Distance Measurment Using Laser Red Pointer

Project Presentation Supervisor: Mr. Tasneem Akhtar Group:

(Q445924)

Khurram Farooq Sajeel Akram M.Asif Haroon

(Q445890) (Q445871)

Faisal Satar Yasir Iftikhar

(Q445855) (Q445841)

Project Name: Distance or Target Measurement using Laser

What is Laser? 

A laser is a device that emits light through a process called stimulated emission.

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The term "laser" is an acronym for Light Amplification by Stimulated Emission of Radiation.

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The power of laser points vary from 1-5 mW.

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Laser light is usually spatially coherent, which means that the light is emitted in a narrow, low-divergence beam.

Block Diagram

Parallel Port

LASER Transmitter And Receiver

Target

System Description 

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We use high speed counter RDTSC (Read-Time Stamp Counter) from the computer processor to calculate the time. This measured time is called time of flight and used in calculation of distance, time divided by 2. RDTSC is a 64 bit counter.

RDTSC How the Time-Stamp Counter Works?  The time-stamp counter is a 64-bit MSR (model specific register) that is incremented every clock cycle.  To access this counter, programmers can use the RDTSC (read time-stamp counter) instruction. This instruction loads the highorder 32 bits of the register into EDX, and the low-order 32 bits into EAX.

Laser Transmitter 

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We build a computer controlled laser. This laser is operated from parallel port. Counter starts when laser ON.

Laser Receiver 

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Laser receiver (photo diode or transistor) use to detect the laser reflection. When reflected beam is received , counter stop.

Time-of-flight 

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Time taken by Laser to hit the Target and reflect back on sensor is called Time of flight. Here, an apparatus sends out a laser beam and measures the time until a reflected portion of the laser is monitored. The time-of-flight method is typically use for large distances such as hundreds of meters or many kilometers.

Distance Calculations Shortest distance measure= frequency (GHz)/speed of light Distance formula: S=V T/2 Here S=Distance V=Velocity T=Time of flight

Schematic Diagram

Algorithm  Main part of our program is in Inline assembly using 32bit assembler ‘YASM’.  Time calculations are in C++ using Turbo C++ software.  Program start , Call RDTSC (timing start) a bit transmit via parallel port with the help of laser pointer , wait for receive, when bit is received via parallel port Call RDTSC (timing stop)  Using this time interval between start and stop time, calculate Distance

Benefits Records Measurements More Accurate Safer Quicker Measuring Long Distance Basic Calculations Built-in Illuminated Versatile Automatic Compact

Thank You Sir