I’m trying to send data from my ESP32 to a Django project deployed on my computer. However, the ESP32 seems cannot fetch the address of Django project, here are details:

My computer and ESP32 chip are connected to the same Wi-Fi network. The Django project is running on 127.0.0.1:8000, and I’m attempting to send data from the ESP32 to xxx.xxx.xxx.xxx:8000/suitcase/esp32_test (where xxx.xxx.xxx.xxx is my computer’s IP address). However, the ESP32 was unable to successfully transmit data to this address, Django local terminal didn’t show anything about ESP32’s message. I’ve tried changing the server address in the ESP32 code to 127.0.0.1:8000, but it apparently didn’t resolve the issue. What could be causing this problem and how can I troubleshoot it?

The esp32 code:

#include <HardwareSerial.h>
#include <HTTPClient.h>
#include "WiFi.h"
#define GPSRX_PIN 16
#define GPSTX_PIN 17
#define GPS_SERIAL Serial2

const String serverAddress = "xxx.xxx.xxx.xxx:8000/suitcase/esp32_test";

void initWiFi(String ssid, String password) {
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  Serial.print("***********Connecting to WiFi ..");
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print('.');
    delay(1000);
  }
  Serial.println("WiFi connected");

  Serial.println("IP address: ");
    Serial.println(WiFi.localIP()); 
    Serial.println(WiFi.RSSI()); 
}

bool HaveUsefulData(String data){
  if(data.startsWith("$GNGLL")){
    return true;
  }else{
    return false;
  }
}

String ExtractProxy(String data){
    int commaIndex = data.indexOf(',');

    if (commaIndex != -1 && data.length() > commaIndex + 13) {

      String longitude = data.substring(commaIndex + 1, commaIndex + 10);

      String latitude = data.substring(commaIndex + 14, commaIndex + 24);


      return "{'latitude': "+ latitude +", 'longitude': "+ longitude +"}";
    }else{
      return "";
    }
}

void SendProxyToServer(String proxy){

  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(serverAddress); 
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");
    Serial.println("check2");


    int httpResponseCode = http.POST(proxy);
    if (httpResponseCode > 0) {//*********where the program cannot get in **************//
      Serial.println("check3");
      Serial.print("HTTP Response code: ");
      Serial.println(httpResponseCode);
    } else {
      Serial.print("Error code: ");
      Serial.println(httpResponseCode);
    }


    http.end();
  } else {
    Serial.println("WiFi Disconnected");
  }
};

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  GPS_SERIAL.begin(115200, SERIAL_8N1, GPSTX_PIN, GPSRX_PIN);

  const String ssid     = "Redmi K70 Pro";
  const String password = "password";
  initWiFi(ssid, password);
}

void loop() {
  static String ubxData = "";
  while (GPS_SERIAL.available()) {
          char c = GPS_SERIAL.read();
          ubxData += c;
          if (c == 'n') {

              if (HaveUsefulData(ubxData)){
                
                String ProxyJSON = ExtractProxy(ubxData);

                Serial.println(ProxyJSON);

                if(ProxyJSON != ""){
                  Serial.println("check1");
                  SendProxyToServer(ProxyJSON);
                }
                
              }

              ubxData = "";
              }
  }

}

related code in views.py:

@csrf_exempt
def esp32_test(request):
    if request.method == 'POST':

        longitude = request.POST.get('longitude', '')
        latitude = request.POST.get('latitude', '')


        print("Received data from ESP32:", request.POST)


        return JsonResponse({'message': 'Data received successfully'})


    return JsonResponse({'error': 'Invalid request method'})

urls.py:

urlpatterns = [
    path("esp32_test", views.esp32_test, name="esp32_test")
]

everytime the ESP32 chip sent request to Django I will get this error on the serial monitor

{'latitude': xxxxx.xxxx, 'longitude': xxxx.xxxx}
check1
check2
Error code: -1

the “check3” print instruction cannot be triggered.

I’ve attempted to substitute my computer’s address in the ESP32 code with a test URL from Pipedream, and sent messages from the ESP32 to pipedream.com, the website successfully received the data from my ESP32, under which circumstances the serial monitor show:

{'latitude': xxxxx.xxxx, 'longitude': xxxx.xxxx}
check1
check2
check3
HTTP Response code: 200

Additionally, I tested the receiving capability of Django using the POST method in Postman with suitable body, and Django was able to receive the data and print it out as well.

I assume that this issue may have association with my network, or I cannot give the correct address of my Django project in ESP32 code, however, I cannot find out ways to solve the problem.Despite these successful tests, I’m still puzzled by the issue of why my Django project isn’t receiving data directly from the ESP32 when connected to my computer. Any advice or suggestions on how to troubleshoot this further would be greatly appreciated!