Microsoft Corp.'s Smart Personal Objects Technology (Spot) initiative, first discussed during the November 2002 Comdex show, has just delivered product to the market. While first-generation Spot "infowatches" have met with a mixed reception in the trade press, the datacasting technology and low-power engineering behind them remain points of technical interest.
The Fossil Dick Tracy FX-3002 is one of the first Spot devices from a multivendor family of watch designs, all of which supply customized information such as stock quotes, sports, weather and news that is broadcast on FM subcarrier frequencies and linked to MSN Direct. Text messages can be received through MSN Messenger 6.0 as well. So that users may tailor data for display on their watch, each datacast item has headers to sort out whether a particular Spot device will accept or ignore the raft of information streaming in.
A development effort between Microsoft and National Semiconductor Corp. gave rise to the key ICs for the Spot engine. The processor chip (National's MM9662) contains an ARM7 CPU and needed ROM/SRAM and is supported by two 512-kbyte flash memory packages from Silicon Storage (SST39WF400A). National also supplies the custom radio chip (MM9642) receiver along with op amps (LPV321) and low-dropout regulators (LP3987, LP3883). A lithium-ion battery pulse charger (LTC4052-4.2) made by Linear Technology; a Maxim battery monitor (MAX6436); and two Torex voltage regulators (XC6202, XC9801) round out the power-management circuitry. Citizen Watch of Japan was chosen for the module manufacture.
With the rich set of electronics and always-on nature of the device, low-power design was a must given the internal 3.7-volt, 150-mA-hr Li-ion battery. Extending the wireless theme, a clever induction charger is used to ac-couple fresh juice through the hanging watch stand.
Estimated cost of goods sold for the FX-3002 is less than $30, a fraction of the $199 retail price. That suggests rich gross margins for the watch, but the possibility of inexpensive deployments of Spot modules in applications such as refrigerator info magnets, news fobs and embedded applications is perhaps even more intriguing.
Extracting monthly fees of $5 to $10 from a population swimming in data may be a bigger hurdle than the timepiece's somewhat bulky format. Business issues aside, the delivery of customized datacast information to your wrist speaks to the never-ending unwiring of data enabled by low-power, high-density electronics.
David Carey is president of Portelligent (www.teardown.com). The Austin, Texas, company produces teardown reports and related research on wireless, mobile and personal electronics.
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