To view an on-demand seminar featuring Motorola's wireless monitoring system, click here.
Motorola Inc.'s consumer arm has rolled out a product that watches over homes, businesses or other places and records events when triggered by a variety of sensors. While conceptually nothing new, the product is interesting for the steps it takes to bring remote-viewing capability to the consumer (as opposed to the commercial customer). As the footprint of electronics within the digital home grows, the integration of security functions represents a logical step.
The Motorola HMEZ1000 base package comes with a USB interface-enabled basestation (HMGW1070) and a wireless camera (HMWL1010) that communicates back to the basestation. The wireless camera records either color video with audio or still photos. The basestation serves as the communication hub in the setup, with the USB interface used to connect the system to a host PC network for broadband Internet connectivity.
Any recorded images are stored on the connected computer for later viewing, or if immediate notification of an event is required, the basestation can send images and text alerts to a cell phone or as an e-mail attachment. True to form for consumer products — which often fare best with "up sell" items — the HMEZ1000 has optional accessories. The basestation supports sensor additions of up to six wireless cameras, three wired cameras and eight noncamera monitors. The latter category includes water, door/window intrusion and temperature sensors.
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To enable sensor-to-base wireless communications, the HMEZ1000 has two RF channels. A direct-sequence spread-spectrum radio operating in the 2.4-GHz ISM band serves for transmission of video and audio signals. A second channel in the 418-MHz band — also available for unlicensed use — handles control and data polling for remote devices and sensors. Communication between camera and basestation is good for up to 25 meters, depending on the obstacles separating the devices.
With proper lighting, objects up to 200 feet away can be captured in the camera, which has a viewing angle of 80°. The motion sensor can detect objects up to 4 meters away, also with an 80° field of sensing. Microphone range is shorter, adequate for picking up a normal conversation 2 to 3 meters away.
The wireless camera comprises several pc board assemblies. A front-facing board supports the OmniVision OV7910 1/3-inch color CMOS image sensor, which captures video at either PAL or NTSC resolution. The same board hosts the device used for motion detection, a Heimann LHi954 pyroelectric detector. A second board implements the 2.4-GHz audio/video link based on a Fujitsu MB15E07SLPFV1 PLL frequency synthesizer and a fistful of discretes for the rest of the link.
Both the camera and transmitter boards are interfaced to a third board, which receives control signals from and transmits status data to the basestation over the 418-MHz link, enabled by a Chipcon CC1000 RF transceiver.
Two 8-bit microcontrollers from Microchip on the third board — the PIC16LF628 (Data Sheet, Technical Paper) and the PIC16F874 (Data Sheet, Technical Paper) — control the two radio subsystems and the camera as a whole.
The basestation also comprises three basic subassemblies. Completing the 2.4-GHz link with support for as many as six wireless cameras, a receiver module incorporating a Fujitsu MB15E07SLPFV1 PLL frequency synthesizer, a Zarlink SL1461SA PLL FM demodulator and an NXP TDA9820 TV FM demodulator join with discrete semiconductors for the radio implementation. The board to which the 2.4-GHz receiver mounts also has a 418-MHz radio, to receive data from other wireless sensors and to support duplex control with wireless cameras. A Chipcon CC1000 transceiver and a Microchip PIC16LF628 MCU on the 418-MHz radio team with two other Microchip 8-bitters (PIC16C58B/PIC16F874) and a National Semiconductor LM1881 video sync separator to complete the radio subsystem.
The final board in the basestation handles signal multiplexing with an NXP HEF4052 dual four-channel multiplexer. Audio/video encoding is implemented by an NXP SAA7113 9-bit video processor and an Oki Semiconductor MSM7716 14-bit linear PCM codec. To complete the path to the USB connector of the basestation, a Nogatech NT1004 USB video and audio interface joins with 256 kbytes of GLink DRAM (GLT440L16) and a Microchip 16-kbyte E2PROM (24LC16B) for operating code.
The board assembly markings indicate that China's ODM Xanboo is behind the design and implementation, with Motorola serving as the branded retail name for the kit.
Using a more discrete-intensive design with smaller-scale integration chips keeps cost low. No ASICs were developed in creating what is likely a modest-volume product; as such, the HMEZ1000 kit sells for about $250. Given the extensive (and reassuring) capabilities provided by the setup, we expect to see more designs of this type emerge.
Component focus
Because of the rather low-level-integration of the semiconductor set and the somewhat fragmented physical implementation of both camera and basestation, the HMEZ1000 has a hearty appetite for passive components, crystal oscillators and board-to-board connectors. Electrolytic capacitors are especially plentiful, serving to tame noise, maintain signal quality and enable ac coupling of A/V signals passing between integrated circuits. The connectors are almost exclusively hand-soldered pin header connectors and cable connectors, indicative of the plentiful low-cost assembly possible with the choice of China for final manufacture. Enclosures, too, require a fair amount of manual labor for both plastics fitting and screw-assembly closure, seen in both halves of the HMEZ1000 design.
For a more complete parts list for the basestation, click here. For a more complete parts list for the camera, click here.
David Carey is president of Portelligent (www.teardown.com). The Austin, Texas, company produces teardown reports and related industry research on wireless, mobile and personal electronics.
