Drivers and bring-up: interview prep

Interview questions

Key points for each answer are in the app's question bank.

1. Compare polling, interrupts and DMA. When would you choose each?Basic
2. Design the API for a non-blocking UART driver.Intermediate
3. Explain SPI's four modes and how chip select is handled.Basic
4. Walk through an I2C transaction: start, address, ACK, data, repeated start, stop.Basic
5. An I2C bus is stuck with SDA held low. How do you recover?Intermediate
6. How do you choose I2C pull-up resistor values?Intermediate
7. Implement a software debounce for a push button.Basic
8. Push-pull versus open-drain outputs: when would you use each?Basic
9. Measure an input signal's frequency with a timer.Intermediate
10. How do PWM frequency and duty-cycle resolution trade off?Intermediate
11. What affects ADC accuracy, and how do you improve it?Intermediate
12. What's the difference between an independent watchdog and a window watchdog?Basic
13. What happens in hardware when an interrupt fires on a Cortex-M?Intermediate
14. What contributes to interrupt latency, and how do you reduce it?Intermediate
15. Explain NVIC priority grouping: preemption priority versus subpriority.Intermediate
16. How would you structure a HAL so application code ports across MCU families?Intermediate
17. What does a bootloader do, and why must the vector table be relocated?Intermediate
18. You receive a brand-new board. In what order do you bring it up?Intermediate
19. You must write a driver for a new sensor. What do you read first in the datasheet?Basic
20. How does the clock tree affect peripherals when you change the PLL?Intermediate

Hands-on challenges

Design rounds

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