Video transmission

[abe_xabre]

I am working on a robot which has to send back video images of the view in front of the robot. The requirements are 100ft beyond line of sight.
Any ideas for the same. I have already considered 802.11b but have no good pointers in that direction. Analog and digital solutions both will do since I can change the cam to suit the transmitter needs.

 

[tansis]

Request project overview....
eg: What kind of enviroment will it be operating in ?

In open/rolling terrain line of sight may be obscured and microwave links rendered useless the solution here is to change the line of sight, get the base station antenna higher.

Slow scan video is another approach that would work well , it allows the use of a lower freaquency carrier wave and higher power transmitter would give better signal propogation. The down-side however is the frame rate and extra electronics required.

Alternatively if the rover has a pc on-board, a modem card interfaced to a transciever operating a lower freaquency could well be the best solution.
Even NASA has to put up with slow frame rates.

 

[nettron1000]

Have a look at these:


**broken link removed**

 

[abe_xabre]

Overview and more questions

Sorry guys but was tied up for some time. Had a look at the links you sent. But I need some detailed info on the products, which is not easily available. Additionaly I don't think they ship to India.
The project overview as asked for:
8051-based (MAXIM DS89C420; since it is free ;-))
Tank style drive, self-righting ability, micro-gripper, manual wireless remote PC-based control, video relay, pan/tilt system for camera.
Controller can control the robot to a minimum of 50m with obstacles like walls, floors in between the controller and the robot. The terrain can be:
a)Inside the house
b) Low undulation terrain like lawns, sidewalks etc.
c) Staircase with a riser of not more than 15cm.
Video link is totally separate from the forward path control (PC to robot). I need a system which is somewhat small, allows wireless link, gives output valid for PC (preferably). Low fps will do. But since I don't have to use my robot on Icarus or Mars, 2fps (240X160) would be decent enough.
Does anyone of you have experience about this one: **broken link removed**
Analog solution will also do.
Idea is to push the solution to below $160 inclusive of all taxes, shipment etc. to Ahmedabad, India. If any Indian sources are available, it would be the best possible thing.
Thanks...

 

[tansis]

Bi-Directional 2.4 Ghz link High Power (1 Watt)
http://www.qsl.net/n9zia/wireless/appendixD.html

Good Site with lots of RF related schematics, well worth a visit.
**broken link removed**

Video transmitter circuits are common but most are for analogue - composite signals only, getting this recieved signal onto a pc requires more hardware. I see why you wanted to use an RF USB extender.

 

[abe_xabre]

The sites are good, but is it possible to get something which is like readymade and hence probably more reliable than what I can make? Something on the lines of RF USB or 802.11b???

 

[tansis]

Have been poking around the web to no avail so far.
The problem is any commercial / domestic RF USB system has its power output limited by law. :cry:
Though you may be able improve the performance of a ready built solution, if you come across a circuit for an RF amplifier designed to operate around 2.4 Ghz

 

[jack55]

Wireless camera for mobile robot

I've seen a mobile robot project using Intel8051 microcontroller and a wireless camera at

**broken link removed**

This site have some great video clips too.

 

[mechie]

2.4GHz Video Link

I have some experience of using
**broken link removed**
a 1.2Watt transmitter - I have a very different application but the transmitter has been running for a couple of years now, no problems.
The Tx is about the size of a box of 20 cigarrettes.

A lower power Tx (UK legal limit) claims upto 100m line-of-sight - this Tx is running about 150m through trees and into an attic (with a Yagi aerial at both ends) and still gives a good colour picture.