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DS Misc > wifi Bandwidth, Buffering and a Macbook

#158498 - zrg - Thu Jun 12, 2008 10:31 am

Hi all,

Currently I'm writing on application for the DS, which sends network messages via UDP to a server, which controls a VR simulation. So the DS is some kind of fancy and overly complicated input device, which shold work in realtime (>100 ms delay). All this is part of my study project, which works fine in general, but there are some issues, I haven't gotten around - so I turn to you for help :)

I use the standard socket library, found in devkitpro 21 (the latest release, as I am also using PAlib for the graphics related stuff)

First, my message size is fixed and always 40 bytes, no more, no less, per message I send. Although this doesn't "fill" my sendrate (around 8 kb/s I got while downloading in DSOrganize), I noticed that I have some serious packet loss and buffering - packets arriving 2-3 seconds after I have sent them. The admins at the it dept suggested some buffering in the router etc. Packet loss shouldn't be a problem, as the server I connect to and the DS connect to the same accesspoint.

Now I limited my traffic to around 1 message every 6 frames or 10 messages per second, which solves the problem at my router at home. But at the university I still have this problem. I think because the wifi network is really under heavy load.

After I found an article on this forum, I tried to set up my macbook pro as an accesspoint via network->create network. No security, no WEP password. The ds finds the macbook accesspoint - I checked and set up the connection in dsOrganize. I tried every channel, but my DS doesn't want to connect to my macbook. When I call connectWFC() it just freezes there, blinking and after 15 seconds or so, the timeout comes. Am I doing something wrong? As Im creating a network (accesspoint), I checked the ip address of the device with ifconfig and I'm using this address to connect to from the DS. Is this correct, as I am connecting directly to the 'accesspoint'?

Sorry for the long read, but thank you in advance for any answers the can help me.

Regards, zrg

#158527 - tepples - Thu Jun 12, 2008 10:05 pm

I think some of your confusion relates to misunderstood words. I'll help you clear them:
  • devkitPro doesn't have releases, in the same way that Microsoft doesn't have releases.
  • devkitARM has a release numbered 21, but that's the newest is r23b. I don't know if PAlib has been certified for this release.
  • The sockets are part of the dswifi library, which isn't necessarily tied to any particular devkitARM release.

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