Serial communication is a way for data transmission over long distances. Commonly associated with RS232 and TTLserial, it enables Arduino and other microcontrollers to communicate with your computer or other serial devices. Though technology has advanced and we currently have faster means of data transfer such as USB, serial communication is still widely seen and applicable in our lives.
How does Serial Communication work?
- Serial communicating first involves two serial devices, each having two serial pins;
· The receiver, RX
· The transmitter, TX
Both devices are then wired by connecting wires from the master device’s TX to the listener’s RX line
Devices communicate serially through signal methods, popular ones being- TTL serial, RS-232, RS 485.
Hardware Implementations of Serial Communication:-
- RS232- RS-232 (Recommended Standard 232) telecommunications standard is the first serial communication protocol that is widely used as a communication method for computers and devices by serial ports. Similar to your microcontroller serial signals, it transmits data a bit at one time. In RS-232 standard a logic high ('1') is represented by a negative voltage – anywhere from -3 to -25V – while a logic low ('0') transmits a positive voltage that can be anywhere from +3 to +25V.
RS232 works by connecting Data Transmission Equipment (DTE) and Data Communication Equipment (DCE), which has pins like TXD, RXD, and RTS&CTS.
· TXD: Transmitter
· RXD: Receiver
· RTS: Request to Send
· CTS: Clear to Send
· GND: Ground
2. TTL: UARTs transmit one bit at a time at a specified data rate (i.e. 9600bps, 115200bps, etc.). This method of serial communicationis referred as TTL serial (transistor-transistor logic). Serial communication at a TTL level will always remain between the limits of 0V and Vcc, which is often 5V or 3.3V. A logic high ('1') is represented by Vcc, while a logic low ('0') is 0V.
3. RS485: The RS485 also known as TIA-485 (-A) or EIA-485 is a serial communication method for computers and devices similar to the RS232. RS485 allows multiple devices of up to 32 to communicate at a half-duplex on a single pair of wire plus a ground wire at distances up to 1200 meters. RS485is used commonly as a protocol for POS, industrial, telecom, and especially in noisy environments due to its wide common-mode range that enables data transmission over long cable lengths in noisy environments.
4. USB: The Universal Serial Bus (USB) standard was developed to define communication protocols, including cables and connectors, between computers and electronic devices such as printers and scanners. As the number of devices multiplied in quantity and types, the USB port was adopted as the basic connection portal. USB 2.0 offers transfer rates of 480 Mbps, and USB 3.0 offers transfer rates of 4.8 Gbps — 10 times faster. USB 3.0 uses two unidirectional data paths, one to receive data and the other to transmit
Serial interface Modules:
· RS232 to TTL serial Interface Module- It usesMAX232IC for conversion. It can be used to program STC MCU, NXP MCU, Renesas MCU, STM32 MCU, N+-2EC MCU.
- USB TO TTL Module: It features Single-Chip USB to UART Data Transfer - Integrated USB transceiver. On-chip voltage regulator - 3.3 V output (CP2102) - 3.45 V output (CP2109) - 100% pin and software compatible with CP2101.
Buy: USB TO TTL Module
- USB TO RS485 Converter: The USB-RS485 module provides an easy to use RS485 interface by means of a Virtual Com Port on the user's system.
- MAX 485 to TTL Converter: This converter lets you send and receive data using the RS485 network from your Arduino/microcontroller.
- CP 2102 USB to Serial Converter Board: This is the CP2102 Breakout Board. This board provides RS232serial communication interface to computers with aUSB port.