1. Analog vs Digital Signal
1.1 Analog Signals
Analog signals are signals that are continuous — meaning their values can change smoothly without jumps, representing physical quantities from the real world such as temperature, light, sound, and pressure.
Characteristics of analog signals:
- Values can be any real value within a range.
- Sensitive to noise (electromagnetic interference, heat, etc.).
- Interact directly with the real world (sensors, microphones, photodiodes).
1.2 Digital Signals
Digital signals are signals that are discrete — their values can only be in two conditions: HIGH (1) or LOW (0), usually in the form of a square wave.
Characteristics of digital signals:
- Only have two values: 0 and 1 (LOW and HIGH).
- Nearly immune to noise.
- Used in data transmission and processing within electronic devices.
- Use less energy.
1.3 Comparison of Analog and Digital
| Aspect | Analog Signal | Digital Signal |
|---|---|---|
| Nature | Continuous | Discrete |
| Values | All real values | 0 or 1 |
| Noise Resistance | Low | Very high |
| Primary Use | Sensors, real-world actuators | Data processing, computing |
| Examples | Microphone sound, LDR output, sensor temperature | Serial data, clock signals, PWM |
| Energy Consumption | Relatively larger | More efficient |
Both complement each other: analog signals capture real-world phenomena accurately, then are converted to digital so they can be processed by computers/microcontrollers.