Parse V2I Custom Binary Protocol | Dataford Interview Questions

Write a parser for a custom binary protocol used in vehicle-to-infrastructure communication for Waymo.

Implement parse_vehicle_messages(data) for a byte stream containing zero or more frames. Each frame is 0xA5 0x5A, followed by version, message_type, a two-byte little-endian payload length, the payload, and a two-byte little-endian checksum. The checksum is the sum of all bytes from version through the payload, modulo 65536.

Return valid frames as dictionaries with keys version, type, and payload, where payload is a list of integers. Ignore noise, invalid checksums, and incomplete frames, then continue scanning for later valid synchronization markers.

Constraints

0 <= len(data) <= 4096
Each byte is an integer from 0 through 255
The synchronization marker is [165, 90]
The payload length is an unsigned 16-bit little-endian integer
The checksum is the sum of version, type, length bytes, and payload bytes modulo 65536

Function Signature

def parse_vehicle_messages(data):

Your question is Parse V2I Custom Binary Protocol. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Write a parser for a custom binary protocol used in vehicle-to-infrastructure communication for Waymo.

Constraints

0 <= len(data) <= 4096
Each byte is an integer from 0 through 255
The synchronization marker is [165, 90]
The payload length is an unsigned 16-bit little-endian integer
The checksum is the sum of version, type, length bytes, and payload bytes modulo 65536

Function Signature

def parse_vehicle_messages(data):

Your question is Parse V2I Custom Binary Protocol. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.