Study On Wearable Computer Hardware Technology

Wearable Computer is staying in the primary stage of development currently. And now, it is just a new way of usage of general computer. There is no related specification and standard about wearable computer because of the development of some technologies. There is no application specific hardware for wearable computer as well except for a few input and output devices. In this paper, the common building method of wearable computer hardware system, i.e. the System-Level development method based on COTS devices, and some advantages and shortages of this method are introduced firstly. The simple description of prototype based on COTS devices verifies those shortages of COTS technology. Thus, the neccessity to explore and research new hardware scheme suitable for wearable computer is elicited. In this paper, wearable computer is regarded as an embedded computer system. The relationship between them is analyzed. Then some general concepts of embedded system and basic principles to choose embedded devices are stated. On basis of these things, Intel RISC SOC PXA270 and graphics accelerator PXA2700G which all are for mobile Handsets and Handhelds are employed to be the core of this new wearable hardware system in this paper. After that, three advanced technologies of PXA270, i.e. WirelessMMX, Quick Capture and SpeedStep are detailedly introduced. What's more, the requirement analysis for the whole hardware system is given. Finally, under the guidance of related development materials, the overall design and the detailed circuit schematics of whole wearable computer hardware system are given. At the same time, the initial implement scheme of the corresponsive PCB board is presented. The analysis for Intel PXA270 in this paper indicates that PXA270 is characteristic of low power consumption, high performance, and rich function interfaces. These make PXA270 very suitable for mobile and portable computing device such as PDA(Personal Digital Assistant), PMP(Portable Media Player)and smartphone. Of course, it fits for wearable computer which has punitive requirement on function, performance, power consumption, volume and weight. Obviously, it's more difficult to employ SOC similar to PXA270 to do Board-Level development of wearable computer than the way based on COTS devices. What's more, there is no anaglous reference design. On the other hand, the Board-Level development is much more flexible. To meet the actual demand, any needed function can be added to or deleted from the system. That is too say, the Board-Level is more configurable. Meanwhile, the developing experience and method of PDA , PMP and smartphone can be fully used for reference.