Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: mlkbdk on March 23, 2013, 04:50:47 PM

Title: A good color sensor!
Post by: mlkbdk on March 23, 2013, 04:50:47 PM
Hi everyone!
First of all i'm new here, but as much as i observed, this is a very nice and useful society :)
I need some help about color sensors. I and a couple of friends from university are trying to make our first robot.  We're making a robot which will determine the targets that have different colors and shoot some among them by recognizing the color. It shoots red ones and passes blue for example. We created the shooting system, it works but we couldn't find an adequate color sensor. We need one which can detect the color of an object from approximately 20-30 cm distance. Well, i don't know much about sensors, so let me know if there is one like that or not. Or you can give me another suggestion to acheive my goal. (selecting friends and enemies among targets)
Thanks in advance
Title: Re: A good color sensor!
Post by: waltr on March 23, 2013, 05:54:32 PM
A color camera where you separate the colors is one way to recognize colored objects at a distance.

The low cost color detectors (like what SparkFun sells) need to be close to work. However, it is possible to add a lens that focuses a more distant object onto the sensor. This would be a lower cost and simpler solution but will require a little study on simple optical systems and some experimentation.
Title: Re: A good color sensor!
Post by: jwatte on March 23, 2013, 08:11:21 PM
If you need 30 centimeters distance, then a camera is almost certainly the best way to do that. You can drive a USB webcam ($30 or so) from a Raspberry Pi (another $30 or so) to make your own image recognition system.
Title: Re: A good color sensor!
Post by: kimorobotics on March 24, 2013, 10:05:39 AM
Check out this open source project, this might be what you're looking for

 " The CMUcam open source programmable embedded color vision sensors are low-cost, low-power sensors for mobile robots"

http://cmucam.org/ (http://cmucam.org/)
Title: Re: A good color sensor!
Post by: mlkbdk on March 24, 2013, 11:41:31 AM
Thank you all! That CMUcam v4 is just wonderful but the price is a bit high, though! I'll consider it with friends. I'll let you know when we decide what to do.
Title: Re: A good color sensor!
Post by: jwatte on March 25, 2013, 12:10:56 PM
CMUCam is $100. A Raspberry Pi plus camera is about $60. The RPi would need more programming on your part, though. What is your actual budget?