Optimal board for vision processing

[techhelpbb]

Originally Posted by matan129

So... to summarize, I will always be able to choose NOT to send data over WiFi?
Is it 'safe' to develop a high-res/fps vision system which all its parts are physically on the robot (i.e. the camera and the RPi)? By this question I mean that suddenly in the field I will discover that all the communication actually goes through the field wifi and hence the vision system is unusable (because I have limited WiFi bandwidth - which I never intended to use in the first place).

Even if the D-Link were to repeat the packets you send over the D-Link switch intended only for the wired ports, if the packets are UDP it has no effect on the onboard interconnection. The worst that happens is you hit the field side with UDP and frankly if they are monitoring remotely as they should they can filter that if it really came down to it.

Also you do not need to send much over the D-Link switch unless you are sending video to the driver's station. In fact you can avoid the Ethernet entirely if you use I2C, the digital I/O or something like that.

So you should be good. Just be careful to realize that if you do use Ethernet to do this - you are using some of the bandwidth to the cRIO and RoboRio and if you do this too much you can cause issues. You do not have complete control over what the cRIO/RoboRio does on Ethernet especially when on a regulation FIRST field.

I believe there is a relevant example of what I mean in the Einstein report from years past.

Originally Posted by Joe Ross

Do you have any evidence of this? Bridge mode does not mean that the D-Link acts as a hub and blasts data anywhere. It still has an internal switch and will only send the data to the appropriate port. If both connections are Ethernet, it won't send the data through WiFi. The only exception is broadcast packets.

Yes a properly working ARP table in a switch should work that way.

D-Link has had issues with this in the past. Hence they deprecated the bridge feature from the DIR-655.

There are hints to this floating around like this:
http://forums.dlink.com/index.php?topic=4542.0

Also this (odd is it not that the described broadcast does not pass....)
http://forums.dlink.com/index.php?to..._next=next#new