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 strand.
  • Check power supply polarity and voltage. Are + and - swapped? If you have a multimeter, confirm 5V DC output (±10%) from the power supply.
  • Are the power wires at the opposite end of the strand insulated or trimmed? They should not be left exposed where they might make contact with metal, or each other.
  • 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 strand.
  • 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 LPD6803() constructor match the number of LEDs in the strand (both will be 20 if using the strandtest example and a single strand of LEDs).
  • There may be a dodgy connection inside the first bad pixel or the one immediately before it. You can cut out the offending pixel(s) and join the two sub-strands.

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 strand from one end. Voltage will drop along the length of the strand and the furthest pixels will “brown out.” Connect power to every 20 pixel strand.

Sketch will not compile: error message is “ LPD6803 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 LPD6803, 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.
This guide was first published on Jul 29, 2012. It was last updated on Jul 29, 2012. This page (Troubleshooting) was last updated on May 07, 2019.