cs - physical computing theory

not done: You should know how to add numbers in binary. You should know the four basic logical operators, their symbols and their truth tables.

what does CPU stand for

central processing unit

what is a cpu

primary/core component of a computer that acts as its control centre, that executes programs.

what does RAM stand for

random-access memory

what is RAM

holds data and instructions that the CPU is currently using

what is hard disk storage

stores data and instructions long term, when they are not being used

example of input device

keyboard, mouse

example of output device

printer, screen

what does a microprocessor use to control and manage multiple processes at the same time

operating system

other names for CPU

processor or microprocessor

what is a microcontroller

extremely small microcomputers that are entirely self-contained on a single chip.

A microcontroller is a tiny, single purpose computer. Microcontrollers do one thing well.

other name for microcontroller

embedded controller

microcontrollers are ________ inside some other device so that they can _________ of the product

 Microcontrollers are "embedded" inside some other device (often a consumer product) so that they can control the features or actions of the product

where is the microcontroller program stored

ROM

what does ROM stand for

read-only memory

microcontrollers are ____ to ___ task and to run ___ specific program

Microcontrollers are dedicated to one task and run one specific program

does microcontroller code generally change?

no, microcontroller code generally does not change

are microcontrollers often low or high power devices?

microcontrollers are often low-power devices,

how big is a microcontroller

a microcontroller is often small

how expensive is a microcontroller

often low cost

what is open source hardware

anyone can see the design specification of a physical object.

can be studied, modified, created and distributed by anyone.

what is open source software

the source code is available for development by anyone without having to purchase it. They can study, copy, modify and distribute new versions of it

define digital

digital systems are based on discrete signals

what is a discrete signal

generally, individually separate and distinct.

in computers, use binary digits (0s and 1s) to represent and manipulate data.

define analogue

based on continuous signals

analogue signal

a continuous signal in which one time-varying quantity (such as voltage, pressure, etc.)

define interface

a point at which two computer systems communicate/exchange information

what does IDE stand for

integrated development environment

what is an IDE

• it is a software package where a developer can enter/edit source code and compile it, run it, and debug it.

• software for building applications that combines common developer tools into a single graphical user interface (GUI)

• where software programs are written

what does USB stand for

universal serial bus

what is a USB

• a serial communication protocol, an industry standard that establishes specifications for cables, connectors, and protocols for connection, communication and power supply.

• allows data exchange and delivery of power between many various types of electronics.

• a serial data transmission protocol

• a hardware cable standard

what is a port (hardware)

a connection point/interface between a computer and an external/internal hardware device

• internal prts provide connections to hard drives or DVD drives

• external ports can connect printers/mice/other devices

the physical connection between two devices - often where a cable is plugged in to a computer

what is a port (software)

a virtual point where network connections start and end. these are software-based and managed by a computer’s operating system.

Ports allow computers to easily differentiate between different kinds of traffic: emails go to a different port than webpages, for instance, even though both reach a computer over the same Internet connection

Each port is numbered and associated with a specific process or service.

code for where something like an operating system decides how to deal with incoming traffic

what is a driver

a program that enables the communication between an operating system and a hardware/software application

lets the operating system and a device communicate

A small program which tells an operating system how to respond to a particular hardware that is attached to the system

what is a bootloader (on arduino)

 on Arduinos is a tiny piece of software that lets you upload the code you write to the Arduino itself.

bootloader (general)

a computer program that is responsible for booting a computer.

It contains the start-up instructions for a system.

are C based languages compiled or interpreted

compiled

is python compiled or interpreted

interpreted

compiled language feature

compiled languages compile the whole code at once and produce two things - an executable code file, and an error report. If there are no errors to report, the Arduino IDE will upload the executable file to the Arduino.

Executable files will run on the Arduino without the need for the Arduino IDE that you used on your laptop.

interpreted language feature

checks your code one line at a time and executes that line straight away. However, it stops completely, if it finds an error. The programmer has to fix that error before trying to run the code again.

The Python code runs through the IDE. This means you cannot simply package up the Python programme and run it on another machine. The other machine would have to have a Python IDE as well.

what is a protocol

an agreed set of communication signals between two electronic devices

they establish:
which ports will be used, which forms of error control, which method of encryption, if any, the rate of transfer of data

what is encryption

Encryption is a way to scramble data so that only authorized parties can unscramble it

define serial

bits of data are sent one after the other in series down a communication channel

serial port

a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time.

parallel communication

describes several bits being sent at the same time, on a link with several channels in parallel with each other.

why is parallel communication mainly found on very short communication channels of printed circuit boards- where channels are fixed in position

the communication can be unreliable over long distances, on short distances to ensure that the synchronisation of bits is likely to be undisturbed

which type of communication is faster? p/s

parallel is faster

which type of communication is slower? p/s

serial

what is serial communication

the process of sending data one bit at a time, sequentially, over a communication channel.

what is SYNCHRONISED serial communication

when the timing for when each bit is sent may be synchronised to the oscillations of an on-board clock (CLK)

what is ASYNCHRONOUS serial communication

more common, where data is packaged and sent across to another device as a packet.

files are broken up into many packets and reassembled at the receiving end.

what is the format of a packet

a frame

frame formats are defined by the protocol being used

order of a packet/frame as it is sent

start - data - parity(simple error checking) - stop

what does UART stand for

universal asynchronous receiver/transmitter protocol

what is UART for

interfaces the parallel communication lines carrying data from the processor on the board, with the serial communication lines to the system the Arduino is controlling.

what does DC stand for

direct current

what does DC mean/used for

direct current, which is current that only flows in one direction.

what uses DC

electronic systems use direct current, different from alternating current in the electric sockets on the wall

what is an actuator

a component/machine responsible for moving or controlling a mechanism/system

actuator example

valve, switch, motor

what can create a magnetic field (wire)

current flowing in a wire creates a magnetic field

define current

Current is the rate at which electrons flow past a point in a complete electrical circuit.

what is a stepper motor

The full 360^o of rotation is divided into a number of equal steps.

The motor can be sent signals which command it to turn through a precise number of steps

what is a rotor

the moving part of a motor

what is a stator

the static part of a motor

what is torque

a force that causes rotation

stepper motor use example

security cameras, dvd plates, image scanners, 3d printers

what is architecture

the way a computer is built

determines how memory is used, how programming instructions are executed and which codes are used for different processes

what is the motherboard

the main circuit board of the computer

what is a bit

the form of high/low voltage signals, represented as 1s or 0s

the smallest unit of data that a computer can process and store

what is a byte

8 bits

what is assembly code

uses mnemonics (3 letter shortened versions of a word/phrase) to represent the machine codes

what is a mnemonic (assembly code)

3-letter shortened versions of a word or expression, to represent machine code/assembly code instructions

machine code and assembly code are both ___ level languages

low level languages

python is a __ level language

high level language

what is the only language a computer can actually execute

machine code (0s and 1s)

what is an instruction set

the set of machine code instructions for a computer

a set of codes that the computer processor can understand.

why are instruction sets needed

When computers are manufactured, there are subtle differences in the ways different manufacturers build them. This means that the machine code for each manufacturer’s computer might be unique to that computer. The machine code for an Apple Mac won’t run on a DELL computer, or a Samsung watch.

are high level languages are machine independent?

yes, because they have translators that translate the high level code into the machine code for the compute the program will be run on

to program in a HIGH or LOW level language, you need to know the instruction set of the computer that will run the code

LOW level

HIGH or LOW level languages are easier for humans to understand

HIGH level languages

HIGH or LOW level languages are easier to debug

HIGH level languages

HIGH or LOW level languages are machine dependent

LOW level languages

HIGH or LOW level languages execute faster because they relate directly to the instruction set of the computer

LOW level languages

Because low level languages work directly with individual instruction sets, they can take advantage of machine specific functions

true

what is a translator

program language processors that convert one programming language to another.

what is an assembler (translator)

one assembly code instruction (one mnemonic) translates to one machine code instruction. When assembly code is prepared for execution, it is translated by an assembler into machine code. And this machine code can then be executed by the computer processor

are high level languages platform dependent or independent

high level languages (like python) are platform-independent

they are not machine specific

With high level languages, one command often translates to many machine code instructions.

what is an interpreter

interpreters translate a programme (source code) into machine code line by line.

they stop as soon as they find an error, and that error has to be fixed before it continues interpreting - makes interpreting faster to develop working programs.

what is source code

Any program written in a high level language

what is a compiler

translates a programme (source code) from start to finish. it prepares the whole source code to be ready to be executed machine code programme.

a compiler can detect syntax errors and run-time errors in the source codes

benefit of a compiler

you can sent it to any machine and it will run, does not need the IDE of the source language to be installed.

useful for programs that might be sold, like games/apps

what does CAD stand for

computer aided design

example of CAD

fusion360, tinker cad, sketch up

what is CAD

computer software to design new products in 3D

what does CAM stand for

computer aided manufacture

examples of CAD

laser cutter, 3D printer

what is CAD

using computers to control machines to undertake the production of goods

benefits of CAM

fast and accurate, machines can carry on where human workers would get tired/need rest, can reduce material wastage

what does a laser cutter do

can cut and engrave materials like cork, wood, plastic, cloths, cardboard etc.

what does a laser cutter consist of (two systems)

one produces a high-powered laser beam

move a laser head with a computer (computer numerical control - CNC)