我正在使用 ESP8266 板更新我用 PHP 构建的网站中的温度和湿度传感器数据。对于数据库，我使用的是 MySQL。
但是当我运行代码时，我得到 -1 作为 HTTP POST 请求响应。 arduino代码如下：
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <Arduino_JSON.h>
#include <WiFiClient.h>
#include "DHT.h"
//========================================
//======================================== DHT sensor settings (DHT11).
#define DHTPIN D1 //--> Defines the Digital Pin connected to the DHT11 sensor.
#define DHTTYPE DHT11 //--> Defines the type of DHT sensor used. Here used is the DHT11 sensor.
DHT dht11_sensor(DHTPIN, DHTTYPE); //--> Initialize DHT sensor.
//========================================
// Defines the Digital Pin of the "On Board LED".
#define ON_Board_LED LED_BUILTIN
// Defines GPIO 13 as LED_1.
#define LED_01 D2
// Defines GPIO 12 as LED_2.
#define LED_02 D4
//======================================== SSID and Password of your WiFi router.
const char* ssid = "Prime@Flash Net";
const char* password = "prime.2022";
//========================================
//======================================== Variables for HTTP POST request data.
String postData = ""; //--> Variables sent for HTTP POST request data.
String payload = ""; //--> Variable for receiving response from HTTP POST.
//========================================
//======================================== Variables for DHT11 sensor data.
float send_Temp;
int send_Humd;
String send_Status_Read_DHT11 = "";
//========================================
//________________________________________________________________________________ Subroutine to control LEDs after successfully fetching data from database.
void control_LEDs() {
Serial.println();
Serial.println("---------------control_LEDs()");
JSONVar myObject = JSON.parse(payload);
// JSON.typeof(jsonVar) can be used to get the type of the var
if (JSON.typeof(myObject) == "undefined") {
Serial.println("Parsing input failed!");
Serial.println("---------------");
return;
}
if (myObject.hasOwnProperty("LED_01")) {
Serial.print("myObject[\"LED_01\"] = ");
Serial.println(myObject["LED_01"]);
}
if (myObject.hasOwnProperty("LED_02")) {
Serial.print("myObject[\"LED_02\"] = ");
Serial.println(myObject["LED_02"]);
}
if(strcmp(myObject["LED_01"], "ON") == 0) {digitalWrite(LED_01, HIGH); Serial.println("LED 01 ON"); }
if(strcmp(myObject["LED_01"], "OFF") == 0) {digitalWrite(LED_01, LOW); Serial.println("LED 01 OFF");}
if(strcmp(myObject["LED_02"], "ON") == 0) {digitalWrite(LED_02, HIGH); Serial.println("LED 02 ON"); }
if(strcmp(myObject["LED_02"], "OFF") == 0) {digitalWrite(LED_02, LOW); Serial.println("LED 02 OFF");}
Serial.println("---------------");
}
//________________________________________________________________________________
// ________________________________________________________________________________ Subroutine to read and get data from the DHT11 sensor.
void get_DHT11_sensor_data() {
Serial.println();
Serial.println("-------------get_DHT11_sensor_data()");
// Reading temperature or humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
// Read temperature as Celsius (the default)
send_Temp = dht11_sensor.readTemperature();
// Read Humidity
send_Humd = dht11_sensor.readHumidity();
// Read temperature as Fahrenheit (isFahrenheit = true)
// float ft = dht11_sensor.readTemperature(true);
// Check if any reads failed.
if (isnan(send_Temp) || isnan(send_Humd)) {
Serial.println("Failed to read from DHT sensor!");
send_Temp = 0.00;
send_Humd = 0;
send_Status_Read_DHT11 = "FAILED";
} else {
send_Status_Read_DHT11 = "SUCCEED";
}
Serial.printf("Temperature : %.2f °C\n", send_Temp);
Serial.printf("Humidity : %d %%\n", send_Humd);
Serial.printf("Status Read DHT11 Sensor : %s\n", send_Status_Read_DHT11);
Serial.println("-------------");
}
// ________________________________________________________________________________
//________________________________________________________________________________ VOID SETUP()
void setup() {
// put your setup code here, to run once:
Serial.begin(115200); //--> Initialize serial communications with the PC.
pinMode(ON_Board_LED,OUTPUT); //--> On Board LED port Direction output.
pinMode(LED_01,OUTPUT); //--> LED_01 port Direction output.
pinMode(LED_02,OUTPUT); //--> LED_02 port Direction output.
digitalWrite(ON_Board_LED, HIGH); //--> Turn on Led On Board.
digitalWrite(LED_01, HIGH); //--> Turn on LED_01.
digitalWrite(LED_02, HIGH); //--> Turn on LED_02.
delay(2000);
digitalWrite(ON_Board_LED, LOW); //--> Turn off Led On Board.
digitalWrite(LED_01, LOW); //--> Turn off Led LED_01.
digitalWrite(LED_02, LOW); //--> Turn off Led LED_02.
//---------------------------------------- Make WiFi on ESP32 in "STA/Station" mode and start connecting to WiFi Router/Hotspot.
WiFi.mode(WIFI_STA);
WiFi.begin(ssid, password);
//----------------------------------------
Serial.println();
Serial.println("-------------");
Serial.print("Connecting");
//---------------------------------------- The process of connecting the WiFi on the ESP32 to the WiFi Router/Hotspot.
// The process timeout of connecting ESP32 with WiFi Hotspot / WiFi Router is 20 seconds.
// If within 20 seconds the ESP32 has not been successfully connected to WiFi, the ESP32 will restart.
// I made this condition because on my ESP32, there are times when it seems like it can't connect to WiFi, so it needs to be restarted to be able to connect to WiFi.
int connecting_process_timed_out = 20; //--> 20 = 20 seconds.
connecting_process_timed_out = connecting_process_timed_out * 2;
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
//........................................ Make the On Board Flashing LED on the process of connecting to the wifi router.
digitalWrite(ON_Board_LED, HIGH);
delay(250);
digitalWrite(ON_Board_LED, LOW);
delay(250);
//........................................
//........................................ Countdown "connecting_process_timed_out".
if(connecting_process_timed_out > 0) connecting_process_timed_out--;
if(connecting_process_timed_out == 0) {
delay(1000);
ESP.restart();
}
//........................................
}
//----------------------------------------
digitalWrite(ON_Board_LED, LOW); //--> Turn off the On Board LED when it is connected to the wifi router.
//---------------------------------------- If successfully connected to the wifi router, the IP Address that will be visited is displayed in the serial monitor
Serial.println();
Serial.print("Successfully connected to : ");
Serial.println(ssid);
//Serial.print("IP address: ");
//Serial.println(WiFi.localIP());
Serial.println("-------------");
//----------------------------------------
// Setting up the DHT sensor (DHT11).
dht11_sensor.begin();
delay(2000);
}
//________________________________________________________________________________
//________________________________________________________________________________ VOID LOOP()
void loop() {
// put your main code here, to run repeatedly
//---------------------------------------- Check WiFi connection status.
if(WiFi.status()== WL_CONNECTED) {
WiFiClient client;
HTTPClient http; //--> Declare object of class HTTPClient.
int httpCode; //--> Variables for HTTP return code.
//........................................ Process to get LEDs data from database to control LEDs.
postData = "id=esp32_01";
payload = "";
digitalWrite(ON_Board_LED, HIGH);
Serial.println();
Serial.println("---------------getdata.php");
// In this project I use local server or localhost with XAMPP application.
// So make sure all PHP files are "placed" or "saved" or "run" in the "htdocs" folder.
// I suggest that you create a new folder for this project in the "htdocs" folder.
// The "htdocs" folder is in the "xampp" installation folder.
// The order of the folders I recommend:
// xampp\htdocs\your_project_folder_name\phpfile.php
//
// ESP32 accesses the data bases at this line of code:
// http.begin("http://REPLACE_WITH_YOUR_COMPUTER_IP_ADDRESS/REPLACE_WITH_PROJECT_FOLDER_NAME_IN_htdocs_FOLDER/getdata.php");
// REPLACE_WITH_YOUR_COMPUTER_IP_ADDRESS = there are many ways to see the IP address, you can google it.
// But make sure that the IP address used is "IPv4 address".
// Example : http.begin("http://192.168.0.0/ESP32_MySQL_Database/Final/getdata.php");
http.begin(client, "http://127.0.0.1/Project/getdata.php"); //--> Specify request destination
http.addHeader("Content-Type", "application/x-www-form-urlencoded"); //--> Specify content-type header
httpCode = http.POST(postData); //--> Send the request
payload = http.getString(); //--> Get the response payload
Serial.print("httpCode : ");
Serial.println(httpCode); //--> Print HTTP return code
Serial.print("payload : ");
Serial.println(payload); //--> Print request response payload
http.end(); //--> Close connection
Serial.println("---------------");
digitalWrite(ON_Board_LED, LOW);
//........................................
// Calls the control_LEDs() subroutine.
control_LEDs();
delay(1000);
// Calls the get_DHT11_sensor_data() subroutine.
get_DHT11_sensor_data();
//........................................ The process of sending the DHT11 sensor data and the state of the LEDs to the database.
String LED_01_State = "";
String LED_02_State = "";
if (digitalRead(LED_01) == 1) LED_01_State = "ON";
if (digitalRead(LED_01) == 0) LED_01_State = "OFF";
if (digitalRead(LED_02) == 1) LED_02_State = "ON";
if (digitalRead(LED_02) == 0) LED_02_State = "OFF";
postData = "id=esp32_01";
postData += "&temperature=" + String(send_Temp);
postData += "&humidity=" + String(send_Humd);
postData += "&status_read_sensor_dht11=" + send_Status_Read_DHT11;
postData += "&led_01=" + LED_01_State;
postData += "&led_02=" + LED_02_State;
payload = "";
digitalWrite(ON_Board_LED, HIGH);
Serial.println();
Serial.println("---------------updateDHT11data_and_recordtable.php");
// Example : http.begin("http://192.168.0.0/ESP32_MySQL_Database/Final/updateDHT11data_and_recordtable.php");
http.begin(client, "http://127.0.0.1/Project/updateDHT11data_and_recordtable.php"); //--> Specify request destination
http.addHeader("Content-Type", "application/x-www-form-urlencoded"); //--> Specify content-type header
httpCode = http.POST(postData); //--> Send the request
payload = http.getString(); //--> Get the response payload
Serial.print("httpCode : ");
Serial.println(httpCode); //--> Print HTTP return code
Serial.print("payload : ");
Serial.println(payload); //--> Print request response payload
http.end(); //Close connection
Serial.println("---------------");
digitalWrite(ON_Board_LED, LOW);
//........................................
delay(4000);
}
//----------------------------------------
}
输出：
---------------updateDHT11data_and_recordtable.php
httpCode : -1
payload :
---------------
我试图更改与其他网站的链接，但我得到了相同的回复。非常感谢任何帮助！
您发布的代码使用
127.0.0.1http.begin(client, "http://127.0.0.1/Project/getdata.php"); //--> Specify request destination
127.0.0.1localhost127.0.0.1localhost您需要在您尝试访问的服务器上找到正确的 IP 地址或网络接口名称，并使用它来代替
127.0.0.1