FastLED WS2801 Verification errors and Runtime problems

Hi there,

I have recently purchased a 50pc WS2801 Pixel LED string for a Particle Photon project, but seem to be tripping up at the first hurdle.

Using the FastLED (3.1.5) library I am running the provided GitHub example ‘FirstLight.ino’ (

I have added data and clock as follows:

// Data pin that led data will be written out over
#define DATA_PIN A5

// Clock pin only needed for SPI based chipsets when not using hardware SPI
#define CLOCK_PIN A3

And have uncommented the line:

FastLED.addLeds<WS2801, DATA_PIN, CLOCK_PIN, RGB>(leds, NUM_LEDS);

However this triggered the same issues as [this user] (, I managed to compile this code by following the advice of ‘Jasoncoon’ in the following message. Editing the line to read:

FastLED.addLeds<WS2801, DATA_PIN, CLOCK_PIN>(leds, NUM_LEDS);

Despite this, my LED string still does not function as coded. It is wired as follows:

  • +5v and GND - connected to a separate 5V 2A plug DC socket
  • 3pin JST SM connector from LEDs - connected to the particle photon with Data wire: A5, Clock: A3, GND: Photon GND

Is there a problem with the code, or have a wired something faulty? Thank you in advance!

you might try the digital pins e.g:

#define DATA_PIN D5
#define CLOCK_PIN D6

Hi thanks for the tip, however the real reason was I required the circuit to be globally grounded, i.e. data pins and power all needed to route through the particle’s ground pin.

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