Failsafe uptime with watchdogs.
Common runtime reliability issues when devices lack proper watchdog systems or good practices:
Infinite Loops and Code Hangs The microcontroller gets stuck in endless loops due to buggy code, waiting for conditions that never occur, or polling operations that freeze. Without a watchdog timer, the system remains unresponsive indefinitely.
Memory Leaks and Stack Overflow Poor memory management causes the device to gradually consume all available RAM, leading to crashes or erratic behavior. Stack overflow from deep function calls or large local variables can corrupt memory and cause system freezes.
Interrupt Service Routine (ISR) Problems Interrupts that take too long to execute, nested interrupts that overwhelm the system, or ISRs that get stuck can prevent the main program from running properly, causing the entire system to hang.
Hardware Peripheral Lockups Communication interfaces like SPI, I2C, or UART can hang waiting for responses from unresponsive external devices. Without proper timeouts or error handling, the MCU waits forever for data that never arrives.
Clock and Power Management Failures Incorrect clock configurations, power supply instabilities, or brown-out conditions can cause the processor to run at wrong speeds or enter unexpected sleep states without proper recovery mechanisms.
External Component Dependencies The system hangs when external sensors, memory chips, or communication modules fail or become unresponsive. Without fallback strategies, the MCU waits indefinitely for these components to respond.
Race Conditions and Timing Issues Multiple tasks or processes competing for the same resources can create deadlocks where the system becomes stuck waiting for resources that will never be released.
Unhandled Exception States Division by zero, accessing invalid memory addresses, or other runtime errors that aren't properly caught can cause the processor to enter fault states from which it cannot recover without a reset.
