Print

Print


We, too, had a problem with our EV3 color sensor seeing the green on the mat. It began to detect green when we elevated the color sensor to about 1 cm from the mat. 

-Marvin

On Oct 7, 2014, at 7:13 PM, Fredrik Nyman <[log in to unmask]> wrote:

TL;DR: It is complicated.  

Both the EV3 and the NXT sensors are sensitive to light conditions.  An added complication is that both are calibrated to recognize brick colors, and that colors printed on the play field are perceived differently.  Another complication is that the NXT and EV3 color sensors are different, using different color LEDs for illumination so that they get very different results for Color Sensor > Compare > Reflected Light Intensity, particularly for red. 

If the light is just right,Color Sensor > Compare > Color will work nicely.  And if it isn't, it won't.

If you want a robust solution:
1. Use the yellow Color Sensor > Calibrate > Maximum and > Minimum blocks to calibrate for black and white at the tournament
2. Use Color Sensor > Compare > Reflected Light Intensity instead of Color Sensor > Compare > Color; it is a bit less sensitive to light conditions.


On Tue, Oct 7, 2014 at 6:57 PM, Frank Levine <[log in to unmask]> wrote:
I'm interested in the color detection answer... we're having a heck of a time getting it to detect the green lines, regardless of the lighting.

Thanks,
Frank

On Tue, Oct 7, 2014 at 4:10 PM, Molina, Katherine <[log in to unmask]> wrote:
Hello everyone,

Please excuse my ignorance for the following questions.

Can someone please tell me if there will be fluorescent tube lighting made to specs above the table at the tournament? I assume so but just thought I'd check.

For those using the EV3, have you noticed a difference in color detection with the light on or off? IOW does the difference in ambient lighting make a huge difference for the EV3 when it's detecting colors?

Thanks so much,
Kathy Molina
Team: Verbum Sap Sat

From: First Lego League in Virginia and DC [[log in to unmask]] on behalf of Phil Smith III [[log in to unmask]]
Sent: Monday, September 22, 2014 9:33 AM
To: [log in to unmask]
Subject: Re: [VADCFLL-L] Project presentation tools & aids

I wouldn’t count on anything in particular. Usually there are desks and chairs, but you never know.

 

From: First Lego League in Virginia and DC [mailto:[log in to unmask]] On Behalf Of Skip Morrow
Sent: Monday, September 22, 2014 9:18 AM
To: [log in to unmask]
Subject: [VADCFLL-L] Project presentation tools & aids

 

When we go to the tournament, what will be available in the presentation room for my team to use? Posterboard easel? Desk or table? Chairs? Or should we literally expect nothing more than an empty room?


.


To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-announcements-l.html to subscribe.


To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-announcements-l.html to subscribe.

To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-announcements-l.html to subscribe.


To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-announcements-l.html to subscribe.


To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-announcements-l.html to subscribe.


To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list".
VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-announcements-l.html to subscribe.