UART

Definition

UART, or Universal Asynchronous Receiver-Transmitter, is a hardware communication protocol that allows for asynchronous serial communication between devices. It converts parallel data from a microcontroller into serial data for transmission and vice versa, making it crucial for many embedded systems applications such as data transfer between microcontrollers and sensors or other peripherals.

5 Must Know Facts For Your Next Test

1. UART is typically used for low-speed, short-distance communications, making it ideal for interfacing with sensors and other peripherals in embedded systems.
2. Each UART consists of a transmitter and a receiver, which handle the conversion of parallel data to serial and back again, enabling two-way communication.
3. The configuration of UART includes settings like baud rate, data bits, stop bits, and parity, which must match on both communicating devices for proper communication.
4. UART can be found in various embedded systems applications such as GPS modules, Bluetooth modules, and even within microcontrollers themselves.
5. Unlike synchronous communication protocols, UART does not require a clock signal for data transfer, which simplifies the design and implementation of many embedded systems.

Review Questions

• How does UART facilitate communication between embedded systems and external devices?
  • UART enables communication by converting parallel data from microcontrollers into serial data that can be transmitted over a single wire. This method reduces the number of connections needed for communication. By sending data asynchronously, UART allows devices to communicate without needing to be synchronized by a clock signal. This makes it particularly useful for interfacing with various sensors and peripherals where low-speed communication is sufficient.
• What are the key configuration parameters of UART that must be matched on both communicating devices to ensure successful data transmission?
  • The key configuration parameters of UART include baud rate, data bits, stop bits, and parity. The baud rate determines how fast the data is sent; the number of data bits specifies how much information is contained in each transmitted unit; stop bits signal the end of a data packet; and parity provides a way to detect errors in transmission. If these parameters do not match on both devices, it can lead to miscommunication or data loss.
• Evaluate the advantages and limitations of using UART compared to other communication protocols in embedded systems.
  • UART has several advantages, such as simplicity in design and implementation due to its asynchronous nature and fewer wiring requirements. It's particularly effective for short-distance communications at lower speeds. However, its limitations include a lower maximum speed compared to synchronous protocols and its inability to support multiple devices on a single bus without additional management. In contrast, protocols like I2C or SPI can handle higher speeds and allow multiple devices but come with increased complexity in their configuration.

Related terms

Serial Communication: A method of transferring data one bit at a time over a single channel or wire, often used in embedded systems to communicate with various devices.

RS-232:

A standard for serial communication transmission of data, often used in conjunction with UART to define the physical connections and signal voltages.

Baud Rate: The rate at which information is transferred in a communication channel, typically measured in bits per second (bps), and is a crucial parameter in configuring UART communication.