other circuits for distance measurement

[superchiku]

can anyone plzz tell abt a schematic that can be used in distance measurement as sonar and sharp ir are not available where i live??

[airman00]

What is your application and also we need more details !

Like what range do you need, what objects are you ranging , your robot setup, etc.

[superchiku]

robot must range between 3cm to 2m i have to use it in a sumobot to find the victim

[Ro-Bot-X]

In a sumo contest you don't need to know the distance to the oponent. All you need to know is what direction the oponent is located. Take a look at the VCR robot, those IR sensors can detect the oponent and give you Left-Center-Right directions. If you need more precision in finding the exact angle the oponent is located, mount only one pair of IR LED and Sensor on a servo and use it as if it were a Sharp sensor (but like a digital On/Off sensor). To narrow the detection angle, use a narrow beam LED and a piece of tubing in front of the Sensor. Then you can use Stampy code for oponent detection.

[superchiku]

yes simple ir can help but still the range will not be much and i need good range

[Pratheek]

If you need good range with ir then use modulated ir and any of the sensors of the TSOP series. You will get good range and your readings will not be affected by ambient light

[superchiku]

TSOP cant be used for distance measurement or is it ? i think they are only used in remotes

if u have any schematic for distance measurement then plzz do post it here

[Ro-Bot-X]

Check out the Parallax BoeBot manual. You will find out how can a sensor like TSOP (they are using a similar sensor made by Panasonic) can be used to find range. The same method I was talking about in my previous message.

[superchiku]

ill check it out then

[Steel_monkey]

TSOP "measurements" are highly affected with color of an obstacle, so black chair will be seen much closer than white fridge door. Freequency sweep will help, but IR receiver works more statistical then linear- at the boundary of sensivity ( object is far ) it will not just stop working, it will rarely "blink" ( I say so because I monitore it's output with LED), so statistical data processing is required for proper analisys. I personally would prefer sonar   

[superchiku]

ill go with ir coz sonar is costly

[Steel_monkey]

I think, nobody stops you from making it yourself.

[superchiku]

well i did some reserach TSOP isnt taht much trustworthy it wont be able to differentiate colors so i have to get a sharp ir for best results