[2017.6 Digital Twin] Arduino - Communication

Arduino - Communication

Today I will continue study arduino. At first, I should figure out how to use the Arduino to contact with other device. I have seen, the Arduino IDE has a serial window. It just use the USB cable connect with computer. So I can Make an inference, that one the Arduino boeard, it includes already a USB-Serial chip. Arduino use it download program and also can use that to communicate.

On the website, there are also 2 pins works als normal serial, pins 0 (RX) and 1 (TX)
https://www.arduino.cc/en/Reference/Serial

from the schematic we can see, the usb connect with a ATMEGA16U, I think it works as a USB-serial adapter. And then, it connect with core chip ATMEGA 328P-PU and the input pin0 and pin1, That means, the pin0 pin1 and usb-serial are work parallelly.

So I can directly use UBS port to communicate with arduino!


Here are the function of the SERIAL

Serial.begin()

Serial.begin(speed)
Serial.begin(speed, config)

speed: in bits per second (baud) - long rates: 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600, or 115200.
config: sets data, parity, and stop bits. Valid values are :

SERIAL_8N1 (the default)

....https://www.arduino.cc/en/Serial/Begin

also there are serial1,serial2,serial3 but for arduino uno, there are only serial.

EG.

  Serial.begin(9600);

  Serial.println("Hello Computer");

end()

Description

Disables serial communication, allowing the RX and TX pins to be used for general input and output. To re-enable serial communication, call Serial.begin().

available()

Description

Get the number of bytes (characters) available for reading from the serial port. This is data that's already arrived and stored in the serial receive buffer (which holds 64 bytes). available() inherits from the Stream utility class.

void loop() {

// send data only when you receive data:
if (Serial.available() > 0) {
// read the incoming byte:
incomingByte = Serial.read();

// say what you got:
Serial.print("I received: ");
Serial.println(incomingByte, DEC);
}
}

read()

Description

Reads incoming serial data. read() inherits from the Stream utility class.

by the way, the number from Serialavailable() will decrease by 1.

peek()

Description

Returns the next byte (character) of incoming serial data without removing it from the internal serial buffer. That is, successive calls to peek() will return the same character, as will the next call to read(). peek() inherits from the Streamutility class.

flush()

Description

Waits for the transmission of outgoing serial data to complete. (Prior to Arduino 1.0, this instead removed any buffered incoming serial data.)

print()

Serial.print(78) gives "78"
Serial.print(1.23456) gives "1.23"
Serial.print('N') gives "N"
Serial.print("Hello world.") gives "Hello world."

Serial.print(78, BIN) gives "1001110"
Serial.print(78, OCT) gives "116"
Serial.print(78, DEC) gives "78"
Serial.print(78, HEX) gives "4E"
Serial.println(1.23456, 0) gives "1"
Serial.println(1.23456, 2) gives "1.23"
Serial.println(1.23456, 4) gives "1.2346"

println() has a return at the end of line.

write()

Description

Writes binary data to the serial port. This data is sent as a byte or series of bytes; to send the characters representing the digits of a number use the print() function instead.

Serial.write(val)
Serial.write(str)
Serial.write(buf, len)

val: a value to send as a single byte
str: a string to send as a series of bytes

buf: an array to send as a series of bytes
len: the length of the buffer

serialEvent()

Description

Called when data is available. Use Serial.read() to capture this data.

!!!This function is usefull. It can make serialread function out of the main loop.