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funkydude
04-18-2005, 08:46 PM
Hi guys, i wanted to ask you people if IR sensors are better than SONAR sensors? The robot is basically a moving robot, which would try interacting with people. I need to do obstacle detection with the sensors... cost isn't a consideration, but ease of programming the sensors is.
Please let me know which of the sensors are better.. and what is a good place to buy it?( like the name of a site)
thanks a ton

funkydude
04-18-2005, 08:49 PM
oops, i forgot to add, i am using a PIC uc to interface the motors, so i can use the printer port/USB or the PIC to interface the sensors

vikas
04-18-2005, 09:40 PM
A sonar based sensor arrangement is always better than ir . Sonar are always better but they are a little expensive .

funkydude
04-18-2005, 11:26 PM
Thanks vikas! Are sonars reliable though? I've seen people having a lot of trouble with sonar.
I forgot to mention that the lighting in the operating environment is uneven, does this make sonars better?
I'd appreciate any tips on interfacing the sensor, and places where i should buy them from.
thanks a ton

happy_99
04-19-2005, 12:33 AM
I suggest SONAR for this application. If you're goin to buy readymade modules check here

www.acroname.com

Regds

happy_99

subot_robot
04-19-2005, 11:27 AM
Hi funkydude,
If you want to consider the IR sensor then u can go for IR distance sensor from Sharp, GP2D12 also available from www.acroname.com. But it has range of 10cm to 80cm where as sonar will have 3 times this range. All u to do is to connect this sensor to A/D port of pic and start reading the voltage which is proprtional to distance. This IR sensor is immune to ambient light and colour of the reflecting surface.

Subot_robot

funkydude
04-20-2005, 08:19 AM
hey, thanks Happy_99 and subot_robot.. i think id buy the IRs subot suggests... just for the record, the IR you were talking about is GP2D02.. just a small typo i guess~
thanks!!

funkydude
04-20-2005, 10:21 AM
Has anyone worked with Sonar's btw.. i just wanted to know what difficulties u face using sonar's.. there's a good deal on sonar -

http://www.parallax.com/detail.asp?product_id=28015

1 sonar for 25 dollars is a steal i think. So now, i am unsure about what to buy.. which is why i'd appreciate every1's feedback on their experiences with working with sensors.
The IR sensors that subot_robot mentioned are pretty good, only thing is that i am a little unsure if the robot can stop in 80cm.This sonar detects to more than 3m
Please let me know guys.. thanks

subot_robot
04-20-2005, 03:59 PM
Hi funkydude,
I was talking about GP2D12 and not GP2D02. Here is the link to that IR sensor.
http://www.acroname.com/robotics/parts/R48-IR12.html
Regarding sonar sensor, you can build one for less than Rs.350.
The costliest thing is 40kHz ultrasonic tx-rx pair which costs around Rs.250 - 320. You have to build a ckt to generate 40kHz voltage for tx and an amplifier and tone decoder for Rx. and it is ready to be interfaced to microcontroller.

Subot_robot

funkydude
04-24-2005, 11:02 AM
thanks man