Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.


by adafruit on Tue Dec 13, 2011 11:08 pm

99% of Digital LED strip problems come down to a few very common problems

BEFORE posting, check all of these multiple times.

Strip does not work - Possible causes:
    1. You must connect to the INPUT of the strip, not the OUTPUT. This is incredibly common mistake. It wont work unless data is going into the correct end. Check the tutorial to see how to identify the input side. Just because your cut strip has a connector does NOT mean its an input. Check again!

    2. You must have a common ground between your power supply and the Arduino. If no ground wire connects the strip to the Arduino, it will be flakey and respond strangely, if at all

    3. If you want to light up a lot of LEDs, you need a fairly beefy 5V supply. Make sure its a regulated supply, and you verify that the output is no higher than 6V DC. A good rule of thumb is a max of 2 Amps per meter, with an average draw of about 0.5 - 1 amp depending on use

    4. Check that you did not swap the DATA and CLOCK pins

Strip fails for large number of pixels:
    1. Make sure you have adequate power. Longer strips may require power fed to multiple positions on the strip.

    2. You may be running out of RAM. The library needs RAM to store the state of the pixels. Try reducing the other memory requirements of your program such as strings. Check here for tips: http://itp.nyu.edu/~gpv206/2008/04/making_the_most_of_arduino_mem.html

The tutorial is here: http://www.ladyada.net/products/digital ... index.html

Posts: 12124
Joined: Thu Apr 06, 2006 4:21 pm
Location: nyc

Please be positive and constructive with your questions and comments.