HTTP Post data from Arduino uno using WiFi

Question

Please help me to post data from arduino uno to a webpage using wifi(ESP-01) module. I try with AT commands it didn't give the response from my webpage

#include <SoftwareSerial.h>
#include <ArduinoJson.h>
#define DEBUG true

#define RX 10
#define TX 11
String WIFI_SSID = "*****";       // Your WiFi ssid
String PASSWORD = "*****";         // Password
//String DEVICE_SECRET_KEY  = "**";

//String PATH = "/v1/events";
//String PORT = "8000";
//String HOST = "http://10.**.***.66:8000/data";

String HOST = "10.**.240.**";
String PATH = "/data";
String PORT = "8000";

String response;
int countTrueCommand;
int countTimeCommand;
boolean found = false;

SoftwareSerial esp8266(RX, TX);
StaticJsonBuffer<200> jsonBuffer;
JsonObject& root = jsonBuffer.createObject();

void setup()
{
  Serial.begin(115200);
  esp8266.begin(115200);
  esp8266.println("AT");
  Serial.println(esp8266.read());
  sendCommandToESP8266("AT", 5, "OK");
   sendCommandToESP8266("AT+CWMODE=3", 5, "OK");
  sendCommandToESP8266("AT+CWJAP=\"" + WIFI_SSID + "\",\"" + PASSWORD + "\"", 20, "OK");
}

void loop()
{
  root["key"] =  "sdfsdfsd";
  String key;
  root.printTo(key);
  String postRequest =   "POST " + PATH  + " HTTP/1.1\r\n" +
                         "Host: " + HOST + "\r\n" +
                         "Accept: *" + "/" + "*\r\n" +
                         "Content-Length: " + key.length() + "\r\n" +
                         "Content-Type: application/json\r\n"
                         "\r\n" + key;
  Serial.print("pst:" + postRequest);
  sendCommandToESP8266("AT+CIPMUX=1", 5, "OK");
  sendCommandToESP8266("AT+CIPSTART=0,\"TCP\",\"" + HOST + "\"," + PORT, 15, "OK");
  String cipSend = "AT+CIPSEND=0," + String(postRequest.length());//GET /test.php?Data=2\r\nHost:192.168.1.13\r\n\r\n
  sendCommandToESP8266(cipSend, 4, ">");
  sendData(postRequest);

  while (esp8266.available())
  {
    if (esp8266.find("+IPD,"))
    {
//      String msg;
      esp8266.find("?");
//      msg = esp8266.readStringUntil(' ');
      response = esp8266.readStringUntil(' ');
      Serial.print(response);
      Serial.println();
    }
  }
  printResponse;



  //  sendCommandToESP8266("AT+CIPCLOSE=0", 5, "OK");
}

void sendCommandToESP8266(String command, int maxTime, char readReplay[]) {
  Serial.print(countTrueCommand);
  Serial.print(". at command => ");
  Serial.print(command);
  Serial.print(" ");
  while (countTimeCommand < (maxTime * 1))
  {
    esp8266.println(command);
    if (esp8266.find(readReplay))
    {
      found = true;
      break;
    }

    countTimeCommand++;
  }

  if (found == true)
  {
    Serial.println("Success");
    countTrueCommand++;
    countTimeCommand = 0;
  }

  if (found == false)
  {
    Serial.println("Fail");
    countTrueCommand = 0;
    countTimeCommand = 0;
  }

  found = false;
}

void sendData(String postRequest) {
  Serial.println(postRequest);
  Serial.println();
  esp8266.println(postRequest);
  delay(15000);
  countTrueCommand++;
}

void printResponse() {
  while (esp8266.available()) {
    Serial.println();
    Serial.println(esp8266.readStringUntil('\n'));
  }
}

Please help me to get the response from the webpage using this code.

Answer 1

Step 1) Upload software serial from example and send AT, you should get reply as AT OK if your connections are correct. Step 2) Once your connections are correct and if you are uploading the given code then make sure you put your SSID, password, and Server IP which would be the three Strings: HOST, PATH and PORT.

You could alternatively check your server first by sending it a GET or POST using your browser or another software for testing API's(I personally use POSTMAN).

Proceed further once you perform these checks.