UART

Definitions

1. UART, or Universal Asynchronous Receiver-Transmitter, is a hardware communication protocol and device used for serial data transmission between two devices using just two data lines: TX (transmit) and RX (receive). Unlike synchronous protocols that require a shared clock signal, UART uses pre-agreed baud rates (like 9600 or 115200 bits per second), start bits, stop bits, and optional parity bits to synchronize communication. Each device's TX pin connects to the other device's RX pin. UART is one of the oldest and simplest serial communication standards, widely used in embedded systems, microcontrollers (like Arduino and Raspberry Pi), GPS modules, Bluetooth modules, and debugging interfaces. Many processors include dedicated UART hardware peripherals. In debugging, UART serial console output is often the first communication channel established when bringing up a new hardware platform. While slower than SPI or I2C for multi-device communication, UART's simplicity (two wires, no clock, no addressing) makes it ideal for point-to-point communication and remains ubiquitous in embedded development.

   In plain English: A piece of hardware that lets two devices talk to each other one bit at a time over a simple two-wire connection, like a walkie-talkie for chips.

   Example: "Plug a USB-to-UART adapter into the board's debug header and you get a serial console — first thing I do on any new embedded platform."

Related Terms

• GPIO
• I2C
• SPI
• Performance Counter
• RISC
• System Bus
• WebHID