Arduino Foundations Flashcards
One of the world’s first computers
the Antikythera mechanism used simple arithmetic and geometry to calculate astronomical positions created by the Ancient Greeks
The difference machine
A complicated analog calculator envisioned and partially build by Charles Babbage in 1833, later completed by lovelace.
Enigma and Bombe devices
During World War II, Germans used the Enigma device to encrypt important military messages into a code that was unbreakable – or so they thought. The British used a computing device called the Bombe (1939) to decrypt these secret messages. The insights of Alan Turing were essential. Some believe Turing helped end the war and saved millions of lives. He certainly revolutionized computing. Though tragically he received no credit in his lifetime.
The Eniac
ENIAC (1945), the first true general computer, was funded by the United States to calculate the paths of missiles and help create the hydrogen bomb. ENIAC was the size of a room. It used mechanical and electrical components. While working with ENIAC, mathematician John von Neumann developed ideas about computing that have shaped computer design ever since; memory storage, information input and output, and binary code all have a debt to von Neumann.
First Microcontroller
Gary Boone, an engineer at the company Texas Instruments, is credited with the first single-chip microcontroller in 1971. Boone also played a part in the development of early microprocessors, a similar innovation.
Capacitor
Capacitor – A component that stores and releases electrical energy in a circuit. When the circuit’s voltage is higher than what is stored in the capacitor, it allows current to flow in, giving the capacitor a charge. When the circuit’s voltage is lower, the stored charge is released. Capacitors are often placed across power and ground close to a sensor or motor to help smooth changes in voltage. Capacitors are measured in farads. One farad is a lot of capacitance, so most capacitors are in the microfarad (0.000001 farads) or even picofarad (0.000000000001 farads) range.
Anode
Anode – The electrode or wire through which current enters a device, such as an LED, where current can flow only in one direction
Breadboard
Breadboard – A device used for prototyping electronic circuits that allows for easy connection of electronic components
Cathode
Cathode – The electrode or wire through which current exits a device, such as an LED, where current can flow only in one direction
Circuit
Circuit – A conductive path that electric current can flow through
Conductor
Conductor – A material that allows electrons to easily pass through it
Conductance
Conductance – A measure of how well a material allows electrons or electrical current to flow through it; measured in siemens
Current
Current – A measure of the number of electrons (or amount of charge) passing through a point in a circuit in a specific time; measured in amperes (amps)
Electron
Electron – A part of an atom that is negatively charged and can be passed from atom to atom, creating a flow of electricity
Insulator
Insulator – A material that resists the flow of electrons
Ohms law
Ohm’s law – A scientific law that states that voltage is directly proportional to current V = I • R
Prototype
Prototype – An initial model of a device that can be used for testing and modification from which the final product is developed
Resistance
Resistance – A measure of the opposition to the flow of electrons through a material; measured in ohms
Resistor
Resistor – An electronic component that reduces the current in a circuit
Voltage
Voltage – A measure of the difference in electrical energy between two points; measured in volts
Transistors designed in what year?
1947
Significance of the first transistor
Transistors began the modern electronics revolution. For the first time, we could control the movement of electrons.
They can be used to amplify signals, to build microchips, or as electronic switches. Transistors are used in computers, radios, televisions, phones, digital cameras, robots, and any other electronic device you could imagine.
How does a resistor work
Reduces the flow of electrons by converting a certain amount of electricity to heat.
electrical unit prefixes
Mega - Million Kilo - thousand milli - thousandth micro - millionth nano - billionth pico - trillionth
Color codes of Resistors
Black = 0 Brown = 1 Red = 2 Only = 3 Young = 4 Green = 5 Blue = 6 Purple = 7 Silver = 8 White = 9
Tollerance Bands of Resistor
Brown = 1% Red = 2% Gold = 3% Silver = 5%
Non polarized component
A resistor is considered a non-polarized component. That means it doesn’t matter which way the resistor faces in the circuit.
Load
anything in a circuit that requires electricity to work
Difference between conventional flow and electron flow
Electrons flow from negative to positive. But before electricity was fully understood, scientists such as Ben Franklin thought the positive charges moved through the circuit to create current. This is known as the conventional approach to current flow. In this approach, current flows from positive to negative.
Current flows in DC circuits
In circuits with DC power sources, the current flows in one direction – positive (power) to negative (ground).
Current flows in AC Circuits
With AC sources, the direction of current flow changes back and forth. As the current changes direction, the voltage in the circuit reverses, forcing the current to flow the other way. Most homes and buildings are powered by AC circuits. For example, the electricity coming from a wall outlet in an American home changes direction 60 times in one second.
Parrallel circuit
Parallel circuit – A circuit where components are wired in such a way that there are multiple paths for electricity to flow through.
Schematic diagram
Schematic diagram – A representation of a circuit that uses graphical symbols to represent each component.
Series circuit
Series circuit – A circuit where components are wired one after the other, forming a single path for current to flow through.
Wiring diagram
Wiring diagram – a representation of a circuit that uses pictures to show how components in a circuit are connected.
What is the forward voltage of a led
The minimum voltage required for the led to activate
Actuator
A device controlled by a microcontroller to perform a certain task.
Capacitance
The measure of a component’s ability to store electric charge
Capacitance is a measure of how much charge a capacitor can collect and store. It is measured in units called farads, named after Michael Faraday. (You can read about Michael Faraday in this lesson’s Invention Spotlight.) Generally, the larger a capacitor’s physical size, the more capacitance it has. For example, a one-farad capacitor would be pretty large – perhaps the size of a two-liter bottle of soda.
Capacitor
An electrical component that stores an electric charge.
Class
A template that describes an object; it includes variables that hold properties of an object and methods that describe what the object can do.
Constant
In programming, a value that never changes as the program runs.
Dielectric
The material in a capacitor that insulates one plate from the other
Inside a capacitor, the terminals are connected to conductive metal plates that are separated by an insulator. The insulator that separates the plates is called a dielectric and can be made from ceramic, porcelain, glass, and even air. The dielectric material is what gives capacitors a wide range of types and uses.
Sensor
A device designed to indicate or measure something and converts that measurement to an electrical signal that a microcontroller can read; sensors provide input to the Arduino UNO R3 board.
Servo
A type of motor that includes its own driver and is used for precise positioning in either direction.
Difference between polarized and non polarized capacitors
Capacitors have two terminals. Some capacitors, like the ones in your kit, are polarized. They have an anode and a cathode. With polarized capacitors, electrons flow in only one direction. Therefore, polarized capacitors are generally used in DC applications where current flows in one direction. Non-polarized capacitors allow electrons to flow in either direction. This makes them great for AC applications where current alternates directions. However, they can also be used in DC circuits
Difference between battery and capacitors
Capacitors can discharge all their stored electrons very quickly whereas batteries discharge slowly. This makes the potential uses for batteries and capacitors much different. Batteries are good at supplying current over time, while capacitors are good at managing quick changes in current.
will a capacitor discharge slower or faster if you replace a 10 Kohm resistor with a 220 ohm one?
The capacitor will discharge much quicker. The lower the resistance in the circuit, the more current can flow through the circuit.
A capacitor’s time constant
A capacitor’s time constant is equal to the resistance of the circuit in ohms times the capacitance of the capacitor in farads.
Tc = R • C
Capacitors discharge exponentially, A capacitor’s time constant (Tc) is the time it takes a capacitor to discharge to 37% of its initial voltage. After two time constants, a capacitor will discharge to 13.7% of its original voltage (37% of 37 is 13.7%)
In all truth, a capacitor will never fully discharge. A multimeter might say a capacitor has zero voltage, but that’s just because the voltage is too small to be read by the multimeter. It is generally accepted that a capacitor has fully discharged after five time constants. In other words, a capacitor’s discharge time equals 5Tc
Electric motors
Inside an electric motor is a magnet. Magnets have two poles – a north pole and a south pole. Also inside a motor are several coils of wire. When electricity passes through the wire, it creates an electromagnet that also has a north and a south pole. As you probably already know, like poles repel and opposite poles attract. This causes the motor to rotate as it tries to align itself with the magnetic field. As the motor turns, the current flowing through the coils changes direction. This flips the poles of the electromagnet and, since like poles repel and opposite attract, the motor continues to turn. The motor spins because this process repeats over and over. Changing the voltage to the coil changes the strength of the electromagnet and affects how fast the motor spins.
Frequency
The number of vibrations, cycles, or waves that pass a certain point in one second
Hertz
A unit of frequency that is a measure of cycles per second
Medium
Any substance through which waves transfer energy from one place to another
Octave
A series of eight notes where the last note has twice the frequency of the first note
Period
The time it takes for an object or wave to complete one vibration or one cycle
Piezo buzzer
An electronic component that has a vibrating membrane that creates sound
Most piezo membranes are made of a ceramic disk placed on top of a metal disk. Rather than being struck by a drumstick, a piezo membrane vibrates due to electric current. When current passes through the membrane, it deforms. When the current stops, the membrane goes back to its original shape. When current is turned on and off very quickly, the membrane vibrates back and forth, creating sound waves that you can hear.
By changing how fast the current is turned on and off, you can control the speed of the vibration. Faster vibrations create higher pitches while slower vibrations create lower pitches.
Resistor ladder
An electrical circuit composed of resistors that output different voltages that can be interpreted as analog signals
A resistor ladder is kind of like a potentiometer except that instead of having a nearly infinite amount of voltage possibilities, there are specific voltage steps created by different resistors
calculate frequency
Period = Rate / 1000
Frequency = 1/Period
calculate frequency
Period = Rate / 1000
Frequency = 1/Period
ASCII code
A code that assigns a number that can be represented as a byte of data to all upper and lowercase letters of the English alphabet, the numbers 0 through 9, and some special characters.
Buffer
A data storage location that holds data for a short time as it is moved from one place to another.
Called function
Lines of code separate from the main program that perform a certain task; called functions can be run at any time within the main program whenever that task needs to be completed
Electromagnetic spectrum
The range of all the different types of electromagnetic waves (including light) that are distinguished by their wavelengths.
Electromagnetic wave
A wave that transmits energy by changing electric and magnetic fields; electromagnetic waves do not need a medium to travel through and have a wide range of wavelengths.
Fiber optics
The use of light to transmit information through thin fibers or cables made from glass or plastic.
Phototransistor
An electronic component that converts light energy into electrical energy.
In a way, it is the opposite of an LED. An LED converts electrical energy into light energy.
If this process is reversed, the LED becomes a photodiode and can be used to detect light.
As light strikes the photodiode, light energy is converted into electrical energy, and an electric current is produced
Transverse wave
A wave that oscillates or vibrates at right angles to the direction it moves.
Wavelength
The distance between two consecutive wave crests; wavelength determines the characteristics of an electromagnetic wave.
Differences between sound waves and electromagnetic waves
electromagnetic waves are transverse, while sound waves are longitudinal
While longitudinal waves oscillate (or vibrate) in the same direction they travel, transverse waves oscillate in a direction that is perpendicular to the direction they travel. For example, if a transverse wave is traveling horizontal, the wave will oscillate up and down. The shape of a transverse wave has high points called crests and low points called troughs. A wavelength is the distance from one crest to another crest.
What property of waves determines where they fall on the electromagnetic spectrum?
Wavelength
- Radio waves
- InfraRed
- Ultraviolet
- X-Rays
- Gamma Rays
Radio waves have very long wavelengths while X-rays and gamma rays have very short wavelengths. In the visible light spectrum, red light has longer wavelengths while purple light has shorter wavelengths.
Different types of electromagnetic waves have different properties. For example, X-rays can pass through certain solid materials like your skin. Gamma rays are a form of nuclear radiation that can cause radiation sickness, cancer, and even death to humans. But on the other end of the spectrum, the long wavelengths of radio waves enable them to travel long distances without being distorted. This makes radio waves ideal for communication. Cell phones, satellite TVs and radio, and wireless Internet all use different wavelengths of radio waves.
in what range of the electromagnetic spectrum does visible light fall
The wavelengths of visible light are in the nanometer range. One nanometer is 0.000000001 meters. So red light has a wavelength of 700 nanometers (0.0000007 meters) while violet light has a wavelength of 400 nanometers (0.0000004 meters).
How does radar work
Radar works by emitting a certain wavelength of radio wave. That radio wave travels at the speed of light to an object that reflects the wave back to the radar receiver. Based on the time it takes for the radio wave pulse to travel to the object and back, the radar can determine how far away the object is.
If space is a vacuum, how is it that electromagnetic waves can reach us from the sun?
Because electromagnetic waves do not require a medium to travel through.
