Microcontrollers, sensors, logic gates ยท Data types, statistics, charts ยท 63 terms
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Microcontrollers, sensors, logic gates and digital circuits.
3A computer system built into a larger device to perform a specific task, often with limited memory, power and user interface.
The computer inside a microwave, washing machine, or car's anti-lock brakes. It's not a general computer you use for browsing โ it lives inside the device and does one job.
A small computer on a single chip used to control hardware such as sensors, LEDs and motors.
A small programmable microcontroller board used in schools for physical computing and embedded systems.
A block-based and JavaScript coding environment commonly used with the micro:bit. Useful for embedded systems tasks in class, but not a core exam definition.
An input device that detects a physical quantity such as light, temperature, movement or moisture.
Your eyes are sensors โ they detect light. A thermometer is a sensor that detects temperature. Sensors convert real-world information into data a computer can process.
An output device that causes a physical action, such as a motor, buzzer or servo.
Your muscles are actuators โ they receive signals from your brain (the processor) and move. A motor, buzzer, or LED receives a signal and does something physical in the real world.
An input with discrete states, usually on/off, 1/0, True/False.
An input that can vary continuously over a range, such as light level or temperature.
A dimmer light switch is analogue โ it can be anywhere from fully off to fully bright. A regular on/off light switch is digital.
An output signal with discrete states, often HIGH/LOW or on/off. Example: turning an LED on or off.
The process of converting a continuous analogue signal into digital values a computer can process.
A connection point on a microcontroller used to send or receive electrical signals.
A complete path through which electric current can flow.
Like a closed loop of road โ cars (current) can only travel if the road is continuous. Break the loop and traffic stops.
Electrical potential difference; a "push" that can cause current to flow in a circuit. Measured in volts (V).
Water pressure in a pipe. Higher pressure (voltage) pushes more water (current) through. No pressure = no flow.
The flow of electric charge in a circuit, measured in amperes (A).
Opposition to the flow of current, measured in ohms (ฮฉ).
A component that limits current flow in a circuit, protecting sensitive components like LEDs.
A component that stores electrical energy/charge and can release it.
A semiconductor component used as an electronic switch or amplifier; a basic building block of logic circuits and processors.
A transistor is like a tiny tap controlled by electricity. A small electrical signal at the tap handle controls whether a much larger current can flow. Billions of these microscopic "taps" make up a modern CPU.
A chip containing many electronic components/transistors on a single piece of semiconductor material.
Instead of soldering thousands of individual transistors onto a circuit board, an IC puts all of them on a piece of silicon the size of a fingernail โ making computers small and cheap.
An electronic/computational component that performs a Boolean operation on one or more inputs to produce an output.
A logic gate is a tiny decision-maker made of transistors. It looks at its inputs and decides its output using a rule (AND, OR, NOT etc.).
A table listing every possible input combination and the corresponding output of a Boolean expression or logic circuit.
Very common short question. Know AND, OR, NOT truth tables off by heart.
| Gate | Rule | Example |
|---|---|---|
| AND | Output is 1 only when all inputs are 1 | Door opens only if key AND code are correct |
| OR | Output is 1 when at least one input is 1 | Alarm sounds if motion OR smoke detected |
| NOT | Output is the opposite of the input (inverter) | If light is ON โ output is OFF |
| XOR | Output is 1 when inputs are different | Output 1 if inputs are 0,1 or 1,0 โ not if both same |
Outputs 1/True only when all inputs are 1/True.
Outputs 1/True when at least one input is 1/True.
Outputs the opposite of its input. Also called an inverter.
Outputs 1/True when inputs are different. Useful for half adders.
A logic circuit that adds two binary bits and produces a sum and carry output.
A logic circuit that adds two binary bits plus a carry-in, producing a sum and carry-out.
A way to simulate variable output by switching a digital signal on and off rapidly with different duty cycles. Used for LEDs/motors.
Like controlling light brightness by rapidly blinking a bulb on and off โ the longer it stays on each cycle, the brighter it appears overall.
Data vs information, cleaning, statistics, and charts.
4Raw facts, values or observations that can be stored and processed by a computer.
A thermometer reading of "18" is data โ just a number. On its own, it tells you little.
Data that has been processed or given context so it becomes meaningful.
"The temperature in Cork today is 18ยฐC, which is 5ยฐC warmer than average for May" โ now it's information. Context has been added.
A collection of related data values, usually organised in records, tables or files.
A complete set of fields about one item/entity in a dataset or database table. In a table, a record is a row.
One category/attribute in a record, such as name, age or score. In a table, a field is a column.
A single value in a dataset, such as one person's age or one temperature reading.
Comma-Separated Values: a plain-text format where rows of data are stored line by line and fields are separated by commas.
Like a spreadsheet saved as plain text. Each row is a record, each comma separates a field. Very common for datasets โ Excel, Python and databases can all open them.
JavaScript Object Notation: a text-based data format using key-value pairs and lists, often used by APIs.
Application Programming Interface: a way for one program/system to request data or services from another.
A waiter in a restaurant. You (your program) tell the waiter (API) what you want. The waiter goes to the kitchen (external service), gets it, and brings it back. You don't need to know how the kitchen works.
Data that is publicly available for people to use, reuse and share, often from governments or organisations.
The process of collecting, cleaning, analysing and interpreting data to find patterns, answer questions or support decisions.
A testable prediction or proposed explanation that can be investigated using data.
"Students who sleep more than 8 hours get better exam results" โ that's a hypothesis. You'd then collect data to test whether it's true.
Finding and fixing/removing problems in data, such as missing values, duplicates, inconsistent formats or outliers.
Like proofreading an essay โ you find typos (errors), missing sentences (missing values), and repeated paragraphs (duplicates), then fix them before submitting.
Checking that input data is reasonable and follows rules before it is accepted or processed.
A website form that rejects your age if you type "200" or a negative number โ it validates that the value makes sense.
Checking that data has been entered or copied accurately from its source. Example: double entry or visual checking.
A data item that is blank or absent when a value is expected.
A repeated record that appears more than once in a dataset. Must be identified and removed during data cleaning.
A value that is unusual compared with the rest of the data and may be an error or a genuine exceptional case.
Do not automatically delete outliers without justification โ they could be genuine data points worth investigating.
When similar data is written in different formats, such as dates recorded as "01/05/2024" in some rows and "May 1, 2024" in others.
The arithmetic average: total of values divided by the number of values.
The middle value when values are sorted. If there are two middle values, the median is their mean.
Median = Meddle. Sort first, then find the middle.
The most frequently occurring value in a dataset. Can be more than one mode.
Mode = Most Often. The value that appears most.
The difference between the highest and lowest values in a dataset.
The number of times a value or category occurs in a dataset.
Representing data graphically, such as using bar charts, line graphs, pie charts or scatter plots.
Charts must have: title, axis labels (with units), and a legend where appropriate.
A chart using separate bars to compare categories or discrete values. Good for category comparisons.
A chart using points connected by lines to show change over time or sequence. Good for trends over time.
A circular chart divided into sectors showing parts of a whole. Only use when parts sum to a meaningful whole.
A chart showing points for pairs of values, useful for spotting relationships/correlation between two variables.
Text that identifies what a chart axis represents and often its unit. Marks can be lost for unclear graphs.
A key that explains colours/lines/categories in a chart. Use when a graph has multiple series.
A Python library used for data analysis and tabular data manipulation.
A Python library used to create charts and visualisations.
A Python library used for numerical computation and arrays. Useful for advanced analytics but not usually essential at LC level.
Python visualisation libraries sometimes used for charts in coursework. Useful alternatives to Matplotlib but not required to memorise for the exam.