Glossary of Terms
GUI
Graphical User Interface - screen representation where user interacts with the computer. Uses graphical objects
like buttons, sliders, areas to enter data and some way to send screen inputs to the computer.
HMI
Human Man Interface - the idea of optimizing how to operate a device by optimizing how and where to locate
controls.
IDE
Integrated Development Environment - a GUI to provide a way to write source code, debug, and compile using
plain text to be converted to machine code.
OOP
Object Oriented Programming - simply the idea of creating a clone of a data structure that act like a data type
and retain the operability of the original Class the describes the data structures properties.
API
Application Program Interface - defined protocols to describe an interface between to pieces of software that
will allow interoperability. May take the form of a small program its self.
Camel Case
A method to write condensed variable names as in camelCase, alternating capitalizing the first letter of the next
word without a space.
Function
A function is a defined process to accomplish a task. Its purpose is to only have a task that may be used many
time only have to be written out once. Data may be passed into the function and a result may be return or not.
Variables define within a function are 'destroyed' upon leaving the function. Applying changes to variables
external to a function can be done by reference. Static variables can be defined that retain a value between
function calls.
Ohm's Law
Defines the relationship between voltage, current, and resistance. V=IR
Kirchhoff's Laws
1. Voltage drop across elements of a series circuit add to the total of the source voltage of the circuit
2. Current entering a node must equal the current leaving a node
Conventional Current Flow
Define current flow from negative to positive potential, when in fact for physics electrons flow from negative
(cathode) to positive (anode) potential. It is still used since electronics component symbols show conventional
current.
TTL
Transistor to Transistor Logic - foundation of digital electronics consisting of bipolar transistor that define logic
elements of AND, OR, XOR and their complements. Originally known as 74xx series operating with 0 volts
meaning logic false and +5 volts meaning logic true.
CMOS
Later application in silicon of TTL logic, but used complementary metal oxide technology to vastly reduce the
current use for portable electronic equipment.
Bipolar
Use of two silicon diode junctions to create a device that could amplify an input. Used in digital logic to cut off
for a 'zero' and to saturate an output for a 'one'.
DIP
Dual Inline Package - fundamental packaging type of two sets of pins running down the length of an integrated
circuit to be place on circuit board holes for soldering.
SMA
Surface Mount Assembly - or integrated circuits without through-hole pins, but soldered directly to the surface
of a printed circuit board.
IC
Integrated circuit - silicon based electronic circuit that can be highly miniaturized and printed into layers of
silicon doped materials.
Breadboard
Term derived from connecting experimental circuit on a wooden board by hammering nails into a pattern and
running wire and component between them. These boards were refined into highly organized set of hole to
place components for experimental purposes.
Resistor - ohm
Fundamental element of electronic circuits that restricts the flow of current and establishes the relationship
between voltage and current.
Capacitor - Farad
Fundamental element of electronic circuits that stores electrostatic potential or a collection of electrons as a
voltage.
Inductor - Henry
Fundamental element of electronic circuits that stores energy in the form of a magnetic field around a coil of
wire.
Volts
Measure of electrostatic potential energy. Symbol is V or E
Amps
Number of electrons passing a point within a current defined as one Coulomb of electron per second. Symbol is
I.
Resistance
Directly proportional to voltage and current as in R=V/I
Impedance
A form of resistance to current flow caused by reactive elements of capacitance and inductance.
Frequency - Hertz
Cycles per second of alternating amplitude of energy measured in Hertz.
Engineering Units
Engineering unit vary is sets of 1000 or 1/1000, since values of typical component have such a large range of
values.
Multimeter
A handy portable meter that measures voltage, current, and resistance. Many meters add of features of
measuring capacitance or temperature.
Potentiometer
A resistor that is formed into a circular form with a center, movable conductor that sweeps around the resistive
element to vary the value of resistance measure from the center tap to ends of the element. If a voltage is
applied across the pot, he center tap forms a voltage divider with a varying level from the low end to the high
end. If one end of a pot is disconnected the device is called a rheostat, which is essentially
a variable resistor.
FET
Field effect transistor. A three pin unipolar device where an electrostatic field on one pin is used to control the
flow of electrons that would otherwise move freely between two other pins. It operates in theory similar to
vacuum tubes. Main advantage is extremely high input impedance (100 M ohms). They make excellent
switches and are low noise devices. Disadvantages is susceptibility to electrostatic discharge, since the barrier
layer inside is very thin and they have a relatively low gain-bandwidth product compared to bipolar transistors.
BJT
Bipolar junction transistors. Commonly used as amplifiers, oscillators, and integrated circuits. BJTs can be used
as very high frequency amplifiers. Basically two diode junctions back-to-back, three pin device where the base
emitter junction, if forward biased, will cause a much larger current to flow from the collector out through the
emitter in the NPN type and cause current to flow into the emitter junction and out the collector in the PNP
version.
H-bridge
Arrangement of four switches (FET) where the device to be controlled (usually a DC motor) forms the cross
arm of an H shape with switches in the arms of the H. Thus when opposite switches are “on”, and the two others
are “off”, current flows one way in the device. When this arrangement is reversed, the current will flow in the
opposite direction in the device.
URL
Uniform Resource Locator is a human friendly statement that can be used to look up the more difficult to
remember address of a location on a network. The Internet uses IP addresses, which also are a code for
ultimately a series of binary digits that form a unique location address that can found by a router.
RISC
Reduced Instruction Set Computer. Meaning, the complexity of using variable length instructions to do complex
operations have been reduce to instructions that are all the same length and therefore move much more quickly
through a computer’s data path. Now these complex operations are broken down into more fundamental tasks.
In general, when this approach was adopted, computer speeds increased dramatically for the same benchmarks.