IR TRANSMITTER AND TSOP1738

I M DOING PROJECT WITH Arduino Duemilanove FOR AUTONOMOUS ROBOT ( OBJECT AVOIDANCE ) USING 2 CONTINUOUS SERVO MOTOR AND 2 IR LED FOR TRANSMISSION AND TSOP 1738 FOR RECEIVING . WHICH PROTOCOL SHOULD I USE OR ANY OTHER SIMPLE METHOD FOR THIS .
PLS SUGGEST ME OR ANY SITE FOR THIS

Well, our Gadget Shield comes with some object detection software that you could use as a starting point.

Here's a video: Rugged Circuits Gadget Shield Object Detection - YouTube

It's a similar setup: IR transmitter and TSOP1838 detector (or similar).

You don't need a "protocol" just to detect objects. Turn on the IR LED at 38 kHz and look for a reflection with the IR detector. Change the duty cycle of the IR LED 38 kHz waveform (see the software) to adjust the distance at which you will detect objects. Too high a duty cycle and you will "blind" the sensor, too low a duty cycle and you won't see any reflections.

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The Arduino Drum Machine: 14-track MIDI drum machine sequencer / groove-box

Check similar project, there's lot of instructions too:

http://luckylarry.co.uk/arduino-projects/obstacle-avoidance-robot-build-your-own-larrybot/