Radio Inteference.

[velocipenguin]

Like the 900 MHz band, the 2.4 GHz band is an unlicensed ISM band because it is prone to interference from common electronic equipment. While 900 MHz may seem rather crowded, the 2.4 GHz band may be even worse. 802.11 wireless networks, cordless phones, microwave ovens, Bluetooth devices, and wireless video transmitters all operate in the 2.4 GHz range. It is very likely - especially in a populated area - that the interference experienced in the 2.4 GHz band would be far worse than that found in the 900 MHz range.

[Tim Skloss]

The 2.4 GHz wireless video works great in my home... if I unplug my 2.4 GHz telephone... and my 802.11b wireless LAN...

But then is is really great! I purchased the 2.4 GHz stereo A/V sender/receiver from:

http://www.discreet-surveillance.com...ansmitter.cfm#

A bit pricey, but very usefull. I use a high-res B/W camera that gives a very sharp picture.

One problem is that wireless LAN, bluetooth and cordless phones operate on 2.4 GHz. However it's not really a problem as long as your reciever is not near one of these devices. If the robot is closer than the interfering device, then you should be fine. It is still sensitive to reflections and when the robot is driving around you will get some breakups. Maybe 1.2 or 1.7 GHz would be better?

My TX operates on 4 channels, 3 of which are in the Amateur Radio band, but with low enough power that you don't need a license. I plan to increase my TX output in the amateur band from 100 mW to 1 W or more, but then it may knock out the wireless LANs at the competition.

For even more fun, I used two servos to control the pan/tilt of the camera with a joystick... We can look down into the robot to see mechanisms working, and then tilt up to see where we are going.

It's a big hit with the students to have a "robot" view. At our open house this weekend we plan to project the "robot cam" up on a wall for the spectators to see... Anything to generate more interest in FIRST.