Dive deep into the Raspberry Pi Pico and RP2040 microcontroller in this comprehensive second class of the HackadayU series. Explore GPIO registers, timer peripherals, and alarms before delving into interrupts, NVIC, and the vector table. Follow along with practical code examples, including dumping the vector table using the VTOR register and implementing a blink function with interrupts. Gain insights into the WFI (Wait for Interrupt) instruction, Cortex-M CPU registers, and essential ARM instructions such as mov, add, sub, and mul. Master bitwise operations with and, orr, and eor (xor) instructions. Conclude with a live demonstration of WFI power saving using the Nordic PPK2, providing hands-on experience with advanced microcontroller concepts and programming techniques.