read mjpg stops updating after error

[sciencewhiz]

The version of read mjpg that is attached to [FRC 2011] Send the Axis Camera Signal Directly to the Dashboard will stop updating the camera image after an error occurs, such as if the camera or robot loses power. I modified the VI so that when an error occurs, the TCP reference is set invalid. This triggers the re-open code that already existed. I don't know if this is doing anything bad (such as leaking references), but it works for me.

[steve_w]

We tried the new version this afternoon and it works very well. When power was cycled on the robot the camera feed started up again. With the camera image now being separated from the cRIO/driverstation data, do you think there is any issue with network traffic from the camera interfering with data between the cRIO and driverstation?

[steve_w]

We were looking at the camera some more today and there was a noticeable delay in the image. When the dashboard runs by itself it's great. But start up the driver station and everything slows down. Have you seen this?

[sciencewhiz]

I did notice processing 320x240 at 30fps (the default setting) used up all of the 2010 classmate's processing power. I reduced it to 10 fps and it worked better. That could be your issue.

It looks like old images will build up in the tcp buffer if you can't read them fast enough, leading to lag. Reducing the framerate would fix that, as would processing on a faster computer.

There is a settings input to the read mjpg vi, which you can use to change the camera's fps.

[43803490]

Hi,

My team stopped using the Classmate and instead we are using my personal computer which has a Intel Core i5 2.4 GHz with 4 GB of RAM and A NVidia graphics card which is decent and I am not sure of the specs (think its a 310M).

Just wondering if someone can tell me the specs of the Classmate from the 2010 season?

BTW. The code works great. Thanks.

Davis catherman

[steve_w]

We also changed the setting to 10 fps and it seems to work better. For the time being we are running the camera through the cRIO which updates fast enough for what we are using it for. But we will probably try going through the router again when we get some time. Thanks for your help.

[sciencewhiz]

It has an Atom N270 @ 1.6ghz.