Making a http POST request using Arduino

user_443500 0
Viewed 59125

I am trying to post information to an API on a web project that I have created and hosted. I am not sure what the exact format is for the HTTP POST request. Every time I try I get HTTP 400 errors with the message that there is "an invalid verb".

Sample Code:

byte server[] = {"our IP"}
..
..

client(server, 80)
..
..
client.println("POST /Api/AddParking/3");

It connects to the IP address supplied without any problems, but all I get back in the above mentioned HTTP error code 400. I am not sure if I was supposed to include a HTTP version after my POST or and Content-Length or any other information.

arduino post http
4 Answers

Another option is using the HTTPClient.h (for the arduino IDE on adafruit's ESP32 feather), which handles https with no effort it seems. I'm including JSON payload also and can successfully send an IFTTT webhook.

  HTTPClient http;
  String url="https://<IPaddress>/testurl";
  String jsondata=(<properly escaped json data here>);

  http.begin(url); 
  http.addHeader("Content-Type", "Content-Type: application/json"); 

  int httpResponseCode = http.POST(jsondata); //Send the actual POST request

  if(httpResponseCode>0){
    String response = http.getString();  //Get the response to the request
    Serial.println(httpResponseCode);   //Print return code
    Serial.println(response);           //Print request answer
  } else {
    Serial.print("Error on sending POST: ");
    Serial.println(httpResponseCode);

    http.end();

 }
user_102468040

Requests can be sent like that too

 // Check if we are Connected.
 if(WiFi.status()== WL_CONNECTED){   //Check WiFi connection status
    HTTPClient http;    //Declare object of class HTTPClient

    http.begin("http://useotools.com/");      //Specify request destination
    http.addHeader("Content-Type", "application/x-www-form-urlencoded", false, true);
    int httpCode = http.POST("type=get_desire_data&"); //Send the request

    Serial.println(httpCode);   //Print HTTP return code
    http.writeToStream(&Serial);  // Print the response body

}
user_8890300
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