Embedded & IoT
Microcontrollers & Firmware
5 practice questions. Free questions open a full answer guide; the rest unlock with Pro.
- Why do you mark a variable shared between an interrupt service routine and your main loop as volatile, and what does volatile NOT protect you from?
- You're shipping firmware to a fleet of devices in the field that support over-the-air updates. How do you design the update and watchdog strategy so a bad image can't permanently brick a device you can't physically reach?Go Pro
- Your firmware sets a variable inside an interrupt handler and the main loop reads it, but the main loop occasionally acts on a stale value or seems to never see the change at all. How do you reason about what's going wrong and fix it?Go Pro
- What is a watchdog timer, and how would you use one correctly so it actually catches a hung firmware instead of masking the bug?Go Pro
- A shipped microcontroller product corrupts a sensor reading roughly once a day with no crash. How do you investigate it?Go Pro
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