Raspberry pi Pico W is halting at random whilst making consecutive http get requests

Question

I am developing a project using the pi pico w and I need to make get and post request to a website to report that the device is live and to send temperature data and to receive commands for now the only request I'm making is to reefdripper.ddnss.com/data which returns a random uuidv4 id. Every time I run the program my pico freezes after a random amount of requests sometimes its ten other times its 143

Also it seems to halt much quicker on average if I try to add loop1() and setup1() in the code to blink the onboard led.

I use the Arduino framework for the code

Here is my code:

#include <Arduino.h>
#include <WiFi.h>
#include "HTTPClient.h"

struct HTTPResponse
{
  String response;
  int code;
};

struct HTTPWIFI
{
  private:
    HTTPClient http;

    HTTPResponse httpGETRequest(String serverName, String uri)
    {
      String payload = "{}"; 
      http.begin(serverName+uri);
      int httpResponseCode = http.GET();
      payload = http.getString();
      http.end();
      return {payload, httpResponseCode};
    }
    
    HTTPResponse httpPOSTRequest(String serverName, String uri, String ContentType, String data)
    {
      String payload = "{}";
      http.begin(serverName+uri);
      http.addHeader("Content-Type", ContentType.c_str());
      int code = http.POST(data.c_str());
      payload = http.getString();
      http.end();
      return {payload, code};
    }
  public:
    void Setup(String ssid, String passwd)
    {
      WiFi.begin(ssid.c_str(), passwd.c_str());
    
      while(WiFi.status() != WL_CONNECTED) {
          delay(750);
      }

      http.setReuse(true);
    }

    bool isConnectedtoWifi() { return (WiFi.status() == WL_CONNECTED); }

    HTTPResponse PostRequest(String servername, String uri, String ContentType, String data)
    {
      return this->httpPOSTRequest(servername, uri, ContentType, data);
    }

    HTTPResponse GetRequest(String servername, String url)
    {
      return this->httpGETRequest(servername.c_str(), url.c_str());
    }
};

String SSID   = ""; // removed
String PASSWD = ""; // removed
String APIURL = "http://reefdripper.ddnss.org";

HTTPWIFI WifiHandler;

void setup() {
  Serial.begin(115200);
  WifiHandler.Setup(SSID, PASSWD);
}

void loop() {
  if (WifiHandler.isConnectedtoWifi())
  {
    Serial.println(WifiHandler.GetRequest(APIURL, "/data").response);
    delay(1000);
  } else {
    Serial.println("NOT connected");
  }
}

I tried the debugger for errors but none were there. I tried to find memory leaks in the source code but no luck either. I searched the internet for help most were about the _thread module in micropython

I can't switch to micropython because of how slow it is a request in c++ takes 300ms while one in python takes 2.3 seconds

Help is greatly appreciated!

Answer 1

I found a fix which is to use watchdog from the PICO SDK. With it, I can use both cores with no halting!

Documentation

Here's the working code:

#include <Arduino.h>
#include <WiFi.h>
#include "HTTPClient.h"

struct HTTPResponse
{
  String response;
  int code;
};

struct HTTPWIFI
{
  private:
    HTTPClient http;

    HTTPResponse httpGETRequest(String serverName, String uri)
    {
      String payload = "{}"; 
      http.begin(serverName+uri);
      int httpResponseCode = http.GET();
      payload = http.getString();
      http.end();
      return {payload, httpResponseCode};
    }
    
    HTTPResponse httpPOSTRequest(String serverName, String uri, String ContentType, String data)
    {
      String payload = "{}";
      http.begin(serverName+uri);
      http.addHeader("Content-Type", ContentType.c_str());
      int code = http.POST(data.c_str());
      payload = http.getString();
      http.end();
      return {payload, code};
    }
  public:
    void Setup(String ssid, String passwd)
    {
      WiFi.begin(ssid.c_str(), passwd.c_str());
    
      while(WiFi.status() != WL_CONNECTED) {
          delay(750);
      }

      http.setReuse(true);
    }

    bool isConnectedtoWifi() { return (WiFi.status() == WL_CONNECTED); }

    HTTPResponse PostRequest(String servername, String uri, String ContentType, String data)
    {
      return this->httpPOSTRequest(servername, uri, ContentType, data);
    }

    HTTPResponse GetRequest(String servername, String url)
    {
      return this->httpGETRequest(servername.c_str(), url.c_str());
    }
};

String SSID   = "";
String PASSWD = "";
String APIURL = "http://reefdripper.ddnss.org";

HTTPWIFI WifiHandler;

void setup() {
  if (watchdog_caused_reboot()) {
    printf("Rebooted by Watchdog!\n");
  } else {
    printf("Clean boot\n");
  }

  watchdog_enable(2000, true);

  Serial.begin(115200);
  WifiHandler.Setup(SSID, PASSWD);
}

void loop() {
  if (WifiHandler.isConnectedtoWifi())
  {
    Serial.println(WifiHandler.GetRequest(APIURL, "/data").response);
  } else {
    Serial.println("NOT connected");
  }
}

void setup1()
{
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop1()
{
  digitalWrite(LED_BUILTIN, HIGH);
  delay(75);
  digitalWrite(LED_BUILTIN, LOW);
  delay(75);
  watchdog_update();
}