树莓派 dht11读取数据并上传阿里云端的c语言代码

好的,我可以为您提供一个使用C语言在树莓派上读取DHT11传感器数据并上传到阿里云端的示例代码。以下是一个基本的实现: ```c #include <wiringPi.h> #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <string.h> #include <unistd.h> #include <MQTTPacket.h> #define DHT_PIN 7 // DHT11数据引脚连接到GPIO4 (BCM编码为7) #define HOST_NAME "your_host_name" #define PORT 1883 #define TOPIC "your_topic" #define CLIENT_ID "your_client_id" #define USER_NAME "your_user_name" #define PASSWORD "your_password" int readDHT11Data(float *temperature, float *humidity) { uint8_t laststate = HIGH; uint8_t counter = 0; uint8_t j = 0, i; float f; *temperature = *humidity = 0; pinMode(DHT_PIN, OUTPUT); digitalWrite(DHT_PIN, LOW); delay(18); digitalWrite(DHT_PIN, HIGH); delayMicroseconds(40); pinMode(DHT_PIN, INPUT); for (i = 0; i < 85; i++) { counter = 0; while (digitalRead(DHT_PIN) == laststate) { counter++; delayMicroseconds(1); if (counter == 255) break; } laststate = digitalRead(DHT_PIN); if (counter == 255) break; if ((i >= 4) && (i % 2 == 0)) { f = counter; if (j < 16) *humidity = *humidity * 2.0 + (f > 40 ? 1 : 0); else if (j < 32) *temperature = *temperature * 2.0 + (f > 40 ? 1 : 0); j++; } } if (j >= 40) { *humidity /= 10.0; *temperature /= 10.0; return 1; } else { return 0; } } int main(int argc, char** argv) { float temperature, humidity; int ret; if (wiringPiSetup() == -1) { printf("wiringPi setup error\n"); return 1; } int sock = socket(AF_INET, SOCK_STREAM, 0); struct sockaddr_in server; server.sin_family = AF_INET; server.sin_port = htons(PORT); server.sin_addr.s_addr = inet_addr(HOST_NAME); if (connect(sock, (struct sockaddr *)&server, sizeof(server)) != 0) { printf("Connect to server failed\n"); return 1; } while (1) { ret = readDHT11Data(&temperature, &humidity); if (ret) { printf("Temperature: %.1f C, Humidity: %.1f %%\n", temperature, humidity); char payload[100]; sprintf(payload, "{\"temperature\":%.1f,\"humidity\":%.1f}", temperature, humidity); MQTTString topicString = MQTTString_initializer; topicString.cstring = (char*)TOPIC; MQTTString clientId = MQTTString_initializer; clientId.cstring = (char*)CLIENT_ID; MQTTPacket_connectData data = MQTTPacket_connectData_initializer; data.clientID = clientId; data.username.cstring = (char*)USER_NAME; data.password.cstring = (char*)PASSWORD; MQTTString hostname = MQTTString_initializer; hostname.cstring = (char*)HOST_NAME; MQTTConnect(&data); MQTTSubscribe(&topicString, QOS0, NULL); MQTTPublish(&hostname, &topicString, &data, payload, strlen(payload), QOS0, 0, NULL); close(sock); sleep(60); // 每60秒读取一次数据 } else { printf("Read DHT11 data failed\n"); sleep(5); // 读取失败后等待5秒 } } return 0; } ``` 这段代码实现了以下功能: 1. 使用wiringPi库初始化树莓派GPIO。 2. 实现了读取DHT11传感器数据的函数readDHT11Data。 3. 使用socket编程连接到阿里云MQTT服务器。 4. 读取DHT11数据并通过MQTT协议上传到阿里云。 请注意,这段代码需要根据您的实际情况进行一些修改: 1. 替换HOST_NAME, PORT, TOPIC, CLIENT_ID, USER_NAME, PASSWORD等宏定义为您自己的阿里云MQTT服务器信息。 2. 确保正确设置DHT_PIN宏定义,使其与您的硬件连接相符。 3. 您可能需要安装wiringPi库和paho MQTT库来编译这段代码。 4. 根据您的需求调整数据上传的频率。