RS232 circuit and interfacing with Microcontroller
RS232 is a asynchronous serial communication protocol widely used in computers and digital systems. It is called asynchronous because there is no separate synchronizing clock signal as there are in other serial protocols like SPI and I2C. The protocol is such that it automatically synchronize itself. We can use RS232 to easily create a data link between our MCU based projects and standard PC. In serial communication the whole data unit, say a byte is transmitted one bit at a time . While in parallel transmission the whole data unit , say a byte (8bits) are transmitted at once. Obviously serial transmission requires a single wire while parallel transfer requires as many wires as there are in our data unit. So parallel transfer is used to transfer data within short range (e.g. inside the computer between graphic card and CPU) while serial transfer is preferable in long range. As in serial transmission only one wire is used for data transfer. Its logic level changes according t...