Input And Output Devices (Copy)
IGCSE / O Level Computer Science Cheat Sheet
Topic: 3.2 Input and Output Devices
🖱️ Input Devices
- Devices that send data to a computer
| Device | Function |
|---|---|
| Keyboard | Enters text and commands |
| Mouse (optical) | Controls on-screen pointer |
| Microphone | Captures sound as digital input |
| Barcode scanner | Reads product barcodes |
| QR code scanner | Scans matrix-style codes |
| Digital camera | Captures still images |
| Touch screen | Detects user touch (resistive, capacitive, IR) |
| 2D/3D scanners | Converts physical images/objects to digital |
🔁 Output Devices
- Devices that display or output data from a computer
| Device | Function |
|---|---|
| Monitor (LCD/LED) | Displays visual output |
| Inkjet printer | Sprays tiny ink droplets for printing |
| Laser printer | Uses toner and laser for fast, high-quality print |
| Speaker | Outputs sound |
| Projector (LCD/DLP) | Projects video to a surface |
| Actuator | Converts signals to physical movement |
| 3D printer | Produces physical objects from 3D models |
🌡️ Sensors (Input Devices)
Used in automated systems to detect physical changes.
| Sensor Type | Measures |
|---|---|
| Temperature | Heat |
| Humidity | Moisture in air |
| Light | Brightness levels |
| Infra-red | Motion / heat detection |
| Proximity | Distance to nearby objects |
| Accelerometer | Movement / orientation |
| Pressure | Applied force |
| Gas | Gas concentration (e.g. CO2) |
| Magnetic field | Magnetic flux |
| Moisture | Water content |
| pH | Acidity/alkalinity of solutions |
| Flow | Movement of liquids/gases |
| Level | Liquid level in a container |
| Acoustic | Sound waves |
📊 Sensor Applications
| Area | Example Use |
|---|---|
| Industry | Detect gas leaks, control production |
| Agriculture | Soil moisture, weather sensing |
| Medicine | Heart rate, temperature monitors |
| Home | Motion-sensing lights, smart thermostats |
| Transport | Parking sensors, crash detection |
🎮 Input + Output Device
| Device | Acts as Both | Example Use |
|---|---|---|
| Touch screen | Input + Output | Phones, ATMs, POS systems |