communication between two robots

[gaurav.p]

how can i implement this function where one robot instructs the other partner to start.
the implementation should be easy( i hope ).

-gaurav

[SmAsH]

how far are they?

[Tomas]

bluetooth should be simple enough.

[SmAsH]

but expensive! use ir dude for short distances of coarse...

[gaurav.p]

the area of communication is small indeed (80*80cm).i wish i could communicate using bluetooth but they r expensive .how to communicate using Ir
,can u give me  idea or a sort of tutorial .

thanx in advance,

-gaurav

[wil.hamilton]

you could always use wifi, you can buy transmitters/recievers for 4USD each at sparkfun.com
or use something like the xbee

[Razor Concepts]

Multiple RF transmitters from sparkfun will interfere with each other, so you could only have a max of two in the same vicitnity (the two different frequencies).

IR would be the cheapest way.

[gaurav.p]

the problem is how can i use a ir receiver and transmitter to activate the power of the second robot.

-gaurav

PS-how to make two robots cooperate with each other using any sort of communication without any interference of the user any anything else(any medium of communication)?

[wil.hamilton]

you would have to have the robot in a "low power" mode where you can jsut monitor the ir or whatever medium of communication

[Razor Concepts]

Magnet on one robot and a reed switch on the other... after the other robot turns on, it retains power to itself with a mosfet? Kind of inefficient though 

[SmAsH]

i would second the low power option... although this would still draw power...
you would have another small mcu (8pin dip) that moniters the ir receiver and sets a transistor closed which controls the power supply?

[wil.hamilton]

i would use  a normally closed mosfet, so it doesnt draw power to keep the rest of the robot "off"

you have a small mcu running off your main power supply monitoring your reciever, then when it recieves a turn on notice, it puts power to the mosfet, opening it, turning the main bot on,  it could also then be used to turn the bot off

should be rather simple, (i might have to build something like that someday, lol)

[sonictj]

I had a friend that created a swarm of robots that communicated over xbee.  They taught eachother to tango lol.

here is the vid

[youtube]IHTA5ldU5sY[/youtube]

[gaurav.p]

gr8 video sonic and i hope(sure) wi,l u would make this bot one day.i m unknown about mosfet so presently i m studying that then i will approach if i have any doubt.ya can i use xbee modules to communicate between each other what is the procedure or any tutorial (i hear xbee is a very large platform so i can easily take help in it and it is often used in many projects).

-gaurav