Devices that fall in this category include the display, touch panel, audio, serial port, printer, keyboard, LED, battery, and PC card socket. The development of the related drivers takes place during the development of the platform itself by the OEM , and the drivers are integrated into the final CE image, which is stored in ROM or flash.
Installable devices are third-party peripherals that can be connected and detached from the platform at any time by the end user. For instance, a bar code reader can be connected to a Windows CE device by means of a cable that connects to the built-in serial port. Third-party vendors who manufacture the installable devices provide the device drivers. Those drivers can be installed at any time in the object store, which is non-volatile RAM, for instance.
Driver model. Each type is described in the following paragraphs. Furthermore, CE drivers are implemented as either static libraries. Windows CE has been designed to directly use built-in devices. These devices are controlled by native drivers, which are intimately linked to Windows CE's core components. For example, the graphics, windowing, and events subsystem GWES module calls specific functions in the display device driver to render images at runtime.
As one might expect, these functions are different from those required in the battery driver. Hence, each native driver must conform to a specific, well-defined interface called the device driver interface DDI. These interfaces are explained in more detail later. Suffice it to say at this point that none of these interfaces can be changed by OEMs and that native drivers must fully support them. Native drivers are built as dynamic-link libraries, with two exceptions: the battery and the LED drivers are built as static libraries linked with the GWES module when a CE image is built because of their small size.
Native drivers are always loaded at boot time. Stream interface drivers all share a common interface. They are mostly used for controlling installable devices a scanner, for example , but a few are used with built-in devices, such as the serial port device driver, because the stream interface is better suited for those devices. Stream interface drivers that control installable devices are typically accessed by applications. For instance, upon connecting a GPS device to the platform, the user will start a GPS-enabled application that will access and use the device.
Microsoft chose to re-use an existing API specifically, the file API to enable the applications to access those drivers, instead of creating a new one. Consequently, stream interface drivers have been designed to expose a device's capabilities to the applications by presenting the device as a special file, which can be opened, read from, written, closed, and so on.
To be easily identified, stream interface drivers follow a unique file naming convention, which is composed of a three-letter prefix such as CAM for camera or BCR for bar code reader , a digit that identifies a specific device when multiple instances are available, and a colon. The three-letter prefix can be any combination of uppercase letters, but it must be unique on a given platform.
When an application opens a file that follows this convention, the file system module recognizes that a driver is being accessed and re-routes subsequent file system calls to the specific driver. In contrast to the native drivers, the stream interface drivers all share a common interface composed of 10 functions, or entry points, within each driver.
These functions, described in Table 1, closely match those found in the file API that are used by the applications. CreateFile combines the ability to create and open files. There is no OpenFile call. CloseHandle is then called to close the handle. An independent hardware vendor has the freedom to adapt these functions to the device's capabilities. The driver documentation becomes crucial for enabling developers to understand how to use the driver when writing applications that access the device.
Stream drivers can be loaded at various points in time. For built-in devices, such as an audio card, stream drivers are loaded at boot time via entries in the Registry.
For detectable devices a serial port implemented on a PC card for instance , the related driver is loaded at detection time, again using entries in the registry. Finally, applications can specifically request a driver to be loaded at run-time, by calling LoadDriver , for instance. Stream drivers are loaded, managed, and unloaded by the device manager module. Stream interface drivers typically rely on native drivers to perform their duties.
For instance, a bar code reader will rely on the serial port driver to physically access the device. In this instance, the bar code reader is called a client driver, and would use the Win32 file API to access the serial driver, the same way an application would. Client drivers are useful because they encapsulate implementation details, such as processing data into a bitmap image, that applications do not have to be concerned about.
The full USB host-side specification is supported on CE, including the various data transfer methods-control, isochronous, interrupt-driven, and bulk. USB drivers can be implemented using three approaches. First, a USB driver can be implemented as a standard stream-interface driver, allowing applications to use the file API to access the device.
NDIS drivers. Only a subset of the original specification, NDIS 4. As a result, miniport drivers are supported, but monolithic and full drivers are not. Fortunately, miniport drivers are largely source-compatible with those on NT. Microsoft provides various NDIS driver samples, and recommends porting an existing NT driver, if one is available, rather than creating one from scratch.
Device driver implementation. Adapting Windows CE to a specific platform is mostly a matter of developing the drivers for the particular devices the board features. The other aspects are to configure, build, and test the Windows CE image itself.
Driver development, as I will explain, consists of implementing interrupt handlers driectly in the kernel and the code that access the devices the drivers themselves. Interrupts are processed in unique fashion in Windows CE, as shown in Figure 1.
The kernel's event handler is the first to catch a raised interrupt. The interrupt, as well as lower priority interrupts, are disabled, but all other interrupts of higher priority remain enabled provided the underlying architecture supports nesting interrupts based on their priorities. The related interrupt service routine ISR is then called. The sole purpose of the ISR is to return a logical identifier to the interrupt service handler ISH in the kernel, but it can implement more functionality if performance is an issue.
Since Windows CE 3. For instance, ISRs that implement critical code that can't be preempted must temporarily disable all interrupts. However, this should be done only to execute a few instructions, since keeping higher-priority interrupts disabled may interfere with the real-time nature of the system more about this later. The kernel uses the returned logical identifier to unblock the related interrupt service thread IST. The IST resides in the driver and implements the core driver's functionality interrupt processing by accessing the hardware as required.
Once the interrupt is processed, the IST signals the end of interrupt and the kernel re-enables the interrupt. Developers can assign one handler per interrupt or one handler for multiple interrupts. NET Framework, with the most commonly used functionality of both included in the Compact version. Most significantly, using Visual Studio. NET, the. NET Compact Framework supports only the development of the client component at the present time.
Programmers using Visual Basic will appreciate the fact that Visual Basic. NET makes liberal use of helper functions that are located in the Microsoft. VisualBasic namespace.
The version that is part of the. NET Compact Framework offers a subset of these functions as well. The functions included in the Microsoft. VisualBasic namespace are considered a core part of the language, and in fact include many of the keywords from previous versions of Visual Basic. And finally, the. NET Compact Framework provides a set of base classes that expose a wide range of functionality. This underlying infrastructure enables you to write applications for.
NET that incorporate multithreading, take advantage of available network resources, and help you work with files. Now that you have an overview of the. The XMLList application demonstrates two key features of the. This is no ordinary list program, though. Not only can lists be created locally on the device as you would expect but the application can also save and retrieve lists from a server via a Web Service.
This feature enables one individual to build a list and store it on a server so that it can be picked up by another individual. Each list, whether it is stored locally or on the server, is stored by persisting XML to a file.
An example of the XML list structure is shown in Figure 1. I'll describe the Web Service first and following that, I'll discuss the client application. One of the great features of the. Starting with only the ASP. NET Web Service project template and adding a few simple functions, I was able to provide capabilities for storage, retrieval, and management of lists by remote clients. NET DataSets, as the examples in this section will show. In my example I could just as easily retrieve data from an enterprise-based server using ADO.
NET and forward that data to a client as a DataSet. The shell of this service was created using the ASP. NET Web Service project template. To this project I added methods to save, load, delete, and list the available lists. I'll describe each of these methods briefly in the following paragraphs. The SaveList method accepts two arguments the name of the list and the contents of the list , which are passed as an ADO.
NET DataSet. The LoadList method accepts a single argument—the name of the list to load. It returns the requested list in an ADO. The MapPath method of the Server object is used to instruct the Web Service to look in its root directory for the list. For simplicity, I elected to store the lists in the same folder as my Web Service. They could easily be moved to another location at a later time. The DeleteList method handles the removal of lists from the server. Within this function, the Kill method of the Microsoft.
VisualBasic namespace is called to perform the file deletion. This function is by far the most complicated of the four functions. To simplify this feature, I use an existing empty XML file with a preconfigured format. The effect of loading this empty list into a DataSet is that the DataSet will be configured with the appropriate list structure.
All that is left to do is to use the Dir method of the Microsoft. VisualBasic namespace in order to load the list of available files, just as you would have used the Dir function in earlier versions of Visual Basic.
A variable number of repetitive calls are made to this method until all of the list file names have been loaded into the DataSet, as you can see in Figure 2. Accessing your Web Service from Internet Explorer enables you to quickly verify the functionality of your service. NET: the functionality provided through the. NET Compact Framework and the similarity between developing desktop or server applications and creating applications for the Pocket PC.
Figure 5 Usage Mode. With the exception of the testing process, developing applications that target the Pocket PC is very similar to creating Windows-based applications. The code used to build the XMLList client could be used as is to create a desktop version of the client. In this section I'll describe the templates, tools, and controls that are available for developing applications that run on the client. NET New Project dialog. Four templates are added to the Visual Basic Projects folder.
Numerous security enhancements have been made, authentication mechanisms, etc…. You want to make sure you have other security measures in place to mitigate any security concerns that could arise from having an active XP OS running on the network. If anyone else has a better solution or can comment further on this, please do! I searched in the Internet how to access a shared folder from Windows CE 5. We have many Windows CE 5. Units that we have right now it a system that control tank of oil.
I contacted the company GE and spoke with their engineers. They said that it will take months to upgrade the firmware and even that not sure that will work.
They also said to change the unit with newer version that can accept USB so we will be able to upload the file manually. That is crazy just for 1 problem.
In the past, when we had to update the system, we must plug it directly using a serial DB25 cable to DB9. Once that is done, everything works. This is the security that will allow you to access the server. Make sure this account easiest on the shared server. To enter account there should be an icon in control panel owner and click on network ID to enter the information.
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