Outdoor led sign/score board/display - Page 1
Forum section: electronics / projects

author: Milentije
author_rank: Contributor
timestamp: November 20, 2014, 01:41:02 pm
content: Hi to all!This is my first topic on the EEVB forum, and I am looking for help.(If I posted in the wrong section please let me now)I have to make an LED score board that will be used outdoor. I already made one but I am not satisfied with "performance" of the display. The main problem is visibility under the direct sun.I am looking for LEDs that are bright enough to be visible in mentioned situation (big viewing angle is also important).At the moment I am reading datasheet of CREE Screenmaster series of LEDs (for examplehttp://www.cree.com/LED-Components-and-Modules/Products/High-Brightness/4mm-Oval-P2/Screen-Master-4mm-Oval-RGB). Is there anybody that already tried something similar or exact the same LEDs?In attachment you can see one of my tries. Its visible if you shade it somehow, but if its turned against direct sun its unusable...Main question is: Which LED should I use? (I know that the LED is not the only thing and that I should put some kind of anti glare barrier in front of the display, but for now I am looking just for LEDs.)I am asking this because I am living in s***y country so I have to order everything from outside, but I don't have enough time to wait and money to pay all that shipping and customs costs.Thanks in advance!Best regards,M.

author: jolshefsky
author_rank: Regular Contributor
timestamp: November 20, 2014, 01:57:50 pm
content: I think your issue is more mechanical than electrical. If you make your black higher contrast with a low-reflectivity glass and a matte black interior, you can gain the contrast you're looking for.

author: Milentije
author_rank: Contributor
timestamp: November 20, 2014, 02:13:32 pm
content: Thank you for the replay!Yes, you are absolutely right. One of the problems is the casing itself (glossy glass, not that good interior and other things). Definitely, I'll change it in the next revision. But, I am looking for some ultra-mega-gigahigh brightness LEDs to also improve that part of the story.

author: bookaboo
author_rank: Frequent Contributor
timestamp: November 20, 2014, 02:57:39 pm
content: I had success on a similar project using thesehttp://www.rapidonline.com/electronic-components/kingbright-l-2523surc-e-5mm-hyper-red-led-2500mcd-72-8948

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 20, 2014, 03:15:45 pm
content: Take a look at Chinese LED signage panels - they are typically cheaper than you can buy the LEDs for.The white ones are very bright, and have shades to improve readability in sunlight.e.g.http://www.aliexpress.com/item/P10-Outdoor-White-color-LED-display-module-320-160mm-32-16-pixels-waterproof-high-brightness-for/1644825410.html

author: Milentije
author_rank: Contributor
timestamp: November 20, 2014, 03:31:30 pm
content: Thank you mike and bookaboo!I am not able to buy these LED panels from aliexpress because of the "Can not deliver to ..." problem. Like I am living on Mars.I got few instructions from bookaboo.As it seems everything is in 2000+ mcd narrow angle leds and good casing (anti glare glass, matte black interior finish,...).EDIT:This is what I am looking for to make.I am curious to know which leds are used.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 20, 2014, 04:01:54 pm
content: Quote from: Milentije on November 20, 2014, 03:31:30 pmThere are plenty of sellers - should be able to find some somewhere. probably some on ebay as well

author: Milentije
author_rank: Contributor
timestamp: June 19, 2015, 12:20:04 pm
content: Here I am after more than 6 months later.Thank you all for your suggestions and help.LEDs used here are CREE C566C-GFN-CX0Y0782. Diodes are driven with ~10 mA and contrast is good.In front of LEDs there is an plexiglass sheet with dark foil.

author: bookaboo
author_rank: Frequent Contributor
timestamp: June 19, 2015, 01:28:29 pm
content: Excellent project, good to hear you found a solution. For readers wondering whats being scored there it's parachute accuracy, the target pad has a 2cm "bullseye" that the parachutist is trying to hit with his heel!!!

author: Milentije
author_rank: Contributor
timestamp: June 19, 2015, 03:47:05 pm
content: Thank you bookaboo!For those who don't know what you were talking about here are the pics.That's the pad that skydiver has to hit in a center. Center has 2 or 3 cm in diameter (2 versions, 2 cm is used today). Every centimeter from the center is 1 negative score. Goal is to collect as little negative scores as you can. Maximum negative score is 16 (16 centimeters from the center).

author: IconicPCB
author_rank: Super Contributor
timestamp: June 19, 2015, 10:40:24 pm
content: E crni Milentije..I get my LEDs from a Chinese manufacturer directly and typically purchase them in thousands. There is no problem in having them shipped to Your address as Alibaba seem to imply.I had cause to send a couple thousand LEDs to a place very dear to me ( respect Yourself ). No problems. Paid for goods.. paid for DHL shipping ..paid customs fees and Voila.. LEDs were delivered.If You want to I can provide You with the contact details of my source in China. In lots of a thousand pieces I pay approximately six US cents a piece. This does not mean You will get the same price I do as I have been their customer for a number of years.

author: Helix70
author_rank: Unknown
timestamp: June 20, 2015, 02:30:55 pm
content: You might improve your visibilty with a PWM LED Driver such as those from macroblock (drive LEDs at more than 10mA and PWM them - looks brighter for same average current), and you can try shadow boards (black matt panel with holes in it) in front of the LEDs (Of course, you can't have everything, so visibilty angle is reduced).Add a light sensor and microcontroller to adjust LED PWM for the incident and backlit sunlight.

author: Milentije
author_rank: Contributor
timestamp: June 20, 2015, 05:28:09 pm
content: Quote from: IconicPCB on June 19, 2015, 10:40:24 pmNice.Will continue conversation via PM.Quote from: Helix70 on June 20, 2015, 02:30:55 pmThere are some improvements to be implemented in next revision. One of them is better way of driving the LEDs.Thank you for suggestion.