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Serial.readBytes()
설명
Serial.readBytes()직렬 포트에서 아래 구문의 매개변수중 하나인 buffer로 문자를 읽습니다. 이 함수는 결정된 길이를 읽었거나 시간 초과되면 종료됩니다 (Serial.setTimeout() 참조).
Serial.readBytes() 시리얼 버퍼에있는 문자 수를 반환합니다. 0은 유효한 데이터가 없음을 의미합니다.
Serial.readBytes()은 Stream 유틸리티 클래스에서 상속합니다.
문법
Serial.readBytes(buffer, length)
매개변수
- buffer: 바이트를 저장할 버퍼. char또는 배열 byte (char[] or byte[]).
- length: 읽을 바이트 수 (int).
반환값
- 시리얼 버퍼에 있는 바이트 수입니다 (size_t).
예제 코드
const int BUFFER_SIZE = 50;
char buf[BUFFER_SIZE];
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// check if data is available
if (Serial.available() > 0) {
// read the incoming bytes:
int rlen = Serial.readBytes(buf, BUFFER_SIZE);
// prints the received data
Serial.print("I received: ");
for(int i = 0; i < rlen; i++)
Serial.print(buf[i]);
}
}
- Type "HELLO" on Serial Monitor and click Send button:
COM6
Autoscroll
Clear output
9600 baud
Newline
- 시리얼 모니터에 결과:
COM6
I received: HELLO
Autoscroll
Clear output
9600 baud
Newline
※ 주의 및 경고:
- Serial.readBytes() may read a stream of bytes in multiple times (resulting in multiple fragments). To read a stream of bytes at one time, there are two ways:
- Based on the delimiter: Use Serial.readBytesUntil() with delimiter.
- Based on the fixed length: Wait until the fixed number of bytes is available. for example:
- Make sure that the read length does NOT exceed the buffer size. The below is the best practice:
- Serial functions are not only used for the communication between an Arduino board and Serial Monitor of Arduino IDE but also used for the communication between:
- An Arduino board and other Arduino board
- An Arduino board and other sensors/devices
- An Arduino board and computer (any Serial software on computer)
const int BUFFER_SIZE = 5;
char buf[BUFFER_SIZE];
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// check if data is available
if (Serial.available() >= BUFFER_SIZE) {
// read the incoming bytes:
Serial.readBytes(buf, BUFFER_SIZE);
// TODO: PROCESS THE INCOMING DATA HERE
}
}
const int BUFFER_SIZE = 5;
char buf[BUFFER_SIZE]; // application buffer
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// check if data is available
int rxlen = Serial.available(); // number of bytes available in Serial buffer
if (rxlen > 0) {
int rlen; // number of bytes to read
if (rxlen > BUFFER_SIZE) // check if the data exceeds the buffer size
rlen = BUFFER_SIZE; // if yes, read BUFFER_SIZE bytes. The remaining will be read in the next time
else
rlen = rxlen;
// read the incoming bytes:
rlen = Serial.readBytes(buf, rlen);
// TODO: PROCESS THE INCOMING DATA HERE
}
}
더보기
- 언어 : Arduino - Serial
- 언어 : Serial.available()
- 언어 : Serial.begin()
- 언어 : Serial.end()
- 언어 : Serial.find()
- 언어 : Serial.findUntil()
- 언어 : Serial.flush()
- 언어 : if(Serial)
- 언어 : Serial.parseFloat()
- 언어 : Serial.parseInt()
- 언어 : Serial.peek()
- 언어 : Serial.print()
- 언어 : Serial.println()
- 언어 : Serial.read()
- 언어 : Serial.readString()
- 언어 : serialEvent()
- 언어 : Serial.setTimeout()
- 언어 : Serial.write()
- 언어 : stream
- 언어 : stream.readBytes()
※ ARDUINO BUY RECOMMENDATION
| Arduino UNO R3 | |
| Arduino Starter Kit |
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