Providing Bluetooth Functionality on Embedded Devices: A look at Embedded Operating Systems and Bluetooth Stacks Brian Fox Supervisors: Dr Greg Foster Prof. Peter Clayton

Introduction  Part of the Automated Wireless Identification System project  Specifically focused on how to expose Bluetooth functionality in embedded devices  I.e. design and build a custom OS image which exposes some form of API allowing access to the Bluetooth stack

Timeline  Look at the various OS builders in use for various embedded OS’s  This entailed identifying and studying the architecture of some embedded OS’s on the market and looking at the tools provided to help create a custom image for that OS  Create and build own custom Windows CE.NET platform

Problems involved with Embedded Systems Design  Hardware / Software partitioning  What parts of the solution should be implemented where?  Can lead to integration problems in later development stages  Power  Some microprocessors can operate in “sleep mode” and only wake up on a timer tick  Debugging  Hooks provided in microprocessor circuitry

Embedded Operating Systems  Highly modular/componentised  Support wide variety of target hardware and processors through use of BSPs  Real-time  Power management

Windows CE.NET  Designed around mobile devices  Minimum footprint of 200k  Actual footprint currently  Power management  “Instant On”  Control of device level power states  Wide range of board support packages (BSPs)  Microsoft is the only vendor to supply a Bluetooth stack with the operating system

Windows CE.NET Architecture

Platform Builder  Integrated Development Environment  Provides the means to create, build, deploy and debug a custom image of the OS  Provides an emulator to allow for simultaneous hardware and software development  Automatically determines dependencies between modules  Practical experience  Have built a headless operating environment exposing Bluetooth functionality through the WINSOCK API

Platform Builder

QNX Neutrino  Designed around microkernel and central software bus  “Plug-in” type architecture  Inter-process communication via message passing handled by the microkernel  OS exposes standard POSIX API  Platform creation either manual or through use of the Momentics Professional Edition IDE  Will run on multiple host platforms

QNX Neutrino Architecture

Wind River VxWorks  Modules implemented on top of the core OS  Core OS consists of a microkernel and debug agent and interacts with the BSP  Platform creation either manual or through use of the Torando IDE

Bluetooth Stacks  Means by which the OS and applications access and control the Bluetooth hardware  Expose an API to application developers  Modular in concept and design  May need to be ported to a specific OS  Bluetooth Qualification  Need to implement all core stack layers and Generic Access Profile and Serial Port Profile

Microsoft Bluetooth Stack

Stonestreet One Bluetopia

Where to from here?  Test and debug practical image  Hopefully deploy onto a development board for full testing with the other team members

Questions?