Troubleshooting

Many support issues arise from eager users getting ahead of themselves, changing the code and wiring before confirming that all the pieces work in the standard configuration. We recommend always starting out with the examples as shown. Use the pinouts and wiring exactly as in the tutorial, and run the stock, unmodified “strandtest” example sketch. Only then should you start switching things around.

Here are the most common issues and solutions…

The pixels are wired and powered exactly as in the tutorial, the sketch compiles and uploads successfully, but nothing happens.

  • Double-check all wiring. Are the clock and data wires swapped? Is ground connected to the Arduino?
  • Confirm the Arduino is connected to the INPUT end of the strip. If your strip came with a plug pre-soldered, there is only a 50/50 chance this is the correct end. Examine the strip closely, and solder wires to the INPUT end if needed.
  • Check power supply polarity and voltage. Are + and - swapped? If you have a multimeter, confirm 5V DC output (±10%) from the power supply.
  • Is the correct board type selected in the Arduino Tools→Board menu?

A few LEDs randomly turn on when power is applied, but then nothing happens.

The power supply is probably OK. Check for any of the following:

  • Double-check all wiring. Are the clock and data wires swapped? Is ground connected to the Arduino?
  • Confirm the Arduino is connected to the INPUT end of the strip. If your strip came with a plug pre-soldered, there is only a 50/50 chance this is the correct end. Examine the strip closely, and solder wires to the INPUT end if needed.
  • Is the correct board type selected in the Arduino Tools→Board menu?
  • Did the strandtest code successfully compile and upload?

Only the first few LEDs respond. The rest remain off or flicker randomly.

  • Confirm that the number of LEDs in the LPD8806() constructor match the number of LEDs in the strip (both will be 32 if using the strandtest example and a single meter of LEDs).
  • Check for conductive detritus that may have gotten into the strip: solder balls, frayed bits of wire, etc.
  • Between each pair of LEDs there’s a small chip. Find the chip corresponding to the first bad LED, and give the strip a firm squeeze here — it may simply be a dodgy connection. Try this with the prior chip as well. If that works, you can either touch up the connections with a soldering iron, cut out the offending section of strip and join the two sub-strips, or arrange for a replacement strip if it’s new.

The LEDs flicker randomly, not the way they’re programmed to.

Are the clock and data wires swapped? Is ground connected to the Arduino?

“White” LEDs are showing pink instead.

  • This can happen when trying to power too long of a strip from one end. Voltage will drop along the length of the strip and the furthest pixels will “brown out.” Connect power every meter.

Sketch will not compile: error message is “LPD8806 does not name a type”

  • Confirm the library is unzipped prior to installation.
  • Confirm the library is properly named and located. The folder should be called LPD8806, and placed inside your personal Documents/Arduino/Libraries folder — not inside the Arduino application folder!
  • After installation, the Arduino IDE needs to be restarted for new libraries to be used.
Last updated on 2015-05-04 at 04.27.56 PM Published on 2012-07-29 at 11.58.38 AM