Not sure if anyone can give me an advice how to fix this.
The servo controller works fine.
However when I send a signal to the controller, my usb camera video feeze.
The usb camera run normal after all the signal has been to the controller.
running on a core2, window XP
using logitech webcam
Can you tell us more about what software you are using to send the command (maybe with source code)? Also, what are you using to watch your webcam?
Sending a single command to your servo controller over the same USB host controller shared by your webcam should only take a minuscule amount of the available resources. I’m confused because just sending a command shouldn’t take a noticeable amount of time, so even if it was affecting communication with your webcam slightly it shouldn’t ‘freeze’.
For example, I run a program that processes 15 frames per second from a USB webcam, and sends 5 byte serial commands after each frame over a Pololu USB to Serial adapter on the same USB host controller (so essentially the same as what you’re trying to do). The serial commands have no effect on the speed of communication with the webcam. I suspect your software is doing something odd, like opening and closing the virtual com port for each command, or trying to continuously transmit commands.
I solve the problem by following your suggestions.
I open and close the serial port each time… that is why it freeze.
Now I only open once… the usb camera does NOT feeze anymore.