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Unread 07-23-2016, 05:20 PM
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Re: 2 Cameras in Java

Quote:
Originally Posted by bdaroz View Post
The problem is that the native WPILib CameraServer class doesn't have a way to stop, or switch, or restart the server instance. You'll need to extend/replace that CameraServer class to make it work. Here's what we ended up doing, albeit a bit quick and dirty:

https://github.com/FRC5881/2016Robot...eraServer.java



Keep in mind that USB is designed to not overdraw current... If you have 500ma of power available and plug in (2) 400ma devices, your hub will only draw a bit over 400ma (a little for itself) and leave the other device unpowered.

You should also be able to plug those cameras into a PC and check the USB device info (lsusb on linux, for example) to see what the current required for each is. After that, some simple math would tell you if you're over committing.

One other question -- are both of these cameras identical?
No, we have a USB hub with a small LCD screen that displays current draw on it, and it looked ok. IIRC the power light was lit for all 3 cameras.

Two of the cameras were identical, one was a different model with a wider field of view. They were all Logitech webcams
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