Asynchronous serial communication with start and stop bits.
UART transmits bytes asynchronously with start bit, 8 data bits, optional parity and stop bit at agreed baud rate (9600, 115200). Needs TX, RX and ground; RS-232/RS-485 levels for distance. Errors: framing, overrun, parity.
Sending 'A' (0x41) at 115200 baud takes about 87 µs per byte.
UART is the simplest common serial link, and it connects microcontrollers to modules, debug consoles and GPS receivers.
Asynchronous serial communication with start and stop bits.
UART is the simplest common serial link, and it connects microcontrollers to modules, debug consoles and GPS receivers.
They mark the beginning and end of each byte in asynchronous transmission, so the receiver can align its sampling to the data.
Without a shared baud rate and frame format, the receiver samples at the wrong times and reads garbage.
Typical applications include sending debug messages from a microcontroller to a PC terminal, connecting a GPS module that sends NMEA sentences and communicating with a Bluetooth module over a serial port.
Study "PWM" first (topic 63 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
Baud tolerance about ±2%. Flow control RTS/CTS. Used for debug consoles.
Sending 'A' (0x41) at 115200 baud takes about 87 µs per byte.
The next topic is "SPI", which builds directly on this one.
It is classed as Intermediate in Electronics & Embedded (topic 64 of 104). It is an intermediate topic. Work through the beginner topics in Electronics & Embedded first.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.