Lab 4 tasks

Work in labs/mouse/. Build a parser that survives command responses, mid-stream starts, and invalid packets without poisoning the input stream.

Requested functions

• int mouse_enable_data_reporting(void)
• int mouse_disable_data_reporting(void)
• int mouse_process_byte(uint8_t byte)
• int mouse_get_packet(mouse_packet_t *packet)

Guided gaps

Choose retry counts, validate ACKs, buffer three bytes, drop bytes until the synchronization bit marks byte 0, and convert signed movement to C integers. Keep these decisions visible for the final project.

IMPORTANT

Do not assume the first byte you receive is packet byte 0. Robust code must resynchronize when a stream starts mid-packet.

Common mistakes

Forgetting that X and Y have separate sign bits, treating overflow bits as movement, returning a packet before all three bytes arrive, and leaving data reporting enabled after a test. If a demo cursor jumps wildly, inspect synchronization and sign extension first.

Next: checks and references.