy a smart bulb for less than $20, and installing it is as easy as changing any regular lightbulb. You can also get smart bulbs that change brightness without a separate dimmer switch and that can display different colors. Here are the voice commands to use to turn a smart lightbulb or light switch on or off: “Alexa, turn [device name] on.” “Alexa, turn [device name] off.” For dimmable smart lights (or smart dimmer switches), use any of the following voice commands: “Alexa, brighten [device name].” “Alexa, dim [device name].” “Alexa, set [device name] brightness to [number] percent.” For smart lights that support different colors, use these voice commands: “Alexa, set [device name] to warm white.” “Alexa, set [device name] to cool white.” “Alexa, set [device name] to [color].” (For example, “Alexa, set Chill Room to blue.”) Control smart thermostats with Alexa A smart thermostat gives you voice control over not only the thermostat mode — for example, switching between heating and cooling — but also the temperature setting. You can also interrogate a smart thermostat to learn the current temperature setting. After you’ve installed a smart thermostat, you can control it using the following voice commands: “Alexa, set [device name] to cool.” “Alexa, set [device name] to heat.” “Alexa, set [device name] to auto.” “Alexa, set [device name] to off.” “Alexa, set [device name] to [number] degrees.” “Alexa, increase [device name] by [number] degrees.” “Alexa, decrease [device name] by [number] degrees.” “Alexa, what is [device name]’s temperature?” “Alexa, what is [device name] set to?” Keep an eye on things with Alexa and smart cameras Smart cameras come in both outdoor versions and indoor versions. Outdoor cameras are usually called security cameras or surveillance cameras. You can also get a smart doorbell that has a built-in camera that activates whenever someone rings the bell. If you have an Alexa device with a screen, you can show the smart camera’s feed right on your screen by saying the following voice command: “Alexa, show [device name].” To turn off the camera feed, issue the following voice command: “Alexa, hide [device name].” Other Types of Smart-Home Devices That Work with Alexa Here’s a quick summary (in no particular order) of what’s out there that’s Alexa-friendly: Smart speakers: Echo isn’t the only smart speaker game in town. Big-time audio companies such as Bose, Denon, and Sonos have their own smart speakers that have Alexa built in. Smart locks: These are door locks that you can control with your voice. Smart sprinklers: You can control and schedule garden and lawn watering with a smart sprinkler system. Smart TVs: This is a television or remote that you can control by voice. Smart appliances: These are kitchen appliances that you can operate with voice commands. Amazon’s new Alexa-friendly microwave is the latest addition to this category. Smart vacuums: Why push a vacuum yourself when you can have a robot vacuum that you control via voice?

Article / Updated 08-14-2023

Over the last couple of years, Apple added a handy Dock feature for Apple Watch wearers. You activate Apple Watch Dock by pressing in on the side button. Quite simply, Dock lets you quickly open your favorite apps or move from one app to another. Here’s how to get going: Choose which apps you want to appear in Dock. You can select up to ten of your favorites, in fact. To choose what you want, simply: Open the Apple Watch app on iPhone. Tap My Watch and then choose Dock. Tap Edit and then add or remove apps to choose your favorites. To rearrange apps, touch and hold next to an app, then drag up or down. Save your changes by tapping Done. Press the side button to activate Dock. Swipe up or down. Alternatively, you can turn the Digital Crown. This will cycle through the last apps you opened or your favorite apps. Tap to open an app. If you scroll all the way down to the bottom of the screen, you can tap All Apps to go to the Home screen. Close Dock by pressing the side button again. How to launch Dock and more Here’s how to launch Dock, screen between apps, launch one, and change what you see there. Press the side button. This activates Dock on Apple Watch. Swipe up or down with your fingertip or turn the Digital Crown. This cycles through the last apps you opened or your favorite apps (see the next section on how to customize this). The figure shows an example of what it looks like to cycle through some apps. To close an open app in from Dock, swipe to the right and press the big red “X.” Tap the name of the app to open it full-screen. If you scroll all the way down to the bottom of the screen, you can tap All Apps to go to the Home screen. To close Dock, press the side button again. How to customize Dock To choose which apps appear in Dock — up to ten of your favorites — follow these steps: Grab your iPhone and open the Apple Watch app. Tap My Watch, then Dock. Here you can choose your favorite apps. Tap Edit and then add or remove apps. To remove apps, tap the red –, then tap Remove. To add apps, tap the green +. To rearrange apps, touch and hold next to an app, then drag up or down. Tap Done. This saves your changes.