Glossary · Automation fundamentals, platforms and components
Universal asynchronous receiver-transmitter (UART)
Also known as: UART
German: UART
In embedded electronics, a universal asynchronous receiver-transmitter (UART) is a hardware interface that sends and receives serial data frames without a shared clock, each frame framed by a start bit, data bits, an optional parity bit and stop bits, at a baud rate agreed by both sides.
- Automation components
In one sentence
A UART sends and receives serial data frames without a clock line, using start and stop bits at a baud rate both sides agree on.
Example
A stepper driver IC is configured over a single-wire UART, so a small controller can address several drivers on one line.
How it applies
- Engineering: A UART works at logic level on a board. For longer cables, a transceiver converts the signals to a physical layer such as RS-232 or RS-485; the UART framing stays the same.
- Commissioning: Baud rate, data bits, parity and stop bits (for example 115200 8N1) must match on both sides; a mismatch produces garbage or no response.
- Operation: Framing and parity errors point to wrong settings, noise or clock deviations.
- Documentation: Give the complete frame setting, the voltage level, the pinout (TX of one side to RX of the other) and the protocol carried on top. Don't call a UART port "RS-232" when it runs at logic level: connecting it to an RS-232 port can damage it.