sending data in httpclient.Post() crashes esp32

[shehrozeee]

this code is probably missing variable declarations

Code: Select all

String server_address;

bool is_config = false;

const byte interruptPin = 27;
volatile int interruptCounter = 0;
int numberOfInterrupts = 0;
 
portMUX_TYPE mux = portMUX_INITIALIZER_UNLOCKED;
 
void IRAM_ATTR handleInterrupt() {
  static unsigned long last_interrupt_time = 0;
  unsigned long interrupt_time = millis();
  portENTER_CRITICAL_ISR(&mux);
  if (interrupt_time - last_interrupt_time > 10)
  {
    interruptCounter++;
  }
  portEXIT_CRITICAL_ISR(&mux);
  last_interrupt_time = interrupt_time;
  
}


void setup_counter()
{
  is_config = false;
  Serial.begin(115200);
  Serial.println("Monitoring interrupts: ");
  pinMode(interruptPin, INPUT_PULLUP);
  pinMode(2, OUTPUT);
  attachInterrupt(digitalPinToInterrupt(interruptPin), handleInterrupt, FALLING);
  Serial.println("SSID:|"+(ssid)+"|");
  Serial.println("PASS:|"+(pass)+"|");
  
  
  WiFi.begin(string2char(ssid),string2char(pass)); 
 
  while (WiFi.status() != WL_CONNECTED) { //Check for the connection
    delay(500);
    Serial.println("Connecting..");
  }
  
  void loop() 
{

  if(is_config)
  return;
    
  //if(interruptCounter>0)
  {
  
      portENTER_CRITICAL(&mux);
      numberOfInterrupts = interruptCounter;
      interruptCounter = 0;
      portEXIT_CRITICAL(&mux);
            if(numberOfInterrupts%2 == 0)
        digitalWrite(2,HIGH);
      else
        digitalWrite(2,LOW); 
      Serial.print("An interrupt has occurred. Total: ");
      Serial.println(numberOfInterrupts); 
      HTTPClient http;
      http.begin(server_address+":9021/detected/"+device_id+"/"+numberOfInterrupts); //Specify destination for HTTP request
      http.addHeader("Content-Type", "text/plain"); //Specify content-type header   
      int httpResponseCode = http.POST(""); //Send the actual POST request
      
      Serial.println(httpResponseCode);
      if(httpResponseCode>0)
      {
        Serial.println(httpResponseCode);   //Print return code
 
      }
      else
      {
         Serial.print("Error on sending request: ");
         Serial.println(httpResponseCode);
      }
      http.end();      
      delay(5000);
  }
}
 

I am sending a light switch on/off count data to a python flask web server
The above code works perfectly fine but if I try to send anything in the post

Code: Select all

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

the esp32 crashes giving and error in WifiClient (error 104 connection reset).
to avoid this, for now I am passing the values in url but I cannot figure out why this is happening.
any idea as to why would this be happening ?

and generates this
Connected to the WiFi network with IP: 192.168.1.101
An interrupt has occurred. Total: 0
[E][WiFiClient.cpp:382] read(): 104
Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled.
Core 1 register dump:
PC : 0x400d3e0c PS : 0x00060230 A0 : 0x800d3ee3 A1 : 0x3ffb1d10
A2 : 0x00000000 A3 : 0x3ffb1d5f A4 : 0x00000001 A5 : 0x00000001
A6 : 0x00000000 A7 : 0x00000000 A8 : 0x00000000 A9 : 0x00000000
A10 : 0x00000000 A11 : 0x00000000 A12 : 0x00000050 A13 : 0x00000000
A14 : 0x00000000 A15 : 0x00000000 SAR : 0x0000000a EXCCAUSE: 0x0000001c
EXCVADDR: 0x00000008 LBEG : 0x4000c2e0 LEND : 0x4000c2f6 LCOUNT : 0xffffffff

Backtrace: 0x400d3e0c:0x3ffb1d10 0x400d3ee0:0x3ffb1d30 0x4015ed16:0x3ffb1d50 0x400daa45:0x3ffb1d80 0x400daa79:0x3ffb1da0 0x400d3359:0x3ffb1dc0 0x400d3763:0x3ffb1e50 0x400d37a3:0x3ffb1e90 0x400d37bc:0x3ffb1eb0 0x400d294a:0x3ffb1ed0 0x4014374a:0x3ffb1fa0

Rebooting...

[shehrozeee]

Turns out it was my flask server.
since I was running it in debug mode on the werkzeug wsgi server.
The connection reset issue was coming from the server.
turns out there is a well known 'Connection reset by peer' problem in python.
once I switched to a production server like waitress(windows)/gunicorn(Debian) I was no longer getting this error and everything worked fine.
But this leaves me with another question.
since my board was rebooting on the error.... how do I handle it, I mean there is no try catch in arduino. so is there something that can be done to avoid the reboot of the system. a reboot means a a few sec device downtime as it has to connect to wifi again and that can take some time.