You've heard the stories, you've read the headlines: adding connectivity to existing products is all the rage. Seems like any product can be equipped for instant ROM updates, e-mail communication, or Web browsing. At times it seems absurd, but eventually it makes sense: a refrigerator can automatically reorder foodstuffs and refreshing beverages; MP3 audio players could seek out new material based on the owner's musical tastes. Even a lowly gardening implement such as a hand trowel could be equipped to send soil pH data to a wireless station which could communicate with a landscaping supply business for topsoil replenishment.
You snicker, but it's real. All it takes is adding some complex circuitry to a product, normally customizing it to best suit your product's needs - which could range from simple text messaging to complex data transmission or multimedia image streaming. There are several ways to accomplish this, but the best known is the embedded route, where the needed circuitry (typically a processor, media access controller, [MAC], physical layer [PHY], ROM, and RAM) is worked directly into an electronic product's innards to provide peripheral connections, onboard memory, voltage supplies, serial/direct memory access, (DMA) controllers, I/O lines, and so forth.
Lantronix has come up with a single-chip solution that, for many vendors, may provide a simpler path. Lantronix suggests a vendor could use DSTni as an interim to developing a true embedded comm system. This could result in better integration, but would likely take a longer time to implement than a one-chip solution. And in the time-to-market crazy world we live in, they have a point.
Though DSTni is applicable to consumer products, the company points to network-enabled, peer-to-peer systems as a primary goal. Hence a developer would use it to network-enable not a simple light switch but rather a lighting panel, which would in turn be networked to a building control center incorporating controls for HVAC, heating, and security systems.
Other potential applications include intelligent proximity card readers, which would identify and process employee information and activate appropriate door locks or other elements of a security system. Currently, Lantronix says, such systems require cumbersome cabling and communication with a central server to implement; constructing a card reader/door activator system with more direct connectivity would decrease costs and system complexity.
The goods
DSTni includes pretty much all a vendor would need to get a hand trowel or any other product connected. As Figure 1 shows the chip incorporates a 16-b 80186-design CPU (software-clock controllable from 12 to 96 MHz) with 150K gates, two Ethernet MAC controllers, an integrated 10/100 Ethernet PHY and support for 100Base-FX (fiber). It supports the Ethernet standards 802.3, 802.3u.
It also includes 256 KB of SRAM (with no wait state), integrated CANBUS and USB hardware support, four DMA serial ports (these can work with either RS-232 or RS-485 connectors, with up to 460-kbps connection speed), as well as parallel I/O functionality. A programmable watchdog timer circuit is also included for timeout purposes.
Each asynchronous serial port has a programmable baud-rate generator and supports 7-, 8-, and 9-b operations with standard parity options and the capability to transmit break characters and interrupts (the latter occurring when a valid data word has been received). The ports may use DMA for transmit or receive functions.
The serial controller can be tapped to address up to 32,000 addresses through these ports, which can support sustained data transfer rates up to 1 Mbps. DSTni's parallel I/O structure works with 32 pins which can be configured for input, output, or alternate pin sharing.
The chip will work in fairly extreme environments (from --40 to 85 F, making it suitable for the aforementioned HVAC and building-control applications.
In a typical application, as shown in Figure 2 engineers could attach DSTni to several RS-232 ports to a data-gathering device. For example, in a healthcare setting, the device could be used to network-enable handheld, serial-based blood analyzers. Such analyzers would often be hooked up through dedicated RS-232 cabling to an infrared link at each nurse's station, with each link then connected to a central data-collecting station. By hooking the data-collectors for these analyzers to the DSTni serial ports, the devices could connect directly to the facility's Ethernet network, and data could be routed anywhere within the building or remotely via TCP/IP.
For a more communication-specific example, consider a telecom provider needing to improve its remote-management capabilities for telephone switches, especially in terms of (ASCII)-based network alarm delivery. Some modern switching equipment includes remote-alarm management functions but may be out of reach for budget-conscious companies. By using a device like DSTni to act as a translator for legacy systems, the company may be able to provide system-wide alarms (to a central server) in the event of remote-hut power losses, switch failures, and other mishaps.
Support kit
Lantronix rounds out the DSTni package with a developers kit, containing a reference design board, networking software, US Software's SuperTask real-time operating system (RTOS), a TCP/IP stack that enables management through a standard Web browser, and a set of sample source code and C libraries. Since the chip's CPU section is based on the x86 architecture, the standard registers for that processor type work with DSTni.
The DSTni will be available in the fourth quarter of this year in a 12x12-mm, 180-pin BGA package. Pricing was not finalized as of press time but is expected to be in volume between the range of $20 to $25, including soft-ware. For more information, contact Lantronix at 15353 Barranca Parkway, Irvine, CA 92618. Phone: 949.453.3990. Fax: 949.453.3995.
URL: www.lantronix.com.
John Poultney is the Executive Editor of Communication Systems Design. When not dismantaling walkie-talkies, he can be reached at jpoultney@cmp.com.
