PL 2303 sous Vista

Une petite info pour faire gagner du temps à d’autres. Le PL-2303 est un convertisseur USB/Série couramment utilisé dans des produits. Et parfois, les drivers fournis ne sont compatible qu’avec Windows XP. Pour Vista, il suffit de prendre les drivers fournis par BAFO Technologies : http://www.bafo.com/menu-support.asp La version actuelle est : http://www.bafo.com/download/2007_download/BF-800/800_Vista%2032_64_v1.6.zip

December 17, 2008 · Florent Clairambault

kernel event to improve network performance on .Net

I have built a simple tcp/udp network server library. I used it on lots of little programs and on one pretty important vehicle tracking server. The first version was using one thread for each connected client. It was working but it consumed a lot of memory. When the server reached something like 3000 simultanneous connections, the kernel was killing it for consuming to much memory. I built a second version which was using network events....

November 2, 2008 · Florent Clairambault

The B.A.T.M.A.N. project

I like meshed network, I recently discovered a pretty interesting project : It’s the B.A.T.M.A.N. project (better approach to mobile ad-hoc networking). It uses and improved the OLSR protocol specifications. Their creator explain their motivations here.(link is broken) You can find some information on the B.A.T.M.A.N. website.

October 11, 2008 · Florent Clairambault

OpenLayers

I took the time to add some OpenLayers support to a web application I’m working on, mainly because I wanted to have OpenStreetMap maps. It can’t replace VirtualEarth or Google Maps because the maps lack a lot of data but unlike GMaps and VirtualEarth it’s free for commercial applications. OpenLayers is a powerful tool. But it’s a little bit ugly (GeoRSS rendering is lame, maps tiles arewere loading in a strange way) and I don’t really like the documentation (if you compare to the Google Maps API pages, it sucks)....

August 11, 2008 · Florent Clairambault

MapPoint WebService authentification with Mono

Recently, I was faced with a little problem. I built a .net program which calls a MapPoint WebService. It worked fine on Windows but failed on Mono/Linux with a “401 Unauthorized” error. As it really made no sense, I decided to listen to the network communication. It did it with wireshark on my computer and tcpdump on the Mono/Linux host. And by looking at the header of the HTTP request, I noticed they were some slight differences....

May 19, 2008 · Florent Clairambault

Etrange MySQL

Aujourd’hui, j’ai décidé d’optimiser une recherche MySQL de recherche par proximité de points spatiaux. En effet, j’avais une requête qui prenait 250 ms en moyenne. Je recherche donc quelques infos et là, bonne surprise je tombe sur un document issu de l’entreprise MySQL sur le sujet. En utilisant l’optimisation qu’ils recommandent (par approximation préalable en un carré de recherche), j’arrive à réduire les requêtes à des temps allant de 5 à 35 ms....

November 30, 2007 · Florent Clairambault