Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

active high signal: a signal that is considered asserted when it is HIGH or 1.
active low signal: a signal that is considered asserted when it is LOW or 0.
address bus: a set of signal lines between the processor and memory or I/O that carry the address (location) of a memory or I/O access. The address space of the processor (the maximum number of memory locations that can potentially be accessed) is determined by the number of these signal lines.
address strobe: a signal output from the processor that indicates when a valid address is present on the address lines.
algorithm: a sequence of steps used to solve a particular problem.
AC (alternating current): an electric current that alternates its direction of flow. The frequency of alternating current is measured in hertz, or cycles per second.
ampere: a unit used to measure current. One ampere corresponds to the amount of current flowing through a resistance of one ohm at one volt potential difference.
ampere hours: a measurement of battery cell capacity that equals the number of hours a cell can supply a certain amount of current before its voltage drops below a predetermined threshold value.
amplitude: the magnitude of the signals in a waveform, usually expressed in voltage.
analog: characterized by a continuously variable range of signal levels, as opposed to digital, where signal magnitude can only take on discrete values.
analog multiplexer: a component that selects an analog output signal from a number of analog inputs. An address value sent to the multiplexer determines which of the inputs is selected. See multiplexer and analog
AND gate: a type of logic gate that outputs a 1 (true) only when all inputs are 1. AND gates have two or more inputs. See also NAND gate.
anode: a positive electrode.
argument: a value or expression that is passed to a function.
array: a sequential list of data values of the same type.
ASCII: pronounced `askee,' an acronym for American Standard Code for Information Interchange, a coding scheme that assigns numeric values to letters, numbers, punctuation marks, and other characters. For example, the letter A is represented by the number 65 in ASCII.
assembly language: a type of low-level programming language in which each statement corresponds directly to a single processor-specific instruction. Assembly language programs can be written either by hand or generated by a compiler. A program known as an assembler translates the assembly language into object code.

axle: the shaft on which a wheel or gear is mounted.

B

back electromagnetic force (back-emf): a potential difference caused by the turning of a motor. When a motor is turned, it essentially becomes a generator, and produces a voltage difference at its terminals. Resistance to changes in this voltage difference produces resistance to the turning of the motor.
battery: a device that uses a chemical reaction to produce electrical energy.
bend sensor: a resistive sensor whose resistance is proportional to how much the sensor is bent. The higher the bend, the higher the resistance.
bias: a voltage applied to a transistor or other electronic device in order to establish a reference level for its operation.
binary: binary refers to the base-2 number system, in which values are expressed as sequences of binary digits (bits). Thus, the only allowable numerals in a binary number are 0 and 1.
binary program: another name for the object code translation of an assembly program.
bit: short for binary digit; the smallest unit of information handled by a computer. Each bit represents either a 0 or 1.
bitwise operators: Operators that perform functions on specific bits in a byte (testing, setting, or shifting) rather than the byte as a whole.
block: a section of code in which local variables can be declared.
board, or printed circuit board: a broad term referring to a flat circuit board used to hold chips and other electronic components as well as to provide connections between the components. The largest board used; in ELEC 201 is called the RoboBoard.
Boolean logic: a type of algebraic logic where every answer is either true or false; digital processors use Boolean logic extensively, since each answer can be represented by a bit, which is either 1 or 0, true or false. Some programming languages support a Boolean data type with predetermined values for true and false; others use integer data types to implement Boolean values, where zero equals false and non-zero values equal true.
bound: the upper or lower limit in a permitted range of values.
break: a special signal used to interrupt a program or transmission.
bridge rectifier: a circuit that assists in converting alternating current to direct current.
buffer: section of memory set aside for temporary storage.
bug: any problem in a piece of hardware or software that keeps it from running properly.
bus: a set of signal lines (wires) used to transfer information between several components in parallel.
bus contention: a situation that occurs when two or more components try to simultaneously access the same bus.
byte: a unit of information consisting of 8 bits.

calibrate

to compare an instrument or device against a standard to determine its accuracy, or to provide a reference level.

call

a statement that causes the code in a function or subroutine to be executed.

call-by-reference

one method of passing variables to a function in which the address of the desired variable is passed as an argument to the function rather than a copy of its value. Code within the function can read and modify the original variable using this address.

call-by-value

another method of passing a variable to a function. A copy of the variable is passed as an argument to the function. Since this is only a copy, the function cannot modify the value of the original variable.

capacitor

a component that can store electrical energy. It is made up of two conductive surfaces separated by an insulating material known as a dielectric.

case sensitive

distinguishes between upper and lower case. The IC Programming Language, for example, is case sensitive.

cathode

a negative electrode.

cell

a (see battery).

cell capacity

the amount of current that a cell can supply for a period of time, usually measured in ampere-hours.

character

any single text symbol such as a letter, number, or punctuation mark.

character string

a sequence of consecutive characters.

clicking on

in terms of a computer, refers to moving the cursor over an object to be selected (such as a button), and pushing the mouse button to activate the object.

clock

refers to the clock on the RoboBoard, based around a crystal-controlled oscillator circuit. The crystal is set to resonate at a specific frequency and produces an analog sine wave. The frequency generated by the clock is the master frequency of the board.

closed-loop control

method of controlling the robot where the action being performed sends information back to the microprocessor about the action's effect on the robot's state.

code

the a computer program, or section of a program.

coercing

to change a value from one data type to another so that it can be used in a particular function.

cold solder joint

an improperly soldered connection caused by failure to adequately heat the joint during soldering. Cold solder joints appear dull and do not conduct electricity well.

color code

a system of colors used to indicate the electrical value of a component. Resistors have bands of color on them to indicate their resistance. Also, see Resistor Color Code Table.

command line

the line on a computer screen on which commands are entered.
see resistor pack.

compile-time error

an error in the source code of a program that is detected while it is being compiled.

compiler

a program that translates high-level programming languages into instructions called machine or object code that a machine can understand.

component side

the side of a board on which components are placed.

CPU(Central Processing Unit)

the chip inside a computer responsible for essential control and computational functions. Also called a ``processor'', the RoboBoard's is a M68HC11, or simply the 'HC11.

crash

the result of a run-time error. This usually causes the system to hang or lock-up.

data bus

a set of signal lines connecting a processor, its memory, and peripherals that carry the data associated with a memory access. The address of the access is provided by the address bus.

DC motor

a motor designed for direct current operation; easy to reverse and control speed.

de-referencing

The process of accessing a variable through a pointer.

debugging

the process of diagnosing and correcting problems.

decoder

a multiple-input, multiple-output logic device that converts coded inputs into coded outputs, where the input and output codes are different. A 3-to-8 decoder, for example, uses a three bit binary input to select one of eight output lines. Also called a ``demultiplexer''.

default value

a value automatically determined for something, such as a variable, if no other user-specified value is assigned to it.

desoldering pump

a tool used to remove solder from a joint.

desoldering wick

resin-coated copper braid used to remove solder.

dielectric

the insulating material between plates of a capacitor or between any two parts in an electric circuit.

digital

characterized by representation as discrete values, as opposed to analog .

digital input/output

digital signal lines used to transfer discrete information between the processor and devices such as sensors, motors, and lamps.

diode

a device that passes current only in one direction, sometimes called a rectifier.

DIP(dual-inline package)

the standard bug-like package characteristic of most low density computer chips. Its pins are arranged in two parallel rows.

DIP socket

a socket that holds chips, so that chips themselves are not actually soldered to the board. As with chips, the sockets require attention to proper orientation when mounting.

DIP switch

small toggle switches on a board that are set to control various aspects of the board's operation.

discharge curve

a curve showing the voltage as a battery discharges. Different types of battery have characteristically different discharge curves.

download

to receive information (usually a file) from another computer.

driver

a piece of software that tells the computer how to communicate or operate with a certain piece of hardware or software.

dynamic RAM

random access memory whose stored data must be refreshed periodically by reading the data and writing it back to the same location. If this is not done, the data will be lost.

encoder

a see multiplexer

EPROM

/ee-prom/Erasable Programmable Read-Only Memory; A type of non-volatile memory chip that can be programmed electrically and erased by exposing the chip to ultraviolet light.

EEPROM

/ee-ee-prom/ ``Electrically Erasable Programmable Read- Only Memory'' - A type of non-volatile memory chip that can be both programmed and erased electrically.

electrode

one of the plates of a battery or electrolytic capacitor.

electrolytic capacitor

a fixed value capacitor in which the dielectric is a thin film formed on the surface of an aluminum electrode by a liquid or paste electrolyte (a substance that conducts electricity).

electromotive force

a voltage or potential.

execution

the performance of one or more instructions, usually involving the loading of machine code into memory and the carrying out of the specified instructions.

farad

a unit of capacitance.

feedback

output from a system that is returned to the same system for the purposes of making control decisions.

feed forward control

a type of open loop control where the control signal is a function of some parameters measured in advance.

female connector

a type of connector with one or more receptacles for the insertion of pins.

female socket header

a type of female connector whose receptacles are arranged in two adjacent rows, usually used for cables.

float

a type of variable in floating-point (exponential) form.

footprint

the pattern on a printed circuit board to which the component leads are mated. See also pad.

for loop

a programming command that executes a section of code a specified number of times.

frequency

how often something happens, measured in hertz, which is one cycle or vibration per second.

function call

a reference to a function in a section of code 68HC11 that executes the function.

function declaration

the ``title'' of a function that lists its type (void, int, float, etc.) as well as any variables that may be passed to that function.

gate

an electronic switch that follows a rule of Boolean logic, such as AND, OR, or NOT.

gauss

a measurement of magnetic flux density.

gear

a toothed wheel used to transfer mechanical energy.

gear reduction

The technique of attaching a small gear to a larger gear to increase torque at the expense of rotation speed.

girder

a beam.

global variable

a variable whose value can be accessed and modified by any statement in a program. In other words, it is visible to the entire program (see local variable).

ground

a connection between an electric circuit and the earth, the common point (e.g. 0V) to which all signals in a circuit are referenced.

H-bridge

a circuit commonly used to drive motors.

Hall effect sensor

an electromagnetic sensor that detects changes in electromagnetic fields.

heat shrink tubing

rubber tubing that is used to protect soldered joints. It is initially large and flexible, but shrinks and becomes stiff when heated.

heatsink

a device that absorbs and dissipates heat produced by an electrical component; used to prevent overheating.

hexadecimal

the base-16 number system. In order to count to 32 in hex, the following would be the sequence of numbers: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F, 10, etc.

hypertext

a type of information structure that is non-sequential and associative, linked in such a way so that when more information is sought about a word, simply clicking on that word in the document brings it up.

if/else statement

a form of programming statement. When the if expression is true, then the statement following the if expression is executed; when that expression is false, the else statement is executed.

incandescent lamp

a lamp with a filament that heats and emits white light when current runs through it.

induction

the process by which an object is electrified, magnetized, or given an induced voltage by exposing it to a magnetic field.

inductor

a device possessing the ability to store energy in the form of a magnetic field; an inductor passes direct current, but blocks alternating current to a degree, depending on its frequency.

infrared

range of invisible light radiation frequencies lying between visible red and radio waves on the spectrum.

initialize

to prepare something for use. A computer initializes itself each time it is started up.

insulator

a non-conductive material, used to separate elements of circuits; rubber, glass, ceramic, and plastic are all good insulators.

integrated circuit

also called an IC, an integrated circuit consists of a single chip (usually silicon) with many components such as transistors and resistors fabricated on it. Integrated circuits contain anywhere from a few tens to many millions of components. Most of the ICs on the RoboBoard are MSI (medium scale integration), chips that contain anywhere from 20 to 200 logic gates.

Interactive C

a version of the C programming language used in ELEC 201; interactive suggests that the user has added control over what is going on.

internal resistance

the natural resistance of a battery, generator, or circuit component, which determines the

maximum rate at which power can be drawn.

interpreter

a piece of software that directly executes source code without first compiling and storing the code in an intermediate format.

interrupt

a special processor function that halts normal

program execution in response to some event such as a timer expiration or successful transmission of a character to an I/O device. When the interrupt is encountered, the processor executes a special interrupt handler routine to process the event.

interrupt-driven

a programming method in which code is only executed in response to events that cause interrupts.

inverter

a logical function that returns the opposite of the input. Equivalent to a NOT gate. Also a device that changes direct current into alternating current.

isolated element resistor pack

see resistor pack.

latch

circuit or circuit element used to maintain a particular state, such as logical true or false, on or off.

lead

a connecting wire, such as a test lead, battery lead, etc.

lead-acid cell

common type of rechargeable battery cell in which sulfuric acid reacts with lead to produce electricity.

LED(light-emitting diode)

a semi-conductor device that converts electrical energy into light.

LCD(liquid crystal display)

a display comprised of a polymer, a thin grid of electrodes, and two polarizing filters with their polarizing planes at right angles to each other. Light is either passed through the filters or blocked by aligning the molecules by means of the electric field from the electrodes. Blocking the light produces black regions on the display to create an image.

Lenz's Law

a principle which states that induced current flows in the opposite direction as the motion that generated it.

library

a file containing standard functions that may be used by a program. Library functions usually perform very specific tasks, and using them can simplify work when a particular function needs to be carried out repeatedly in a program.

local binding

a term meaning a variable is defined only within the context of a particular function, not the whole program.

local variable

a variable declared inside a function. These variables can only be referenced by statements inside the block where they are declared.

loop

a set of commands that repeat until a certain condition is reached.

machine code

(See object code).

magnetic shaft encoder

a device that uses a magnetic sensor to detect rotation.

male connector

a type of connector with one or more pins, as opposed to receptacles.

male socket header

a type of male connector whose pins are arranged in one or more rows, usually used for cables.

master

an SPI participant that controls data flow to other SPI systems.

megahertz (MHz)

a frequency measure corresponding to a signal that oscillates at one million cycles per second. Megahertz is often used when referring to the clock speed of a computer.

memory effect

a phenomenon observed in rechargeable nickel cadmium cells where cells only partially discharged before recharging tend to ``remember'' the level of discharge. These cells eventually become usable only to that level of discharge.

memory enable control line

the signal directly asserted by the processor when a memory module is to be accessed. This signal enables or ``turns on'' the memory chip and allows data to be read from or written to the memory module.

microprocessor

(See CPU).

master in slave out

abbreviated MISO, this data line supplies the output data from a slave to the master. No more than one slave can transmit data at any given time.

modulated infrared light

infrared light made to vary in intensity, in accordance with variations in another signal.

modulate

to vary the amplitude, frequency, or phase of a carrier wave, usually to transmit information.

master out slave in

abbreviated MOSI, this data line supplies the output data from the master that is shifted into the input(s) of the slave(s).

multimeter

test instrument with a number of different ranges for measuring current, voltage, and resistance.

multiplexer

a circuit that allows only one of several digital inputs to be slected (and output) at a time.

multi-tasking

a mode of operation where more than one sequence of computation is active at the same time.

NAND gate

a type of logic gate that outputs a 0 only when all inputs are 1.

native language (also: host language)

language supported by a particular computer system (the host) in the absence of software to create the support. Strictly speaking, native language refers to the central processing unit's (CPU's) machine language, but the term is sometimes applied to a high-level language specifically supported by the operating system.

negative feedback loop

a type of control where the feedback helps to correct an error, making the degree of error smaller.

negative logic

logic that uses active low signals. See also active low.

nickel cadmium cell

type of rechargeable cell with moderate power density and low internal resistance.

nominal cell voltage

the voltage produced by the chemical reactions in an electrochemical cell.

non-volatile memory

storage system that does not lose information when its power is turned off.

NOR gate

a type of logic gate that returns a 1 only when all inputs are 0.

NOT gate

a type of logic gate that returns the opposite of its input.

null

a character having no meaning, in the sense that it does not cause any action and holds no meaningful value. Null can be used for many purposes, such as receiving test output in a program, to separate blocks of information, or to terminate strings.

nybble

a four bit hexadecimal digit equal to half of a byte. Also spelled nibble.

object code

code that is generated by a compiler or assembler from the source code of a program (in ELEC 201, the IC code is the source code). Object code generally refers to the instructions that can be directly executed by the central processing unit (CPU).

Ohm's law

a fundamental electrical law expressing the relationship between voltage, current, and resistance in a DC circuit: voltage (V) = current (I)�resistance (R) .

ohm

The unit of electrical resistance. One ohm corresponds to the resistance at which one volt can maintain one ampere of current.

ohmmeter

instrument for measuring resistance.

open-loop control

method of controlling the robot where the action being performed sends no feedback to the microprocessor on the action's effect on the robot's state; open-loop control works best when a robot functions under very reliable conditions.

OR gate

a type of logic gate that returns a 0 only when all inputs are 0.

oscilloscope

a device that displays on a screen (cathode ray tube) how a voltage or current signal varies over time.

pad

a conductive patch on the surface of a printed circuit board to which leads are connected.

p-code (pseudo code)

machine language for a hypothetical processor. P-code requires a software interpreter for execution.

parallel (circuit) connection

way of connecting two or more components such that the two ends of each component are connected together. Thus, the voltage is the same across all of the components, but the current is divided between them (See also series circuit).

Figure E.1: Parallel Connection of Components A,B, and C
$\begin{figure} \fbox {\centerline{\psfig{figure=glossary/parallel.ps}}}\end{figure}$

parallel port

a port that allows data to flow in more than one bit at a time, typically with one separate wire for each bit.

PCB

printed circuit board; an epoxy glass and metal composite on which circuits are etched and to which active, passive and hardware components are attached.

peripheral

in computer terms, any piece of the computer apart from the CPU and memory.

persistent global variable

type of global variable that keeps its value even when the robot is turned off or reset. Downloading will usually destroy the values of persistent globals.

phase

relative measurement describing the temporal relationship between two waves with the same frequency. Phase is measured in degrees, and one full oscillation cycle has 360 degrees. One way to think of phase: If two pendulums are swinging at the same frequency and are in the same position at the same instant, then they are in phase with each other.

phase-locked loop

a device that keeps the phases of two signals constant, relative to each other.

photocell

a light-sensitive cell whose resistance changes when exposed to light.

phototransistor

a semiconductor controlled by light rather than an electric current.

picofarad (pF)

1 �10^-12 Farads .

Piezo beeper

a component containing a crystal that makes noise when an electric current is applied.

pin

slender prongs, usually referring to the contacts sticking out of a male connector or the ``legs'' on a chip.

PLCC (plastic leadless chip carrier)

a variation of an LCC, which is a method of mounting chips on boards using contacts instead of leg-like pins. The chip simply rests in a socket that has contacts on its base for completing the connection.

pointer

a variable that contains a memory address. Usually this address is the location of another variable in memory. Pointer variables much be declared as such, and the variable type must match the type of the variable being ``pointed'' to.

polarity

the sign of the potential (voltage) between two points in a circuit. When a potential difference exists between two points, one end has a positive polarity and the other one, negative polarity. Electrons flow from negative to positive, but by convention, current is considered to flow from positive to negative.

polarized component

a circuit component that must be installed with its leads in a particular orientation with respect to the direction of current flow (or polarity) of the circuit. Examples of such components: diodes, rectifiers, and some capacitors.

polarizing filter

transparent piece of glass that only lets light waves vibrating in a certain direction pass through.

positive logic

logic in which active high signals are used. See also active high.

potential

the difference produced by an imbalance in the charge distribution that causes the movement of charge carriers in a conductor. Also called voltage.

potentiometer

(commonly called a pot) a circuit element that can be adjusted to provide varying amounts of resistance.

power density

the capacity per unit weight of a battery cell.

precedence of operators

the default order in which mathematical operations are performed.

process identification number

(pid) the number assigned to a process when it is called using the IC function call start process(). This number can be used to later kill the process.

process table

a table used by the processor to keep track of all running processes.

program counter

a register that contains the address of the next instruction to be executed.

program stack

memory used by a process to pass arguments for function calls, to store local variables, and to store return addresses from function calls. The size of the stack is defined at the time the process is created.

pseudo-code

see p-code.

pull-up resistor

a resistor connected to the supply voltage to provide drive current to a gate.

pulse width modulation

method of encoding information by varying the shape of a series of pulses. The unmodulated signal consists of a continuous pulse train of constant frequency, duration, and amplitude; during modulation, pulse durations (or widths of pulses) are changed to reflect the information being encoded.

RAM (random-access memory)

memory that can be read and written by the microprocessor and other hardware devices. Storage locations can be accessed in any order (hence ``random access'' RAM is usually volatile, meaning its contents are lost when power is removed.

rated output

power, voltage, or current a device will provide when operating under normal circumstances.

ROM (read-only memory)

memory containing instructions or data that can be read but not modified. As a general term, ROM can refer to PROM or EPROM.

read-write control line

line that controls whether a device is to perform a read function or write function.

rectifier (a.k.a. diode)

a circuit component that passes current in one direction and blocks current flow in the other direction. A rectifier is used to convert alternating current into direct current.

recursion

the act of a function calling itself.

resistance

the quality that impedes the flow of electric current. All materials have some degree of inherent resistance. Substances with low resistance (such as metals) conduct electricity well and are called conductors. Substances with very high resistance are called insulators or non-conductors.

resistor

circuit component designed to provide a specific amount of resistance to current flow.

resistor package

Resistor packs are flat, rectangular packages with anywhere from six to ten leads. Two basic types of resistor packs are isolated element containing discrete resistors, and common terminal that contain resistors with one pin tied together and the other pin free.

return value

the value that a function returns when it has finished executing.

RS-232

An international standard for serial communication

run-time errors

errors that occur in a program while it is executing (as opposed to compiling).

schematic

a diagram that shows the electrical connections of an electronic component by means of symbols used to represent the parts and lines to represent wires connecting the parts.

semiconductor

material with generally high resistive properties, but which conducts under special conditions. The semiconductors used to make ICs are generally fabricated from the element silicon.

serial communication

transmission of information between computers and peripheral devices one bit at a time over a single line. Serial communication requires that both sender and receiver use the same communication parameters.

serial port

a port that sends bits one at a time, in a single stream, typically consisting of a line for sending data, one for receiving, and one or more other lines for regulating the transmissions over the send and receive lines. A common type is an RS-232 port.

serial clock

abbreviated SCK, a control line driven by a master SPI system that regulates the flow of data bits. The master may transmit data at different baud rates. The SCK line cycles once for each bit that is transmitted.

series (circuit) connection

a circuit in which components are connected together end to end. Although current passes through each of the components, voltage is divided among them. (See also parallel connection).

**Figure E.2:** Series Connection of Components A,B, and C
$\begin{figure} \fbox {\centerline{\psfig{figure=glossary/series.ps}}}\end{figure}$

servo motor

motor whose output shaft does not rotate freely, as in a DC motor, but moves to a certain angular position.

shaft

a bar supporting, or transmitting motion to, a mechanical part.

short circuit

low-resistance connection across a voltage source, or between the sides of a circuit or line. Also called simply a ``short'', these typically result in excessive (and potentially damaging) current flow.

signal demodulation

the process of extracting the frequency component from a modulated signal

SIP(single in-line package)

a package type in which pins are arrange in a single line. Some of the resistor packs (RSIPs) on the RoboBoard are of this package type.

slave

an SPI participant that responds passively to data transfer actions initiated by the SPI system master.

slave select

abbreviated SS, a control line that allows slave SPI systems to be turned on and off with hardware control.

slotted optical switch

a component containing a light source and a sensor aimed at each other. The sensor detects when the light source is not blocked, say by a slotted wheel turning between the two.

socket

mounting device for plug-in coils, plug-in capacitors, plug-in resistors and crystals having holes with spring clips arranged to fit and grip the terminal prongs of the component being plugged in.

solder

an alloy of tin and lead that melts at a fairly low temperature and is used for making permanent electrical connections between parts and wires.

soldering iron

a device for applying heat to a joint, melting the solder so that it creates a permanent joint.

SPI

serial peripheral interface.

stack

region of memory in which programs store status data, such as function call return addresses, passed parameters, and sometimes local variables. The program, microprocessor and operating system can all maintain one or more separate stacks.

stack pointer

a register that keeps track of the current location in the stack.

statement

an individual C command. For example, var1 += var2;.

static RAM

a kind of RAM that can hold a logic high or logic low state as long as there is electricity applied. The logic states are lost in static RAM only if erased by the programmer or if the electricity is turned off. Static RAM does not have to be refreshed as long as the power is on.

stalled state

the state when a motor is producing the maximum amount of torque, but is not rotating.

stepper motor

a motor whose rotation is in discrete steps rather than continuous movement.

SMD(surface-mounted device)

a type of package for an integrated circuit that, as its name implies, is mounted on the surface of the printed circuit board (as opposed to its pins being inserted through the PCB).

string

an one dimensional array of characters.

tantalum capacitor

a type of polarized capacitor.

task manager

tracks the progress of and provides necessary resources for separate tasks running on one processor.

terminal

in electronics, a point that can be physically connected to something else, usually by a wire, to form an electrical connection

threshold

a point at which an effect can be seen. For example, the threshold voltage of a transistor is the minimum voltage that must be applied to the base before any current will flow through the transistor; a test value.

ticks

units of time.

timeout

a loop exit condition for which a loop is exited after a predetermined amount of time if the condition is not met.

tinning

covering the soldering iron tip or the tip of a wire with solder.

toggle

as a noun, a device with two states or a program option that can be turned on or off using the same action (like a mouse click); as a verb, to toggle is to switch back and forth between two states.

tolerance band

colored band on a component indicating the permissible variation from the rated or assigned value.

torque

the rotary force produced on a motor's output shaft

transceiver

component that can both transmit and receive signals.

transducer

a device that converts energy from one form to another, retaining the amplitude variations of the energy being converted. Examples include a microphone, which converts acoustical energy into electrical energy; a loudspeaker, that does the reverse; a photocell that converts light energy to electrical energy.

transistor

a circuit component (usually with three leads) that can serve several functions- amplifier, switch, or oscillator, among others. The three leads of a transistor are the emitter, base, and collector, and in the most common mode of operation, a large current flow between the collector and emitter terminals is controlled by a small current applied to the third terminal, the base. The current can be turned on and off, causing the transistor to behave as a switch.

transparent

used to describe a change that is made, or an operation that is performed, that has no effect with respect to the user.

unloaded speed: the speed at which a motor runs when there is nothing connected to the shaft.

V

value types: the various formats for data to be used in a program; the value type must be specified when a variable is declared. Value types in IC include integer (int), floating-point (float) , and character (char).
variable resistor: a resistor with a sliding contact that permits changing the resistance value.
value mantissa: the decimal part of a floating-point number.
volatile memory: a storage system that loses its data when removed from a power supply.
voltage divider: two resistors in series connected across a voltage source. The voltage at the common centerpoint is a fraction of the total applied voltage, determined by the resistor values.
voltage drop: voltage developed between terminals of a component by current flow through the resistance of that component.

W

while loop: another type of loop in C, whose form is while(condition == true) statement; A statement can range from a single instruction to a block of instructions that repeat. The condition may be any expression, and true is any non-zero value. The loop iterates while the condition is true. When the condition becomes false, program execution continues with the line following the loop code.