FTDI‘s FT4222H Hi-Speed USB to SPI / I²C Bridging ICs Are Used in Automotive Vehicle Computer

An automotive vehicle computer with a fingerprint dongle for car networking is an advanced system designed to enhance vehicle security, personalization and connectivity. FTDI provides a USB to SPI bridge for the Vehicle Computer (VCU) to the Fingerprint Sensor. Here’s a detailed description of its components and functionalities.

The Fingerprint Dongle is a Biometric Sensor that is of a high-resolution fingerprint scanner that captures detailed fingerprint patterns.

Typically, USB is being used for connecting to the vehicle computer.

This system provides the following functionalities:

Enhanced Security

• User Authentication

The fingerprint dongle ensures that only authorized users can start and operate the vehicle. Each driver must authenticate using their fingerprint.

• Secure Access Control

Limits access to various vehicle features and settings based on user profiles, preventing unauthorized use.

Personalization

• Driver Profiles

Stores multiple driver profiles, each linked to a fingerprint. Profiles can include seat positions, mirror angles, climate control settings, infotainment preferences and more.

• Custom Settings

Automatically adjusts the vehicle’s settings to match the authenticated driver’s preferences, enhancing comfort and convenience.

Connectivity and Networking

• Vehicle-to-Everything (V2X) Communication

Enables the vehicle to communicate with other vehicles, infrastructure and devices to improve safety and traffic management.

• Telematics

Provides real-time data about vehicle status, location and performance to external systems and applications, supporting remote diagnostics and fleet management.

• Infotainment Integration

Connects to smartphones and other devices, offering seamless integration of navigation, media streaming and hands-free communication.

• OTA Updates

Supports over-the-air updates for firmware and software, ensuring the system is always up-to-date with the latest features and security patches.

Safety and Assistance

• Driver Assistance Systems

Integrates with advanced driver assistance systems (ADAS) such as lane-keeping assist, adaptive cruise control and automatic emergency braking.

• Emergency Services

Automatically contacts emergency services in the event of an accident, providing critical information like location and vehicle condition.

The driver enters the vehicle and places their finger on the fingerprint dongle. The dongle scans the fingerprint, processes the data and sends an encrypted authentication request to the VCU. The VCU verifies the fingerprint against stored profiles and if authenticated, powers up the vehicle systems.

If an unauthorized fingerprint is detected, the system remains locked and may alert the owner via a connected smartphone app.

By integrating a fingerprint dongle with a sophisticated vehicle computer, this system offers a secure, personalized and connected driving experience, enhancing both convenience and safety for users.

FTDI USB to SPI bridge ICs allow the perfect solution to this typical automotive application!

The example below uses FTDI’s FT4222H Hi-Speed USB to SPI / I²C Bridge to connect the Fingerprint Dongle to the VCU. This IC has the following key features making it an ideal candidate for this application:

• Single chip USB2.0 Hi-speed to SPI/I²C bridge with a variety of configurations.

• Entire USB protocol handled on the chip. No USB specific firmware programming required.

• On-chip OTP memory for USB Vendor ID (VID), Product ID (PID), device serial number, product description string and various other vender specific data.

• Configurable industry standard SPI Master / Slave interface controller.

• Support configurable data width with single, dual, quad data width transfer mode in SPI master.

• Configurable GPIOs can be easily controlled by software applications via USB bus.

• USB Power Configurations; supports bus-powered, self-powered and bus-powered with power switching.

• +5V USB VBUS detection engine.

• True 3.3V CMOS drive output and TTL input. (operates down to 1V8 with external pull-ups).

• Configurable I/O pin output drive strength; 4 mA(min) and 16 mA(max).

• Integrated power-on-reset circuit.

• USB2.0 Low operating and suspend current; 68mA (active-type) and 375µA (suspend-type).

• UHCI / OHCI / EHCI host controller compatible.

• Extended operating temperature range; -40℃ to 85℃.

• Available in compact Pb-free 32 Pin VQFN packages (RoHS compliant).

The block diagram shows at a high level how FTDI’s FT4222H can be integrated into this application.

Recommended ICs:

Any USB to SPI Master IC:

FT4222H

FT232H / FT2232H / FT4232H

FT4232HA