What is UART?

UART stands for Universal Asynchronous Receiver/Transmitter. It’s a serial communication interface/protocol like SPI and I2C, it can be a physical circuit in a microcontroller, or a stand-alone IC. A UART’s main purpose is to transmit and receive serial data. One of the best things about UART Bluetooth modules is that it only uses two wires to transmit data between devices.

UARTs transmit data asynchronously, which means there is no clock signal to synchronize the output of bits from the transmitting UART to the sampling of bits by the receiving UART. Instead of a clock signal, the transmitting UART adds start and stop bits to the data packet being transferred. These bits define the beginning and end of the data packet so the receiving UART knows when to start reading the bits.

When the receiving UART detects a start bit, it starts to read the incoming bits at a specific frequency known as the baud rate. Baud rate is a measure of the speed of data transfer, expressed in bits per second (bps). Both UARTs must operate at about the same baud rate. The baud rate between the transmitting and receiving UARTs can only differ by about ±5% before the timing of bits gets too far off.

what pins are in UART?

VCC: Power supply pin, usually 3.3v

GND: Ground pin

RX: Receive data pin

TX: Transmit data pin

Currently, the most popular HCI is the UART and USB connection, UART is generally more popular because its performance and data throughput level are comparable to USB interfaces, and the transmission protocol is relatively simple, which reduces software overhead and is a more cost-effective full hardware solution.

UART interface can work with an off-the-shelf Bluetooth module.

All of Feasycom’s Bluetooth modules support UART interface by default. We also supply TTL serial port board for UART communication. It’s very convenient and easy for developers to test their products.

For UART communication Bluetooth modules details, you could contact with Feasycom sales team directly.