Both connections can be used at the same time (full duplex), in alternating order (half duplex) or stand-alone (simplex).

Each connection transmits bits in only one direction from the TX (transmit) pin of one end point to the RX (receive) pin of the other end point. HardwareĪ serial link over UART consists of two connections for the transfer of single bits. This cables are often referred to as FTDI cable, named after the FTDI chip used for the USB to UART conversion. Such adaptors come in the form of a small PCB (Printed Circuit Board) or a completely integrated USB cable. Nevertheless there is a solution available in the form of a USB to UART bridge. These ports have been replaced by USB (Universal Serial Bus) to connect peripherals to a PC. Recent PC models usually don’t have a serial port (RS-232) any more. The symbol rate of serial links is still measured today in Baud. It is named after its inventor Jean-Maurice-Émile Baudot (1845 – 1903), a french telegraph engineer. Teletypewriters used a specific bit representation for each character known as the Baudot code. Teletypewriter => TTY => /dev/ttyS0 or /dev/ttyUSB0 as the device name on Unix based systems. This legacy remains in the name of serial interfaces on Unix systems: The teletypewriter sent out each key press as a character to a modem which then transmitted it further as serial bits via a telephone line. One of the first applications for serial data communication was the connection between teletypewriters and modems. Some examples illustrate how you can set up serial connections with your Pi and how to implement them in your Java applications by using the RXTX library. This post provides a short introduction in UART (Universal Asynchronous Receiver Transmitter), the basic form of serial interface. In an earlier post I introduced the Raspberry Pi as a great platform for tinkering. Application scenarios include firmware update, logging/debugging, data streaming and many more. A serial interface is also a common way to connect a PC to an embedded system. Today, serial interfaces can be found inside myriads of embedded systems where they transfer data between different components.

Its origins date back to the 1960’s when serial communication was used between teletypewriters and modems.

Serial communication is one of the ancient technologies in computing that is still relevant today.

Java serial com port examples