OTT201 Building Embedded Solutions with.net Micro Framework Dave Baker Architect Evangelist Microsoft UK Session Objectives The challenge of embedded development How the Microsoft.NET Micro Framework fits in.net Micro Framework Platforms Developing for the.net Micro Framework platform with Visual Studio 2005 Emulators Why you should be writing embedded code Embedded Devices Embedded Devices are tiny platforms Remote Controls Data loggers Device Controllers Single Purpose Device The processor is there just to drive the device High volume/ Low cost No need for an operating System Writing Embedded Code You may be forced to work in C or C++ at a very low level of abstraction You may need to use an ad-hoc collection of tools and device drivers You may need to interact with hardware devices in strange and poorly documented ways You may find it difficult to debug your code when it breaks You may find it hard to emulate the solution You may find it hard to reuse your collections Enter the.net Micro Framework The aim of the.net Micro Framework is to make it as easy to write code for devices as it is for the desktop Write in C# in a managed environment Code against a familiar API Develop and debug in Visual Studio 2005 Use powerful and extensible hardware emulation Desktop developers can easily move into the embedded space Embedded developers can make use of modern language and platform features MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 1
What s the.net Micro Framework? Microsoft.NET on a TINY Footprint device <400 KB of RAM No memory management hardware requirement No Operating System overhead Applications run from Flash memory (EEPOM) Programs run in a managed environment Programmers can use a subset of the full.net Framework What s it for? Intended to power small devices Connected, small, wearable, Integrated, graphical UI, Very low power consumption Not High Performance Not hard real time but useable and useful Wide range of potential applications Sensor nodes, Auxiliary displays, health monitoring, remote controls, data logging, device controls, robotics Because it is easy to create solutions, we see great potential in realising new ideas.net Micro Framework Context How it Works Device Features.NET Micro Framework Connected, Small, Wearable, Graphical UI Footprint ARM 7, ARM 9, No MMU, 250-500KB, Managed Code Windows CE Connected, Graphical UI, Server, Browser, RAS DirectX X86, MIPS, SH4, ARM, with MMU, 12 MB Managed Code Windows XP Embedded PC Class Performance, PC Class Networking Power Very Low Power Low Power Mains Mains X86 Windows Vista PC Class Performance, PC Class Networking X86 Dual Core, 64 Bit, Multi Processor C# source compile to Microsoft Intermediate Language (MSIL) MSIL downloaded in compressed form and interpreted in Micro Framework device From a code perspective it is running in a standard.net assembly Application runs as soon as device is powered up.net Micro Framework Architecture The Missing Operating System Device powered by.net Micro Framework does not have or need an operating system Applications run natively on the hardware using a Bootable Runtime System Simplifies deployment Reduces the demands on the target platform Applications still have access to much of the.net API Provided by the runtime system rather than the operating system MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 2
.NET Framework System.Web Services Description Discovery Protocols Cache UI Controls HTML Web Session state System.Windows.Forms System.Drawing Drawing 2D Imaging Component model Printing.NET Compact Framework System.Web Services Description Discovery Protocols Cache UI Controls HTML Web Session state System.Windows.Forms System.Drawing Drawing 2D Imaging Component model Printing System.Data ADO.NET SQL Client SQL ServerCE System.XML XML Document Xslt/XPath Reader/writers System.Data ADO.NET SQL Client SQL ServerCE System.XML XML Document Xslt/XPath Reader/writers System Collections Globalization IO Net Reflection Service process Diagnostics Threading Runtime Interop Remoting System Collections Globalization IO Net Reflection Service process Diagnostics Threading Runtime Interop Remoting.NET Micro Framework System.Web Services Description Discovery Protocols Cache System.Data ADO.NET System Collections Globalization UI Controls HTML Web Session state SQL Client SQL ServerCE IO Net Reflection System.Windows.Forms System.Drawing Drawing 2D Imaging System.XML XML Document Xslt/XPath Service process Diagnostics Threading Component model Printing Reader/writers Runtime Interop Remoting Platforms Freescale imxs Development Kit Fully Featured Device ARM920T core 32MB SDRAM 8MB Burst Flash I2C, RS232, SSI 2.5 inch QVGA screen 11 keys Windows Sideshow development platform Great for Prototyping Platforms Digi Connect ME Small embedded device ARM NS7520 core 8MB RAM 2/4 MB Flash Network connected Network powered GPIO/ Serial Can be used for embedded control and data logging Building Your Own Platform Porting the.net Micro Framework to your platform is generally a simple exercise Integration can be performed at either the PAL (Platform Adaptation Layer) or the HAL (Hardware Adaptation Layer) Depends on Target Less than 3 weeks. Contact.NET Micro Framework team directly if you wish to do this. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 3
.NET Micro Framework Application Development All components are written in managed code Ease of development with C# Fully integrated into Visual Studio Debugging support UI design tools Access to a subset of the full desktop.net Framework libraries Managed code development story for both the application and the emulator. Hardware and C# Code If you write embedded code you will be familiar with the issues involved with coding for specific hardware Strange bit masks Arcane values for control registers Bind software to physical memory locations.net Micro Framework abstracts you away from this Interact with the hardware using an object model and standard C# constructions such as delegates Reading an Input Pin Objects and Hardware // Map the pin to the software Cpu.Pin switchpin = Cpu.Pin.GPIO_Pin2; // Create a port connected to a pin InputPort switchinput = new InputPort( switchpin, //pin false, //no glitch filter Port.ResistorMode.PullUp); // Use the pin If (switchinput.read()) Debug.Print( input high ); Input and Output connections are managed by objects The output port object provides a method you can use to set the state of the pin You can also create ports which generate interrupts when they are triggered These make use of delegates to dispatch the interrupt event Built in hardware abstractions for RS232, I2C, SPI, LCD Graphical displays The.NET Micro Framework has comprehensive graphical output for driving device displays The facilities are provided at two levels: Bitmap class provides a range of simple drawing facilities (shapes, images, text) Windows Presentation Foundation (WPF) set of display elements that can be used to create complex displays. The default template uses a standard WinForm Persistent Storage.NET Micro Framework v2.0 does not have a file system Store information in memory using standard.net objects and value types To persist these objects and values between sessions, Microsoft.SPOT.ExtendedWeakReference will prioritize which data to keep around Priority levels range from throw this away anytime to keep this around no matter what ID values act as filenames, allowing you to persist these values between system reboots MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 4
x86 HAL / PAL TinyCLR (x86) HAL / PAL TinyCLR Code Challenges Power Requirements.NET Framework, developers often create a low-cpuusage loop using System.Threading.Thread.Sleep( ) to wait for an asynchronous condition or for a callback.net Micro Framework and battery-powered devices, need to use callbacks and interrupt-based events Only execute code when necessary Debugging and Performance Tuning Similar to headless Windows CE applications, may not have a graphics display to write out code run-time intervals Debug.Print uses approx. 30ms of CPU time to execute. Write out performance measurements but only aggregate statistics (or subtract the Debug.Print execution time) The Emulator Ease of development Parallel hardware and software development Develop application when hardware is limited and/or non-existent Easier and faster deployment We need to emulate the environment The core chipset we emulate is often just a controller for various other devices connected to the system We provide all the basic components out of the box GPIO, Serial Ports, SPI, I2C, Display etc Emulator Architecture Versus Actual Hardware Microsoft.SPOT.Emulator.dll EmulatorComponents GpioPort GpioPort EmulatorNative.dll Microsoft.SPOT.Hardware.pe Microsoft.SPOT.Native.pe Microsoft.SPOT.Graphics.pe MFApplication.pe Microsoft.SPOT.Hardware.pe Microsoft.SPOT.Native.pe Microsoft.SPOT.Graphics.pe MFApplication.pe Engine MyEmulator.exe UI my.config MyComponent The Emulator Emulation at the PAL level. An x86 version of PAL / HAL is used for the emulator. Above PAL, the emulator is running the same code (our CLR libraries and the applications) built for the devices The CLR are recompiled to run in Windows The same Micro Framework applications run on both PAL and HAL development cannot be tested on the emulator. PAL / HAL not needed for application development Extending the Emulator Building a custom emulator All this is done in C# by extending the existing emulator and component classes in the project Mainly consists of editing the XML to replicate your board s features: GPIO Pin Assignments, Flash size, Components Using VS forms, you can make your emulator resemble your devkit You can easily build up a library of device and component emulations which can be shared across projects MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 5
Summary Building a Solution using a Custom Emulator. The.NET Micro Framework makes it very easy to target embedded platforms No new skills required Familiar development environment Comprehensive and flexible emulation technology Makes it easy to move from idea to solution quickly and easily Brings desktop development experience to embedded coding Quickly and easily incorporate new technology Developer centre SDK Download, Newsletter, Samples & Tools http://msdn.microsoft.com/embedded/netmf/ Book Embedded Programming with Microsoft.NET Micro Framework, Donald Thompson & Rob Miles. Microsoft Press, ISBN 0-7356-2365-1 Blogs http://blogs.msdn.com/davbaker www.dotnetmicroframework.com conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 6