1. RS-232
Description: One of the oldest and most widely used serial communication standards.
Features:
Full-duplex communication.
Maximum cable length: ~15 meters (50 feet).
Baud rate: Up to 115.2 kbps (typically).
Voltage levels: ±3V to ±15V for logic states.
Applications: Industrial equipment, legacy computer peripherals (e.g., modems, printers).
2. RS-485
Description: A multi-point communication standard designed for industrial use.
Features:
Half-duplex communication.
Supports up to 32 devices on a single bus (expandable with repeaters).
Maximum cable length: ~1,200 meters (4,000 feet) at lower baud rates.
Baud rate: Up to 10 Mbps (short distances).
Differential signaling for noise immunity.
Applications: Industrial automation, building management systems, motor control.
3. RS-422
Description: Similar to RS-485 but designed for point-to-point communication.
Features:
Full-duplex communication.
Maximum cable length: ~1,200 meters (4,000 feet).
Baud rate: Up to 10 Mbps (short distances).
Uses differential signaling for reduced electromagnetic interference (EMI).
Applications: Data acquisition systems, industrial equipment, telecommunications.
4. Universal Serial Bus (USB)
Description: A widely adopted standard for connecting peripherals to computers and other devices.
Features:
High-speed data transfer (up to 40 Gbps for USB 4.0).
Plug-and-play capability.
Power delivery up to 240W (USB PD 3.1).
Hot-swappable support.
Applications: External storage devices, keyboards, mice, cameras, and more.
5. UART (Universal Asynchronous Receiver-Transmitter)
Description: A hardware module that facilitates asynchronous serial communication.
Features:
Point-to-point communication.
Baud rate: Varies by implementation, typically up to 1 Mbps.
Supports various data frame formats (start bit, data bits, parity, stop bit).
Applications: Microcontrollers, GPS modules, Bluetooth modules.
6. SPI (Serial Peripheral Interface)
Description: A synchronous serial communication protocol commonly used for short-distance communication.
Features:
Full-duplex communication.
Master-slave architecture (1 master, multiple slaves).
Clock speeds: Typically up to 50 MHz.
Requires multiple lines: SCLK, MOSI, MISO, CS.
Applications: Sensors, displays, SD cards, embedded systems.