need a help to drive my stepper motor

hello frds

i am santosh of final year ece.

i am building robot on my own at my home and the name is obstacle avoidances robot using ir sensors.

i need help on interfacing stepper motor or dc motor to 89c51.

and also on ir sensors. as i dont have any idea that ir signals are reflected
from obstacle.

assuming that his 89c51 is a controller chip i suggest you to build/buy a H-bridge system (search for it on the web). then you can drive CCD motors that have more unf (power) and are easyer for you to controll as you have no xp. if you want to get feedback use the same system as bullet mouses (the old ones nonoptical). the wheel with holes and the optical system.

as for the IR sensors i suggest you to buy a sharp IR sensor. it has good range (30cm) and are easy to interface via digital or analog communication. but is fou want to make them yourself you must build a IR emitter using PWM to adjust power and get it to the max and to modulate the IR beam to extract it from the amicient IR lights. Also you need an IR sensor that maches your modulation (38kHz or whatever). Those are 3 legged IR sensors thet are also used in TVs and in all IR remote controlled applications.

hope it helps.

use uln2803 driver ic to drive steppers