help...Need to make a wireless robot with cam

[manishrc]

hi all. I'm a beginner.

i need to build a robot driving to wheels.

controlled wirelessly through a laptop

and need to have atleast 4 channels

transmit video from 2 cameras to the laptop(range 100m)

 

presently i'm using arduino to control the robot.

please suggest me what i can use to make those above possible.

i lesser range will do.
thanks

[guncha]

What you need to make above possible is some serious dough for things like:

* onboard computer with decent processing speed (so it can run something like linux) with a USB host
   something along the lines of these two:
   http://www.gumstix.com/store/catalog/product_info.php?products_id=211
   http://www.robotshop.ca/bipom-arm9-gadgetpc-arm-linux-or-debian.html

* two webcams, obviously. spend as much as you care about quality, but make sure that they support
   hardware compression (MJPEG is fine). that means less strain on CPU and smoother playback.

* USB wireless adapter with an external antenna jack, so you can plug in a more powerful antenna and
   extend the usable range. also, I've heard rumors that the new N standard does wonders in this regard.

* USB hub to plug it all in.

* and of course the robot chasis.

After you have all of this, it's a matter of pluging everything together, setting up linux and writing some software to control the robot from the computer. Easy peasy

[Soeren]

Hi,

[...] transmit video from 2 cameras to the laptop(range 100m)

Just use wireless CCTV cams and a receiver at the laptop, then you've got that part covered.
(They can be bought off eBay for cheap).

[Webbot]

You need to think about transmission rates from the cameras back to the PC. This will depend upon the screen resolution.
As a hint: the avrcam using 172x144 resolution takes about 4 seconds to transmit a single frame (with no compression encoding) using 115,200 baud.
You've got 2 cameras.
Thats why most cameras encourage you to do all the image processing on the camera board itself and then just xmit your results over the uart.

[guncha]

As this guy wants to make a peeping robot with stereoscopic vision (meaning, that's what I'd make if I had all the parts) (hehehe, 3D peeping), any camera that connects using UART is out of the question. For live video feeds USB is the only way to go or if you're interested in truly high quality images of neighbors, analog video camera connected to hardware mpeg encoder will give you DVD-like quality (unfortunately, I haven't found any robotics-suitable controllers that had PCI ports for tuner cards).

I actually looked up these things some time ago and Microsoft LifeCam HD looks like a perfect candidate for surveillance robots (is UVC camera so no linux drivers needed + supports hardware mjpeg + HD thing doesn't hurt).

Just my two cents.

[Webbot]

Ok so UART is out. USB may be a goer - but make sure your PC uses USB2.0 at least.

You can reduce comms by compressing the images - but make sure you have something on the pc that can de-compress the images. (I know thats obvious - but worth mentioning),