ESP32 reboots unexpected - problematic variable? - c++

Question

I have a problem with (at least) one row in my code. My intention is to instantiate some objects for HTTP requests. I store their pointers in an array requestsBatch because I will call them from within a helper function. After storing them I'll do some time checks and then send the request to the server. After a successful request, the object will be deleted.
It seems the variable address is problematic but I can't see why.
const char* root_ca_sherz = "myCert";
int currentRequestsBatchIndex=0;
class HTTPREQUESTS {
public:
HTTPREQUESTS(String strAddress = "", String strParameters = "", bool bSendImmediately=false, const char* cert=root_ca_sherz) {
address = strAddress;
parameters = strParameters;
certificate = cert;
currentRequestsBatchIndex++;
Serial.println("New object instantiated");
Serial.println(address);
Serial.println(parameters);
}
~HTTPREQUESTS() {
currentRequestsBatchIndex--;
}
bool sendRequest() {
Serial.println("Called from within sendRequest()");
Serial.println(address); // <<<<<< THIS ROW CAUSES THE REBOOT
/*
http.begin(address+"/"+parameters, certificate); //, root_ca_sherz
int httpCode = http.GET();
Serial.print("HTTP Code: ");
Serial.println(httpCode);
Serial.print("Payload: ");
Serial.println(http.getString());
if (httpCode > 0) { //Check for the returning code
return true;
}
else {
Serial.println("Error on HTTP request");
return false;
}
http.end();
delay(1000);
return false;
*/
return true;
}
private:
const char* certificate="";
String parameters;
String device;
String address;
unsigned long timestamp=0;
int sendAttempts=0;
bool sendImmediately = false;
unsigned long lastSendAttemp=0;
};
HTTPREQUESTS *requestsBatch[5];
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
delay(3000);
Serial.println("Ready");
String address = "https://myAddress.com";
String parameters = "?secret=XXXXX&deviceName=deviceName&status=1&value=999&time=123456789&functionName=functionName";
HTTPREQUESTS *req01 = new HTTPREQUESTS(address, parameters);
// Store pointer to array to use it later
requestsBatch[currentRequestsBatchIndex] = req01;
Serial.println("Object stored in array");
Serial.print(F("Send request: "));
if(requestsBatch[0]->sendRequest()) {
//delete requestsBatch[0];
Serial.println("requestsBatch[0] deleted");
}
}
void loop() {
// put your main code here, to run repeatedly:
}
SOLUTION:
Replacing
currentRequestsBatchIndex++;
by
if(address != "") {
currentRequestsBatchIndex++;
}
because currentRequestsBatchIndex is also incrementing when creating the empty *requestsBatch[5] array.

Answer 1

As I dont like the String class (will cause you memory problems later on)I rewrote with char arrays and it works as expected (Included your "solution" but have you checked serial monitor output):
const char* root_ca_sherz = "myCert";
char address[128] = {'\0'};
int currentRequestsBatchIndex = 0;
class HTTPREQUESTS {
public:
HTTPREQUESTS(char strAddress[128] = {'\0'}, char strParameters [128] = {'\0'}, bool bSendImmediately = false, const char* cert = root_ca_sherz) {
strcpy (address, strAddress);
strcpy (parameters, strParameters);
certificate = cert;
if (address[0] != '\0') {
currentRequestsBatchIndex++;
}
currentRequestsBatchIndex++;
Serial.println("New object instantiated");
Serial.println(address);
Serial.println(parameters);
}
~HTTPREQUESTS() {
currentRequestsBatchIndex--;
}
bool sendRequest() {
char testAddress [128] = {'\0'};
Serial.println("Called from within sendRequest()");
strcpy (testAddress, address);
Serial.print("Will work: ");
Serial.println(testAddress); // <<<<<< THIS ROW CAUSES THE REBOOT
Serial.print("Will also work: ");
Serial.println(address); // but over written at next creation
/*
http.begin(address+"/"+parameters, certificate); //, root_ca_sherz
int httpCode = http.GET();
Serial.print("HTTP Code: ");
Serial.println(httpCode);
Serial.print("Payload: ");
Serial.println(http.getString());
if (httpCode > 0) { //Check for the returning code
return true;
}
else {
Serial.println("Error on HTTP request");
return false;
}
http.end();
delay(1000);
return false;
*/
return true;
}
private:
const char* certificate = "";
char parameters[128] = {'\0'};
char device[128] = {'\0'};
// char address[128] = {'\0'};
unsigned long timestamp = 0;
int sendAttempts = 0;
bool sendImmediately = false;
unsigned long lastSendAttemp = 0;
};
HTTPREQUESTS *requestsBatch[5];
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
delay(3000);
Serial.println("Ready");
const char address[] = "https://myAddress.com";
const char parameters[] = "?secret=XXXXX&deviceName=deviceName&status=1&value=999&time=123456789&functionName=functionName";
HTTPREQUESTS *req01 = new HTTPREQUESTS(address, parameters);
// Store pointer to array to use it later
requestsBatch[currentRequestsBatchIndex] = req01;
Serial.println("Object stored in array");
Serial.print(F("Send request: "));
if (requestsBatch[0]->sendRequest()) {
//delete requestsBatch[0];
Serial.println("requestsBatch[0] deleted");
}
}
void loop() {
// put your main code here, to run repeatedly:
Serial.println("Still running !");
delay(1000);
}