End 1998 I was involved in a project where Bluetooth was used for short-range communication. While the development activities in the project continued, no real visible results were produced and were not really expected until the final phase of the project. During the project our understanding of this technology increased, and I started to look for a way to make the possibilities of Bluetooth 'visible'.
Somewhere in 1999 I became aware of the possibilities for accessories of Ericsson phones (now SonyEricsson) to be controlled from the phone's menu-system. It appeared that dynamically menu-entries could be inserted, and user selection caused events... interesting. Some tests using prototyping software showed that the dynamic menu capability was also available through a Bluetooth connection...
The first attempt to use the dynamic menu feature on the phone made it possible to manipulate a picture of a lamp displayed on the PC. It was possible to switch it on and off. When that worked fairly stable I started to wonder what I really needed, remote control over Bluetooth on a PC. Manipulation of a PowerPoint presentation was obvious.
The first version was build directly on top of a development kit for DigiAnswer Bluetooth PCMCIA cards. The next on a Bluetooth Development kit for Ericsson modules. Both required quite some software to be installed, i.e.. the driver software was needed as well.
Somewhere in 2000 Bluetooth devices appeared where the vendor provided software also emulated COM-ports on the PC. This made it possible to restart the development of the tool, now towards COM-ports as interface to the Bluetooth connection to the phone. The advantage was also that I could do the major part of the testing via a serial cable.
Interfacing serial ports on a Windows machine does provide its challenges. I use Delphi as development environment and it appeared that there is some difference in behaviour in the (freeware) components I used for the serial communication. I have not been able to pinpoint the exact location of the problem, some mysterious inside Windows behaviour could be the cause as well. What happened was that I did not receive a 'character in input buffer' event in some cases, which is annoying as then the tool would 'hang'. The occurrence surfaced most often during a PowerPoint presentation where the slides contained big graphics, which resulted in extensive harddisk access. It seems somewhere there is an execution sequence issue during high IO-load. Anyway at version 3.4 I did extensive testing on a number of different serial libraries, the one I use now is quite straightforward and does not provide some of the features of others (Serial NG version2 of www.domis.de). But it works.