Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: HDL_CinC_Dragon on August 26, 2007, 12:34:18 AM
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Im pretty sure this one is fine but I want a second opinion or more since I dont have room to make mistakes based on my budget...
Would this be a good selection for a range finder on my $50 robot?
http://www.acroname.com/robotics/parts/R48-IR12.html
10cm(~4") to 80cm(~30") range which is awesome and all that good stuff...
and only like 15 bucks...
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Servo city is out of stock on the HS-311's! NOES!!!11!
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actually I'd use this one:
http://www.acroname.com/robotics/parts/R144-GP2Y0A02YK.html
It's cheaper and has better range...
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Why not this one, for $8.25? I definitely recommend this site, smaller prices and lots of goodies!
http://www.junun.org/MarkIII/Info.jsp?item=73 (http://www.junun.org/MarkIII/Info.jsp?item=73)
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whatever you do, dont buy a digital output one. I nearly made this mistake it was lucky i read the datasheet before placing an order. The digital ones only emit a single bit high/low output and so are preset to only go high at a specific range such as 30cm, anything outside of that range doesnt register, although you can supposedly change the preset range it still limits you to a set distance which is only really useful for something like a bump sensor
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Thanks for the site ro-bot-x.
whatever you do, dont buy a digital output one. I nearly made this mistake it was lucky i read the datasheet before placing an order. The digital ones only emit a single bit high/low output and so are preset to only go high at a specific range such as 30cm, anything outside of that range doesnt register, although you can supposedly change the preset range it still limits you to a set distance which is only really useful for something like a bump sensor
That's not true, a digital sensor just outputs an 8 bit binairy number that tells you the distance.
There are sensors with a fixed distance like you described, and you're right that they're not usefull for our cause. So read the details everybody! :)
But what I'm saying is these "bad" sensors aren't neccesairly digital ones, or vice versa
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actually I'd use this one:
http://www.acroname.com/robotics/parts/R144-GP2Y0A02YK.html
It's cheaper and has better range...
hmm good point, I will consider this one.
Why not this one, for $8.25? I definitely recommend this site, smaller prices and lots of goodies!
http://www.junun.org/MarkIII/Info.jsp?item=73 (http://www.junun.org/MarkIII/Info.jsp?item=73)
ehhhh Id rather not have the wider viewing angle, that way I think I can more easily control what my robot is looking at. Thanks for the suggestion though.
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Servo city is out of stock on the HS-311's! NOES!!!11!
try towerhobbies.com
ehhhh Id rather not have the wider viewing angle, that way I think I can more easily control what my robot is looking at.
there are advantages to a wider beam. for example, the Stampy algorithm will work better with a wider beam. its always an accuracy vs speed problem, and in some cases speed is better than accuracy . . . if only they sold IR sensors with the range and beam size of sonar . . .
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So ill get more speed out of the of the sensor at the cost of accuracy? How much accuracy would I be losing? along the range of 5-8cm?
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TowerHobbies.com had it :) thanks admin!
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I you're going to rotate your IR sharp using a servo, It's better to have higher speed than accuracy.
It doesn't matter if you have 5cm errors, all you wan't is to have the robot go the way with no readings.
(In most cases ofcourse :) )
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Well I also want to be able to have him make a map of everything he sees but thats after I get him working completely in the first place...
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I'd go with the GP2D12 or the GP2Y0A21YK (I've use them on 2 robots now, they do alright).
You don't want to use anything that has a huge blind spot that gives false readings so I'd stay away from the 20cm to 150cm sensor unless you are going to back it up with another sensor.
my $0.02
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ive decided to go with the http://www.acroname.com/robotics/parts/R144-GP2Y0A02YK.html
im gunna order it soon.
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http://www.junun.org/MarkIII/Info.jsp?item=17 (http://www.junun.org/MarkIII/Info.jsp?item=17)
Same thing, 2 dollars less.
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Thanks RobotX
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You're wellcome. When I link a page, make sure you visit all the site! Like I said in the previous post, they have good parts with good prices and they are reliable.
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I'd go with the GP2D12 or the GP2Y0A21YK (I've use them on 2 robots now, they do alright).
You don't want to use anything that has a huge blind spot that gives false readings so I'd stay away from the 20cm to 150cm sensor unless you are going to back it up with another sensor.
my $0.02
Where did you get that from? :)
Who sais that the sharps with a range of 20-150 have a blind spot?
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It's not so much that they have a blind spot but the sensor readings give false distances below 20cm, or so the data sheet says...
Ohh dear... are you being facetious? How helpful! :P
I was just bringing up the fact that under 20cm objects will be closer than they appear. Without more information your robot will assume that the object is getting further and further away as it actually travels closer and closer if it ever get closer than 20cm to an object. But if you're ok with your robot doing that so am I.
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I bought the 10cm to 80cm rangefinder.