Good night, I am opened a ngrok tunnel for my web project and I am trying to make a POST request from SIM808 module. The codes and output given below:
// Libraries / Defines
...
char httpLogin[] = "POST /api/device/login HTTP/1.1\r\nHost: subdomain.ngrok-free.app\r\nContent-Type: application/json\r\n\r\n{}";
char buffer[512];
The "{}" my request payload for testing.
...
void setup() {
mySerial.begin(9600);
Serial.begin(9600);
delay(1000);
Serial.println("[MSG] : Starting...");
while( !sim808.init() ) Serial.println("[ERR] : SIM Module couldn't initialized.");
mySerial.println("AT&F"); // Factory reset for SIM.
delay(1000);
while(mySerial.available()) {
char c = mySerial.read();
Serial.print(c);
}
while( !sim808.join( F("internet") ) ) Serial.println("[ERR] : GPRS connection failed.");
Serial.println("[STA] : GPRS connection successful.");
Serial.print("[MSG] : IP Address is "); Serial.println(sim808.getIPAddress());
sim808.detachGPS();
Serial.println("[MSG] : Logging In...");
while( !sim808.connect(TCP, "subdomain.ngrok-free.app", 80) ) {
Serial.println("[ERR] : Connection couldn't established.");
sim808.close();
delay(500);
}
Serial.println("[STA] : Connection established.");
Serial.print("[MSG] : Payload => \r\n"); Serial.println(httpLogin);
int result = sim808.send(httpLogin, sizeof(httpLogin) - 1 );
Serial.println( String(result) );
delay(5000);
int ret = sim808.recv(buffer, sizeof(buffer)-1);
if (ret <= 0) {
Serial.println("[MSG] : Fetch over...");
} else {
buffer[ret] = '\0';
Serial.print("Recv: ");
Serial.print(ret);
Serial.print(" bytes: ");
Serial.println(buffer);
}
sim808.close(); // Closes TCP/UDP connection.
sim808.disconnect();
}
Let's talk about what problem is? The problem is, I get message of "[MSG] : Fetch over..." every try and when sim808.send() works, it returns 0. It returns sent byte of data, why it is 0 ? I can't solve this and I'm working for 3 days about it. I am giving an output below:
23:35:29.323 -> OK
23:35:30.975 -> [STA] : GPRS connection successful.
23:35:31.008 -> [MSG] : IP Address is 100.**.***.**
23:35:31.040 -> [MSG] : Logging In...
23:35:34.689 -> [STA] : Connection established.
23:35:34.722 -> [MSG] : Payload =>
23:35:34.722 -> POST /api/device/login HTTP/1.1
23:35:34.755 -> Host: subdomain.ngrok-free.app
23:35:34.822 -> Content-Type: application/json
23:35:34.855 ->
23:35:34.855 -> {}
23:35:54.060 -> 0
23:36:04.104 -> [MSG] : Fetch over...
23:36:05.662 -> AT+CIPSHUT
23:36:05.662 -> SHUT OK
Lastly, the ngrok panel :
ngrok
(Ctrl+C to quit)
Try the ngrok Kubernetes Ingress Controller: https://ngrok.com/s/k8s-ingress
Session Status online
Account ***** ****** (Plan: Free)
Version 3.3.4
Region Europe (eu)
Latency -
Web Interface http://127.0.0.1:4040
Forwarding https://subdomain.ngrok-free.app -> http://127.0.0.1:8000
Connections ttl opn rt1 rt5 p50 p90
0 0 0.00 0.00 0.00 0.00
Lastly, I've tried these two things:
Serial.println("[STA] : Connection established.");
int size = sizeof(httpLogin) - 1; // 210
int sizestr = String(httpLogin).length(); // 0
Serial.print("[MSG] : Size / Payload => " + String(size) + " / " + String(sizestr) + "\r\n"); Serial.println(httpLogin);
Output: [MSG] : Size / Payload => 0 / 210 ...
After this test, I've tried to send two of them.
int result = sim808.send( httpLogin, size /* 210 */ );
Output:
13:00:49.517 -> 0
13:00:54.551 -> [MSG] : Fetch over...
int result = sim808.send( httpLogin, sizestr /* 0 */);
Output:
13:02:32.586 -> 0
13:02:35.908 -> [MSG] : Received 93 bytes =>
13:02:35.908 -> HTTP/1.1 400 Bad Request
13:02:35.954 -> Content-Length: 11
13:02:35.990 -> Connection: close
13:02:36.031 -> Content-Type: text/plain
13:02:36.031 ->
13:02:36.031 ->
