Hello,
I’m new to this forum (but not to robotics). My wife & kids bought me a Wild Thumper for my birthday and I’m having a great time getting to know it. I also have a T’Rex Robot/Motor Controller along with an ODroid-C1 that I’m adding to the system. I’m connecting the ODroid to the T’Rex controller via the I2C interface. Thus far I’ve written a couple of programs to send it commands to turn the motors and wiggle the servos and am getting ready to start hooking up other fun stuff such as ultrasonics, IR detectors, GPS, another Arduino to run the various sensors, etc.
Here is my question about the T’Rex controller… it works great hooked up the usual way via the battery and drives the motors and everything like it should-- but if I just want to use it in a standby capacity (while I write programs, for instance) is it safe to just run it from the USB port? Will it try to pull power to run the motors if I should happen to send it such a command, or is it smart enough to know that it shouldn’t run the motors on just USB power alone? And I guess same question again with respect to the servo power…?
Thanks for creating such a marvelous platform! I’ve been drooling over it for some time now. 
John