HP MSPOT Project

Overview

Raycomm developed a device communication library to enable future application development which utilizes HP’s new MSPOT technology.

Business Case

Solution

Most Pocket PC 2003 SE devices do not have a USB host interface built in by default. Therefore a compact flash based USB host was used which was supplied by RATOC Systems International. By using the drivers supplied with the compact flash device, any PDA running Pocket PC 2003 SE with a compact flash slot can have a USB host interface added.

The MSPOT reader had a set of 9 basic commands that needed to be available for customer applications. It was decided to provide this functionality in a managed C# API. This would make the development of applications using the standard Microsoft Tools a relatively simple operation.

Pocket PC 2003 SE runs a subset of the full .NET framework called the .NET Compact Framework there are significant differences between the two frameworks as regards functions supported however for this project the differences were not significant.

As already discussed the FTDI driver provides a programming interface for the FTDI hardware. In order to use this to communicate with the reader a managed version of the D2XX API had to be developed that supported all the required D2XX APIs. This required extensive use of Managed Interop to pass the data across the managed unmanaged software boundary. Having developed a Managed D2XX it was possible to build a managed API that would mimic the Reader API but at a higher level for the C# and VB.NET programmer.

A .NET Compact Framework 2.0 library was developed using Visual Studio 2005 and following the .NET API design guidelines to provide a consistent user interface. The library also has two sets of custom Exception Classes that allow the reporting of errors caused by the FTDI interface itself and by the Reader. By Breaking down the two sets of errors it is hoped that the user would be able to indentify if the cause was the reader and MSPOT or the USB interface that caused the problem.

The API Library was tested by unit tests and the library conformity was verified by use of FXCop (a tool developed by Microsoft to test their code conforms to the Microsoft Code standard). The combination of these two tools allowed not only the identification of a number of errors in the error management reporting but also identified a few problems in the Reader API itself.

The final library provided was a fully managed C# based library that would allow a customer to quickly develop software to use the MSPOT Reader without having to worry about the requirements of the driver and other hardware.

In addition to the library we also provided a sample application that allowed the exercising of all the API commands and could also act as a demonstration of the possibilities that the MSPOT offered.

Technologies Involved

• PDA
• Windows CE
• Pocket PC 2003 SE
• FTDI USB chip FT245BM
• FTDI USB driver D2XX
• C# .NET Compact Framework 2.0
• FxCop
• HP MSPOT technology

Raycomm are a UK based, custom software and electronics design and development service company creating bespoke electronic products, mobile device software applications, backend web server software and e-commerce database software.