Hello,
I usually always find a solution on this forum (or wherever). But this problem is giving me hard time... So I decided to activate my account, and ask 
.. so sorry for the long topic to come...
The context : I'm using Tinkercad to work on a small project of "framework". It's quite easy to learn and try with this. I ended up with finally a really basic electrical scheme (diodes and buttons), because the interesting part is inside the card. I know that it will never work on UNO (it will be on MEGA), but as a playground, I try every features with just less functions...
I'm using a lot the SRAM monitoring to detect when I'm running out, or when I've a leak, and it works pretty well.
But since I've implemented my last class, I'm facing to a weird problem.. I'm almost sure I'm running out of memory, but I can't prove it, and it is really annoying...
Here is what happen: the card is rebooting itself with some continuous " ? ? ? " characters. If I comment the line that make it fall from OK to KO, the program works again, it can be on any line, but most of the time, it happen on a Serial.print(F("Blablah")). As it is a playground, I let it commented, and I continue. But soon or later, I face again to this strange situation on another line... and it's always when I free up some memory (reduce array for example) that system works again.
However, Sram monitoring can sometime indicate 900bytes available and issue happen ! ...
I thought a time, that it was FLASH memory that was full, but not.... when I copy/past my program in the Arduino IDE I even don't overtake 60%...
When I execute step by step it can happen on the very first lines of setup...
Is there something I missed in terms of memory usage ? is it possible that SRAM usage is not the exact reality ? (Until now when I see that I reach 0; I can see UNO flickering..) .
Or is it possible that Flash memory is full, and the IDE indication is wrong ?
Any experience to share with me would be very nice !
I'm not using Strings, I use PROGMEM every time I can. I only used 2 times a Calloc (but there are only called one time in constructor). All class I use are global.
Below, you'll find the setup function. In the current situation, system reboot continuously between Serial.begin and the first Serial.println(F("--MAIN : Don't forge...
this happen because I added at the end "Serial.print(F("--ERRORS_HANDLER : Errors storage capacity...
If I comment this line, It continues to work like before... whereas Sram is about 900bytes at this time of the execution...
void setup(){
Serial.begin(NETWORK_SERIAL_SPEED);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
Serial.println(F("--MAIN : Don't forget to remove serial.begin when releasing.."));
// Pin configuration
//BOF:BUTTONS
pinMode(PUSH_BUTTON_1, INPUT);
pinMode(PUSH_BUTTON_2, INPUT);
pinMode(PUSH_BUTTON_3, INPUT);
pinMode(PUSH_BUTTON_4, INPUT);
pinMode(PUSH_BUTTON_5, INPUT);
//EOF:BUTTONS
//BOF:EEPROM
pinMode(EEPROM_PINOUT_ACCESS_MODE, INPUT);
//EOF:EEPROM
//BOF:LIGHT
pinMode(LIGHT_PINOUT_LED_1, OUTPUT);
pinMode(LIGHT_PINOUT_LED_2, OUTPUT);
pinMode(LIGHT_PINOUT_LED_3, OUTPUT);
pinMode(LIGHT_PINOUT_LED_4, OUTPUT);
//EOF:LIGHT
//BOF:7 SEGMENTS DISPLAY
pinMode(PINOUT_BCD_2_1, OUTPUT); //0001
pinMode(PINOUT_BCD_2_2, OUTPUT); //0010
pinMode(PINOUT_BCD_2_3, OUTPUT); //0100
pinMode(PINOUT_BCD_2_4, OUTPUT); //1000
//EOF:7 SEGMENTS DISPLAY
//BOF:EEPROM
uint16_t analogEepromAccessMode = analogRead(EEPROM_PINOUT_ACCESS_MODE); // read the input pin
_eepromAccessMode = EEPROM_ACCESS_MODE_DISABLE;
if(analogEepromAccessMode >= (uint16_t)(ARDUINO_ANALOG_READ_RESOLUTION * (0.25)) ) _eepromAccessMode = EEPROM_ACCESS_MODE_READ;
if(analogEepromAccessMode >= (uint16_t)(ARDUINO_ANALOG_READ_RESOLUTION * (0.75)) ) _eepromAccessMode = EEPROM_ACCESS_MODE_WRITE;
//EOF:EEPROM
//BOF:CLASSES INITIALIZATION
uint16_t startAddress = EEPROM_FIRST_CLASS_USABLE_ADDRESS;
//framework classes
_tools = new Tools();
_tools->monitorMinFreeRam();
_handler = new ErrorsHandler("mainEH");
_eeprom = new Eeprom("mainEE",1, startAddress, MAIN_COUNT, sizeof(*_variables));
for(uint8_t position = 0; position < MAIN_COUNT; position++) {
_eeprom->load(&_variables[position], position);
}
startAddress += _eeprom->getSize();
_network = new Network("mainNET");
//pointer recopy for cross relations
_handler->setEeprom(startAddress);
startAddress += _handler->getPersistentSize();
_handler->setNetwork(_network);
//device classes
_l1 = new Light("L1", startAddress, LIGHT_PINOUT_LED_1);
startAddress += _l1->getPersistentSize();
_l2 = new Light("L2", startAddress, LIGHT_PINOUT_LED_2);
startAddress += _l2->getPersistentSize();
_l3 = new Light("L3", startAddress, LIGHT_PINOUT_LED_3);
startAddress += _l3->getPersistentSize();
_l4 = new Light("L4", startAddress, LIGHT_PINOUT_LED_4);
startAddress += _l4->getPersistentSize();
//EOF:CLASS INITIALIZATION
// WELCOME SCREEN
Serial.println(F("--################### ARDUINO DEMO BOARD ######################"));
Serial.println(F("--# Framework testing : Error Handler object 05/2020 #"));
Serial.println(F("--#############################################################"));
//debug
Serial.print(F("--FRAME : Size of Frame object is: "));
Serial.println(sizeof(_inbound));
Serial.print(F("--EEPROM : Access mode set to: "));
Serial.println(_eepromAccessMode);
Serial.print(F("--ERRORS_HANDLER : Errors storage capacity: "));
Serial.println(_handler->getMaxStoredErrors(false));
//BOF:NETWORK
_network->clearFrame(&_inbound); // inbound frame initialization : ready to receive
_network->clearFrame(&_outbound); // outbnound frame initialization : ready to send
//EOF:NETWORK
}
