我正在使用两个Arduino板,使用NewSoftSerial和RF收发器相互发送纯文本字符串。
每个字符串可能有20-30个字符长度。如何将
每个字符串可能有20-30个字符长度。如何将
Serial.read()
转换为字符串,以便我可以执行if x == "testing statements"
等操作?Serial.read()
转换为字符串,以便我可以执行if x == "testing statements"
等操作?无限字符串读取:
String content = "";
char character;
while(Serial.available()) {
character = Serial.read();
content.concat(character);
}
if (content != "") {
Serial.println(content);
}
void setup() {
Serial.begin(9600); // 初始化串口
}
void loop()
{
String content = "";
char character;
while(Serial.available()) {
character = Serial.read();
content.concat(character);
delay (10); // 添加延迟以避免打印每个字符在新行上。
}
if (content != "") {
Serial.println(content);
}
}
- So Over Itreturn(content);
而不是Serial.println()
。否则,您将陷入无限循环,因为它会捕获函数打印到串行端口的任何内容并尝试重新处理它。 - depwl9992content.trim()
方法。 - Yakob Ubaidi来自于Help with Serial.Read()获取字符串:
char inData[20]; // Allocate some space for the string
char inChar = -1; // Where to store the character read
byte index = 0; // Index into array; where to store the character
void setup() {
Serial.begin(9600);
Serial.write("Power On");
}
char Comp(char* This) {
while (Serial.available() > 0) // Don't read unless there
// you know there is data
{
if(index < 19) // One less than the size of the array
{
inChar = Serial.read(); // Read a character
inData[index] = inChar; // Store it
index++; // Increment where to write next
inData[index] = '\0'; // Null terminate the string
}
}
if (strcmp(inData, This) == 0) {
for (int i=0; i<19; i++) {
inData[i] = 0;
}
index = 0;
return(0);
}
else {
return(1);
}
}
void loop()
{
if (Comp("m1 on") == 0) {
Serial.write("Motor 1 -> Online\n");
}
if (Comp("m1 off") == 0) {
Serial.write("Motor 1 -> Offline\n");
}
}
inData.trim()
。如果我们正在使用Arduino控制台,则会有换行符。这个https://dev59.com/zYHba4cB1Zd3GeqPXOEp对我很有用。 - Yakob Ubaidi你可以使用 Serial.readString()
和Serial.readStringUntil()
从Arduino的串行端口解析字符串。
你也可以使用Serial.parseInt()
从串行端口读取整数值。
int x;
String str;
void loop()
{
if(Serial.available() > 0)
{
str = Serial.readStringUntil('\n');
x = Serial.parseInt();
}
}
要通过串口发送的值为my string\n5
,结果将是str = "my string"
和x = 5
Serial.readStringUntil()
解决了所有问题,并使代码更易读!谢谢! - Eddie Fletcher我曾经也问过同样的问题,经过一些调查研究,我找到了类似的东西。
这对我来说非常好用。我用它来远程控制我的Arduino。
// Buffer to store incoming commands from serial port
String inData;
void setup() {
Serial.begin(9600);
Serial.println("Serial conection started, waiting for instructions...");
}
void loop() {
while (Serial.available() > 0)
{
char recieved = Serial.read();
inData += recieved;
// Process message when new line character is recieved
if (recieved == '\n')
{
Serial.print("Arduino Received: ");
Serial.print(inData);
// You can put some if and else here to process the message juste like that:
if(inData == "+++\n"){ // DON'T forget to add "\n" at the end of the string.
Serial.println("OK. Press h for help.");
}
inData = ""; // Clear recieved buffer
}
}
}
char data [21];
int number_of_bytes_received;
if(Serial.available() > 0)
{
number_of_bytes_received = Serial.readBytesUntil (13,data,20); // read bytes (max. 20) from buffer, untill <CR> (13). store bytes in data. count the bytes recieved.
data[number_of_bytes_received] = 0; // add a 0 terminator to the char array
}
bool result = strcmp (data, "whatever");
// strcmp returns 0; if inputs match.
// http://en.cppreference.com/w/c/string/byte/strcmp
if (result == 0)
{
Serial.println("data matches whatever");
}
else
{
Serial.println("data does not match whatever");
}
loop()
和 setup()
一起使用 Arduino 定义的serialEvent()
回调。
我曾经构建过一个处理消息接收的小型库,但从没来得及开源它。
该库接收以 \n 结尾的行,表示命令和任意有效负载,由空格分隔。
您可以轻松地调整它以使用自己的协议。
首先,是一个名为 SerialReciever.h 的库:#ifndef __SERIAL_RECEIVER_H__
#define __SERIAL_RECEIVER_H__
class IncomingCommand {
private:
static boolean hasPayload;
public:
static String command;
static String payload;
static boolean isReady;
static void reset() {
isReady = false;
hasPayload = false;
command = "";
payload = "";
}
static boolean append(char c) {
if (c == '\n') {
isReady = true;
return true;
}
if (c == ' ' && !hasPayload) {
hasPayload = true;
return false;
}
if (hasPayload)
payload += c;
else
command += c;
return false;
}
};
boolean IncomingCommand::isReady = false;
boolean IncomingCommand::hasPayload = false;
String IncomingCommand::command = false;
String IncomingCommand::payload = false;
#endif // #ifndef __SERIAL_RECEIVER_H__
要使用它,在您的项目中执行以下操作:
#include <SerialReceiver.h>
void setup() {
Serial.begin(115200);
IncomingCommand::reset();
}
void serialEvent() {
while (Serial.available()) {
char inChar = (char)Serial.read();
if (IncomingCommand::append(inChar))
return;
}
}
使用接收到的命令:
void loop() {
if (!IncomingCommand::isReady) {
delay(10);
return;
}
executeCommand(IncomingCommand::command, IncomingCommand::payload); // I use registry pattern to handle commands, but you are free to do whatever suits your project better.
IncomingCommand::reset();
int read_line(char* buffer, int bufsize)
{
for (int index = 0; index < bufsize; index++) {
// Wait until characters are available
while (Serial.available() == 0) {
}
char ch = Serial.read(); // read next character
Serial.print(ch); // echo it back: useful with the serial monitor (optional)
if (ch == '\n') {
buffer[index] = 0; // end of line reached: null terminate string
return index; // success: return length of string (zero if string is empty)
}
buffer[index] = ch; // Append character to buffer
}
// Reached end of buffer, but have not seen the end-of-line yet.
// Discard the rest of the line (safer than returning a partial line).
char ch;
do {
// Wait until characters are available
while (Serial.available() == 0) {
}
ch = Serial.read(); // read next character (and discard it)
Serial.print(ch); // echo it back
} while (ch != '\n');
buffer[0] = 0; // set buffer to empty string even though it should not be used
return -1; // error: return negative one to indicate the input was too long
}
const int LED_PIN = 13;
const int LINE_BUFFER_SIZE = 80; // max line length is one less than this
void setup() {
pinMode(LED_PIN, OUTPUT);
Serial.begin(9600);
}
void loop() {
Serial.print("> ");
// Read command
char line[LINE_BUFFER_SIZE];
if (read_line(line, sizeof(line)) < 0) {
Serial.println("Error: line too long");
return; // skip command processing and try again on next iteration of loop
}
// Process command
if (strcmp(line, "off") == 0) {
digitalWrite(LED_PIN, LOW);
} else if (strcmp(line, "on") == 0) {
digitalWrite(LED_PIN, HIGH);
} else if (strcmp(line, "") == 0) {
// Empty line: no command
} else {
Serial.print("Error: unknown command: \"");
Serial.print(line);
Serial.println("\" (available commands: \"off\", \"on\")");
}
}
String content = "";
char character;
if(Serial.available() >0){
//reset this variable!
content = "";
//make string from chars
while(Serial.available()>0) {
character = Serial.read();
content.concat(character);
}
//send back
Serial.print("#");
Serial.print(content);
Serial.print("#");
Serial.flush();
}
String getMessage()
{
String msg=""; //the message starts empty
byte ch; // the character that you use to construct the Message
byte d='#';// the separating symbol
if(Serial.available())// checks if there is a new message;
{
while(Serial.available() && Serial.peek()!=d)// while the message did not finish
{
ch=Serial.read();// get the character
msg+=(char)ch;//add the character to the message
delay(1);//wait for the next character
}
ch=Serial.read();// pop the '#' from the buffer
if(ch==d) // id finished
return msg;
else
return "NA";
}
else
return "NA"; // return "NA" if no message;
}
String string = "";
char ch; // Where to store the character read
void setup() {
Serial.begin(9600);
Serial.write("Power On");
}
boolean Comp(String par) {
while (Serial.available() > 0) // Don't read unless
// there you know there is data
{
ch = Serial.read(); // Read a character
string += ch; // Add it
}
if (par == string) {
string = "";
return(true);
}
else {
//dont reset string
return(false);
}
}
void loop()
{
if (Comp("m1 on")) {
Serial.write("Motor 1 -> Online\n");
}
if (Comp("m1 off")) {
Serial.write("Motor 1 -> Offline\n");
}
}