help for project !

[extremeads1]

sir, so far i just have visualised how my project would be,
basically my idea is an IR or Ultrasonic tx will be used to detect the distance from the ground or say distance between the ground and body surface where i'll keep this unit.there will be a fixed reference to this tx say 35cms ,for this distance detected ntn will happen. once the distance drops below 35cms say 30cms then this will be detected and processed by IR Rx & the microcontroller to light up a small bulb say blb1(blb1- below level ) at the same time i want an alarm sounding "WARNING WARNING WARNING" if the distance still drops say to 25cms then the same will happen but this time the blb1 will be turned off and a higher priority blb2 will light up (blb2 - pull up ) and so on,alarm will remain ON .i may use upto 4 such indications but everytime when the distance drops the higher priority indication blbs will be lit up and others will remain off and when the distance becomes normal once again the blb0 (blb0 - normal )will light up (other blbs and alarm off ).
I HAVE TO USE A 8051 or its derivates. so what do you think sir can this project built up . i need help on this

 

[Hero999]

You can buy ultrasonic proximity sensors from RS components that output a voltge between 0 and 10V depending how far an obstacle is all you do is add a PIC with an ADC on and you should be able to figure out the rest for yourself.

 

[napalm]

I hope this helps you
**broken link removed**