ELECINF344/381

Interactive web site of Télécom ParisTech's ELECINF344/ELECINF381 Robotics and Embedded Systems classes (a.k.a. ROSE, 2012 session).

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Rose Ace : My computer is running at 1000rpm – Strikes back

Here is a new version of our experimentation with some points corrected.

First we balanced the blades by putting one battery on each blade.

We had problems to connect in Wifi. Indeed we realized that the channel we chose randomly (the 7th) was the most occupied. We switched on the 4th channel and communication was much easier.

Flx© also eased the experimenting protocol by writing a tiny sh script that kills NetworkManager just after booting.

Then we had problems with our batteries again; tomorrow we will try to feed the board through ball bearings.

But we were able to lauch the experimentation:

We launched a scp of movie from a pc to the board. The transfer rate grew stable to 2.5 MB/s.

Then we started the rotation, the rate dropped to 2 MB/s but then remained stable.

We mesured the rotation speed by recording and analyzing the sound of a paper sheet striking the blade: We were turning at 12 rotations per second so 720 rpm.

 

The first conclusion is that in the worst case, we will be able to transfer informations using WiFi on our blade up to several Mb/s.

 

Now we have to improve the experimentation:

-if we use a scp, the flow may be slowed by other parameters. We are going to try to get a file from the internet.

-we have problems with our batteries so we are going to feed the board with ball bearings (the rotor is connected to the ground).

Sylvain Ract

Possibly related posts:

  1. Rose Ace : My computer is running at 1000rpm
  2. Rose Ace : Architecture choice & distribution of work
  3. ROSE-ACE : First presentation and reflexion about general structure

1 comment to Rose Ace : My computer is running at 1000rpm – Strikes back

  • Why are you using scp to measure Wifi performances ? Why not use nc or something equivalent to avoid eventual compression / decompression / decyphering bottlenecks ?