用c写一个串口监听的例子
时间: 2023-03-24 22:01:40 浏览: 56
好的,以下是一个用C语言编写的简单的监听键盘输入的示例:
```
#include <stdio.h>
#include <conio.h>
int main() {
char ch;
printf("请输入一个字符:");
ch = getch(); // 监听键盘输入
printf("\n您输入的字符是:%c", ch);
return 0;
}
```
这个程序会在屏幕上显示提示信息,等待用户输入一个字符。然后使用 `getch()` 函数监听键盘输入,并将用户输入的字符存储到 `ch` 变量中。最后程序将用户输入的字符打印到屏幕上。
相关问题
epoll 读串口例子
以下是一个使用 epoll 读取串口数据的示例代码,供您参考:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
#include <sys/epoll.h>
#define MAX_EVENTS 10
#define BUF_SIZE 256
int set_interface_attribs(int fd, int speed) {
struct termios tty;
memset(&tty, 0, sizeof(tty));
if (tcgetattr(fd, &tty) != 0) {
printf("Error %d from tcgetattr\n", errno);
return -1;
}
cfsetospeed(&tty, (speed_t)speed);
cfsetispeed(&tty, (speed_t)speed);
tty.c_cflag |= (CLOCAL | CREAD); // ignore modem controls
tty.c_cflag &= ~CSIZE;
tty.c_cflag |= CS8; // 8-bit characters
tty.c_cflag &= ~PARENB; // no parity bit
tty.c_cflag &= ~CSTOPB; // only need 1 stop bit
tty.c_cflag &= ~CRTSCTS; // no hardware flowcontrol
// setup for non-canonical mode
tty.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
tty.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
tty.c_oflag &= ~OPOST;
// fetch bytes as they become available
tty.c_cc[VMIN] = 1;
tty.c_cc[VTIME] = 1;
if (tcsetattr(fd, TCSANOW, &tty) != 0) {
printf("Error %d from tcsetattr\n", errno);
return -1;
}
return 0;
}
int set_blocking(int fd, int should_block) {
struct termios tty;
memset(&tty, 0, sizeof(tty));
if (tcgetattr(fd, &tty) != 0) {
printf("Error %d from tggetattr\n", errno);
return -1;
}
tty.c_cc[VMIN] = should_block ? 1 : 0;
tty.c_cc[VTIME] = 5; // 0.5 seconds read timeout
if (tcsetattr(fd, TCSANOW, &tty) != 0) {
printf("Error %d setting term attributes\n", errno);
return -1;
}
return 0;
}
int main() {
int fd = open("/dev/ttyUSB0", O_RDWR | O_NOCTTY | O_SYNC);
if (fd < 0) {
printf("Error %d opening serial port\n", errno);
return -1;
}
if (set_interface_attribs(fd, B9600) < 0) {
printf("Error setting serial port attributes\n");
return -1;
}
if (set_blocking(fd, 0) < 0) {
printf("Error setting serial port blocking mode\n");
return -1;
}
int efd = epoll_create1(0);
if (efd == -1) {
printf("Error %d creating epoll instance\n", errno);
return -1;
}
struct epoll_event ev, events[MAX_EVENTS];
ev.events = EPOLLIN;
ev.data.fd = fd;
if (epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ev) == -1) {
printf("Error %d adding file descriptor to epoll instance\n", errno);
return -1;
}
char buf[BUF_SIZE];
while (1) {
int n = epoll_wait(efd, events, MAX_EVENTS, -1);
if (n == -1) {
printf("Error %d from epoll_wait\n", errno);
break;
}
for (int i = 0; i < n; i++) {
if (events[i].events & EPOLLIN) {
int len = read(fd, buf, BUF_SIZE);
if (len > 0) {
buf[len] = 0;
printf("Received %d bytes: %s\n", len, buf);
}
}
}
}
close(fd);
close(efd);
return 0;
}
```
此示例代码使用 epoll 监听串口的 EPOLLIN 事件,当有数据可读时,使用非阻塞读取方式从串口读取数据。在读取到数据后,将其打印到控制台上。同时,该示例代码也设置了串口的基本参数,以确保能够正确地读取串口数据。
写一个连接wifi,连接tcp服务,将获取到的数据合并输出到串口的Arduino实例
以下是一个基本的连接WiFi并通过TCP连接将数据输出到串口的Arduino示例:
```C++
#include <SPI.h>
#include <WiFiNINA.h>
#include <WiFiClient.h>
// replace with your network credentials
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
// replace with your server IP address
IPAddress serverIP(192, 168, 1, 100);
int serverPort = 8888;
WiFiClient client;
void setup() {
Serial.begin(9600);
while (!Serial);
// attempt to connect to WiFi network
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void loop() {
if (!client.connected()) {
Serial.println("Connecting to server...");
if (client.connect(serverIP, serverPort)) {
Serial.println("Connected to server");
client.println("Hello, world!");
} else {
Serial.println("Connection failed");
}
}
if (client.available()) {
char c = client.read();
Serial.print(c);
}
}
```
这个例子假设你已经存在一个Wi-Fi网络,并且你知道你的网络的SSID和密码。它还假设你有一个TCP服务器在IP地址192.168.1.100上监听端口8888。
在setup()函数中,我们连接到Wi-Fi网络并打印出我们的IP地址。在loop()函数中,我们检查是否连接到服务器。如果没有连接,我们试图连接到服务器。如果连接成功,我们发送一条消息“Hello, world!”。如果服务器有数据可用,我们将数据读入并将其打印到串口。
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