What is static? What is volatile? How does an interrupt work? What programming practices should typically be avoided in embedded systems, and why? Basic circuits questions: Ohms law. Voltage Dividers. Series and Parallel Resistors. Compare and contrast I2C, UART, and SPI How does an ADC work? How about a DAC? Compare and contrast Mutex and Semaphores Linked List algorithm questions String manipulation algorithm questions Bit manipulation algorithm questions Tell me about a hardware issue you debugged. Why would you use an RTOS? How does an OS manage memory?