Arduino- Serial communication

Arduino- Serial communication

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  Arduino Based Applications Part-2 By JawaherA.Fadhil B.SC in Electronics Engineering M.Tech in Computer Engineering University of Duhok College of Science CS Department
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  Serial Communication 2
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  Introducing Serial Communication Theword serial comes from the way data is transmitted; serial devices send bits one at a time on a single wire. This is something that you have seen before; it is like a telephone call. Both users pick up the telephone and a single wire connects them together. While serial devices send bits on a single wire, parallel devices send multiple bits on multiple wires. Although parallel communications can be faster than serial, they were often more expensive, requiring more wires. There are also speed limitations due to physical limitations of conductive wiring. The next figure shows the difference between serial and parallel communications. 3
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  Introducing Serial Communication 4 Serialversus parallel
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  Introducing Serial Communication Serialports are extremely simple. This simplicity is one reason why they are used so often. Data is sent on one wire, the transmit wire (TX), and received on another, the receive wire (RX). On the other side of the cable, it is connected to another computer with a TX pin and an RX pin. Inside the cable itself, the TX and RX wires are inverted. The TX pin on one side is connected to the RX pin on the other side. This is illustrated in Figure. 5 Transmit and receive wires
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  Introducing Serial Communication Arduinosuse serial ports for communicating with computers and other devices. The USB port of an Arduino is used for serial communication with a computer, with the added advantage that USB can also be used to power the device. USB also has the advantage of auto-configuring most of the parameters. Some Arduinos have other hardware serial ports, enabling communication with other devices. The USB communication is sent to Arduino pins 0 and 1, meaning that those pins are reserved if your device must communicate with a computer. 6
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  Starting a SerialConnection To Start a Serial Connection you must first do some basic configuration. To do this, you use the begin function of the Serial object. Typically, 9,600 is an appropriate speed for communicating. You are free to use any speed you want as long as both devices are operating at the same speed. void setup() { Serial.begin(9600); // Opens the serial port } Serial configuration is normally done in setup() because devices tend to not change the speed at which they communicate over time. 7
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  Sending Text To senddata to the serial device , use the function print(). The data to be printed can be in any format. Serial.print("Hello, world"); // Output an entire string Serial.print('!'); // Output a single character 8 Serial Communication-writing You need the following components: • Arduino Uno • USB cable
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  Serial Communication-writing void setup() { pinMode(13, OUTPUT); Serial.begin(9600); // sets data rate to 9600 bps } void loop() { digitalWrite(13, HIGH); Serial.println("LED is On"); delay(1000); digitalWrite(13, LOW); Serial.println("LED is Off"); delay(1000); } 9
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  Serial Communication-Reading Arduinos canalso receive data. Receiving data can be used for many projects; computers can send data, for example, to control the brightness of an LED. To read data from the serial device , use the function Serial.read( ); int ledPin=13; int value; void setup() { Serial.begin(9600); pinMode(ledPin,OUTPUT); } 10
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  Serial Communication-Reading void loop() {value = Serial.read(); if (value == '1') { digitalWrite(ledPin,HIGH); } else if (value == '0') { digitalWrite(ledPin,LOW); } } 11
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  Reference James A. Langbridge,”Arduino sketches tools and techniques for programming wizardry”,2015. 12
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