Sim7600E kc868_A4S GSM SIM Internet Is not working - 4G and 3G Enabled

[venuakil2]

Hi, I am Sim7600E kc868_A4S Model to call website URL after Internet activation. 

SIM Yellow Light is blinking. 

SIM call and SMS are working. But, Internet is not working. I have changed SIM Provider APN details


#include <HardwareSerial.h>
// Define SIM7600 UART
#define MODEM_RX 13   // Connect to SIM7600 TX
#define MODEM_TX 15   // Connect to SIM7600 RX
HardwareSerial sim7600(1);  // Use UART1
const char* APN = "du";    // Set your network APN
const char* USER = "";     // Usually blank
const char* PASS = "";     // Usually blank
void setup() {
  Serial.begin(115200);           // USB serial
  sim7600.begin(115200, SERIAL_8N1, MODEM_RX, MODEM_TX); // UART1
  delay(5000);  // Give time to power up
  Serial.println("Initializing SIM7600...");
  // Disable echo for clean output
  sendATCommand("ATE0", "OK", 1000);
  // Basic check
  if (!retryCommand("AT", "OK", 2000, 3)) {
    Serial.println("SIM7600 not responding!");
    while (1);
  }
  // SIM card check
  if (!sendATCommand("AT+CPIN?", "READY", 2000)) {
    Serial.println("SIM Card not ready!");
    while (1);
  }
  // Set LTE-only mode
  sendATCommand("AT+CNMP=38", "OK", 3000);
  sendATCommand("AT+CMNB=1", "OK", 3000);
  // Set APN
  String apnCmd = "AT+CGDCONT=1,\"IP\",\"" + String(APN) + "\"";
  sendATCommand(apnCmd.c_str(), "OK", 3000);
  // Attach to network
  if (!sendATCommand("AT+CGATT=1", "OK", 10000)) {
    Serial.println("Failed to attach to network!");
    while (1);
  }
  // Activate PDP
  if (!sendATCommand("AT+CGACT=1,1", "OK", 10000)) {
    Serial.println("Failed to activate PDP!");
    while (1);
  }
  // Show IP
  printIPAddress();
}
void loop() {
  // Optional: monitor SIM7600 data or implement HTTP
}
// ========== AT COMMAND HELPERS ==========
bool sendATCommand(const char* cmd, const char* expected, uint32_t timeout) {
  sim7600.flush();
  sim7600.println(cmd);
  Serial.print(">> "); Serial.println(cmd);
  uint32_t start = millis();
  String response;
  while (millis() - start < timeout) {
    while (sim7600.available()) {
      char c = sim7600.read();
      Serial.write©;
      response += c;
      if (response.indexOf(expected) != -1) {
        return true;
      }
    }
  }
  Serial.println("\n!! Timeout or Unexpected response:");
  Serial.println(response);
  return false;
}
bool retryCommand(const char* cmd, const char* expected, uint32_t timeout, int retries) {
  for (int i = 0; i < retries; i++) {
    if (sendATCommand(cmd, expected, timeout)) return true;
    delay(1000);
  }
  return false;
}
void printIPAddress() {
  Serial.println("Checking IP with AT+CGPADDR=1...");
  sim7600.println("AT+CGPADDR=1");
  delay(1000);
  String response;
  while (sim7600.available()) {
    char c = sim7600.read();
    Serial.write©;
    response += c;
  }
  int ipStart = response.indexOf(",\"") + 2;
  int ipEnd = response.indexOf("\"", ipStart);
  if (ipStart > 1 && ipEnd > ipStart) {
    String ip = response.substring(ipStart, ipEnd);
    Serial.print("Assigned IP: ");
    Serial.println(ip);
  } else {
    Serial.println("No IP Address Assigned");
  }
}

OutPut  
13:57:40.249 -> >> AT
13:57:42.215 -> !! Timeout or Unexpected response:
13:57:49.212 -> SIM7600 not responding!


Note : SIM calling is working 
Note 2: SIM SMS are working.
Only Internet is not activated. I have to call website URL after Internet connected. 


   

[admin]

we have demo code for SMS and CALL. SIM7600 support MQTT connection. what function you want to use? do you want use SIM7600 to visite internet webpage? or ?

[venuakil2]

Hi , Thank you for Reply.
I have to Send call API URL with Post JSON Data  and Connect WiFiClient socket for Heartbeat and communication purpose.



HTTPClient http;
WiFiClient client;

client.connect(serverIP, 80);



void sendTelemetry() {
  HTTPClient http;

  DynamicJsonDocument doc(512);

  doc["serialNumber"] = device_serial_number;  // alarmSystem.config.deviceID;
  doc["temperature"] = alarmSystem.sensors.temperature;
  doc["humidity"] = alarmSystem.sensors.humidity;
  doc["current_mA"] = alarmSystem.sensors.current_mA;
  doc["status"] = static_cast<int>(alarmSystem.currentState);
  doc["doorOpen"] = alarmSystem.sensors.doorOpen ? 1 : 0;
  doc["waterLeakage"] = alarmSystem.sensors.waterLeak ? 1 : 0;
  doc["acPowerFailure"] = alarmSystem.sensors.powerFail ? 1 : 0;
  doc["fire"] = alarmSystem.sensors.fire ? 1 : 0;
  doc["temperature_alarm"] = 0;

  if (alarmSystem.sensors.temperature > alarmSystem.config.tempThreshold) {
    doc["temperature_alarm"] = 1;
  }

  String payload;
  serializeJson(doc, payload);

  sensorData=payload;



  http.begin(serverURL + "/alarm_device_status");
  http.addHeader("Content-Type", "application/json");
  int httpCode = http.POST(payload);


  //Serial.println(serverURL);

  if (httpCode > 0) {
    Serial.println("HTTP Response: " + String(httpCode));
  } else {
    Serial.println("HTTP Error: " + String(httpCode));
  }
  http.end();
}

[venuakil2]

Can I use Configure PPP connection?

[admin]

i am not tested with pppoe connection, only have used mqtt. if esp32 work as a router with sim7600e, i think it's not very suitable.