Appliance Design - October 2007 - (Page 32)

ELECTRONICS a USB interface to an MCU using simple and well-understood communications interfaces, such as RS232 or SPI. Vinculum is derived from a Latin word, meaning to bind or tie. The term was chosen because the FTDI Vinculum device ties together the worlds of USB peripherals, hosts and traditional interfaces. In mathematics, a horizontal bar across two or more terms, showing that they are to be treated together, is also a Vinculum. With the FTDI approach, adding a USB host controller is straightforward, as all the elements needed come in a single-chip solution. To make it even easier, FTDI has produced two snap-in panel-mounting modules containing the Vinculum device, VDRIVE and VMUSIC. Both require only a four-signal pin connection to the control unit of an appliance, and the VMUSIC module includes an MP3 decoder and audio line out. Within the Vinculum chip are an 8-bit processor, two dedicated DMA (Direct Memory Address) engines, and a 32-bit co-processor to handle the file functions. Popular USB device class stacks are integrated within the Vinculum chip, together with FAT12/16/32 support for USB flash drive applications, thus freeing the product designer from the development and support of these complex and time-consuming layers. The device is supplied with royalty-free firmware binaries developed in a high-level assembly language and have simple DOS-like high-level commands for USB peripheral control and data transfer. The Vinculum interface to the application MCU can be a traditional UART, SPI or a FIFO. Vinculum can control two USB interfaces complying with Full Speed Fig. 3. Circuit schematic shows ease of interface to appliance microcontroller. USB 2.0 (which includes the USB 1.1 and Low Speed USB). Each interface can be configured as either a slave or a host, depending on the firmware chosen. Vinculum device programming is through the UART interface with upgrades via either UART or USB flash drive. (See Fig. 2.) Supporting the device are development boards, reference designs, including a data-logging module, and the VDRIVE and VMUSIC interface modules. VDRIVE is a simple way to add a USB flash drive interface to an application. It is a snap-in module for panel mounting, with a single USB socket and a traffic indicator LED on the surface. It interfaces through an 8pin connector, with four signal pins and PWR, GND and wake-up from the low power sleep mode. (See Fig. 3.) The VMUSIC interface module is a larger snap-in module, with the ability to play back MP3 and other music formats directly from the USB flash drive. In addition to the functionality of the VDRIVE, the VMUSIC module also has line out and a 3.5 mm stereo head- set jack socket. (See Fig. 4.) Since the introduction of Vinculum, FTDI has been working with many different companies to evaluate new application areas for USB flash drives. Most of these are at varying levels of confidentiality, as companies seek to use USB to gain a competitive edge. One interesting area is in the control of HVAC/R equipment. The USB flash drive can be used, just as in the example of the oven, to load new programming data into the control panel, perhaps to respond to changing use by the system user or to add new equipment. But it can also be used to capture monitoring data for relatively long periods of operations, depending on the capacity of the flash drive, which can be analyzed off-line to improve the performance of the system. Makers of commercial, coin-operated appliances are also looking at USB flash drives as a tool for upgrading firmware to add new features, to add new product options in dispensing machines, and to upgrade the coin sensor technology in the continual battle with fraudsters. Using a VMUSIC module instead of just a visual interface allows the product to talk an operator through different steps in making changes and upgrades. Adding USB is a new way to provide product differentiation, both through the USB itself and through the possibility of upgrading to add new features. It is still at early stages, but as developers become more familiar with the technology, new and exciting applications will eventually emerge. FTDI is providing tools that make adding this technology as simple as possible. < Fig. 4. VMUSIC2 module from FTDI. For more information, enter. . . . . . . . . . . . . . . . . . . . . 306 Or email: sales1@ftdichip.com www.applianceDESIGN.com 32 applianceDESIGN October 2007 http://www.appliancedesign.com

Table of Contents Feed for the Digital Edition of Appliance Design - October 2007

Contents Editorial Shipments/Forecasts News Watch Applying Powder Coatings to Plastic Parts is No Longer a Pipe Dream New Technology Platform Provides the Ability for a single IC to Control Two- Motors in a Single Appliance, Simplifying Motor Control Design Advanced Motor-Control Techniques have Become More Accessible to a Wider Array of Appliances, Helping to Improve Efficiency and Reduce Noise Adding USB Host Capability to Appliances Permits In-Field Programming and Acquisition of Test Data ZigBee Modules Make it Easier to Design Wireless Connectivity into Applications New Concepts such as Rapid Tooling and Rapid Injection Molding Provide Stepping Stones Between Prototyping and Full Scale Production A Number of Factors and New Developments Affect the Decision on Whether to Build Prototypes In-House or Outsource to a Service Bureau DesignMart Advertiser’s Index Association Report: CEA

Appliance Design - October 2007

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