I've been working on a project with Atmega328PB microcontroller using both the UARTs for communication. The controller runs fine for a long time but all of a sudden it does not respond at all. It happened two times in a span of one week. The weird issue is, it does not even respond to hardware reset, i.e., connecting RESET pin to ground. But it works normally if it is powered off by removing the supply and connecting it again. It is supplied with a 4V source with a 100nF capacitor to the Vcc pin of the controller and RESET pin is pulled up through a 10K resistor. Below is the schematic of the circuit.
My questions are :
- Is it a hardware or a software problem?
- FYI, it has extensive use of pointers for string manipulation. Does memory leaks cause the issue?
- It has WDT (Watch dog timer) implemented. Does it affect the Hardware reset?
- What could be cause of this problem? Did any body face this kind of issue?