What do the colors on the Particle RGB LED mean?

There are two LEDs on the Core. The big fat one in the middle is a full-color RGB LED that shows you the status of the Core’s internet connection. The other small blue LED is the user LED; it’s hooked up to D7, so when you turn the D7 pin HIGH or LOW, it turns on and off, respectively.

The RGB LED could show the following states:

  • Flashing blue: Listening mode, waiting for network information.
  • Solid blue: Smart Config complete, network information found.
  • Flashing green: Connecting to local Wi-Fi network.
  • Flashing cyan: Connecting to Spark Cloud.
  • High-speed flashing cyan: Spark Cloud handshake.
  • Slow breathing cyan: Successfully connected to Spark Cloud.
  • Flashing yellow: Bootloader mode, waiting for new code via USB or JTAG.
  • White pulse: Start-up, the Core was powered on or reset.
  • Flashing white: Factory Reset initiated.
  • Solid white: Factory Reset complete; rebooting.
  • Flashing magenta: Updating firmware.
  • Solid magenta: May have lost connection to the Spark Cloud. Pressing the Reset (RST) button will attempt the update again.

The RGB LED can also let you know if there were errors in establishing an internet connection. A red LED means an error has occurred. These errors might include:

  • Two red flashes: Connection failure due to bad internet connection. Check your network connection.
  • Three red flashes: The Cloud is inaccessible, but the internet connection is fine. Check our Twitter feed to see if there have been any reported outages; if not, visit our support page for help.
  • Four red flashes: The Cloud was reached but the secure handshake failed. Visit our support page for help.
  • Flashing yellow/red: Bad credentials for the Spark Cloud. Contact the Spark team (hello@spark.io).

##Source: https://docs.particle.io/guide/getting-started/modes/


This topic is now pinned. It will appear at the top of its category until it is either unpinned by a moderator, or the Clear Pin button is pressed.

Best to remove this topic or to add a note at the top the up to date info is at http://docs.spark.io/#leds


I just had an issue with my Spark flashing Yellow/Red. I checked all other systems that we were asked to check in the troubleshooting section, and there were no problems there. I realized, that since I’m not powered to a USB source, just battery pack, the power was dying. Technically, it was having issues connecting to wifi, but the root cause was the battery source. Just throwing this out there because I think, “Check if power supply is adequate” should be added to the checklist on the troubleshooting page.

1 Like

Hey @jsick,

Good point!

Ill try to add that it when I have time to spare or you can send in a PR if you’re comfortable with github :slight_smile:


@BDub, can you help edit the above if you are available? Thanks!

Thanks @psb777 for pointing out

I updated Zach’s post with the info from the Docs. There were two states that were not in the Docs though, White Pulse and High-speed flashing cyan. I also added these to the Docs.

1 Like

Last step in STEP 0: CHECK THE BASICS says:

Make sure your Core has enough power to transmit Wi-Fi signals (300mA in bursts). Try a different power source, or unplug components that draw a lot of power.

This should be good, right?


We can also promote Spark-CLI to resolve yellow/red flashes for bad keys

Hi everyone,

Just a simple question (since this topic is about led):
Is it possible to off the mini blue led, on the top right of the spark core, during deep sleep?

sure! http://docs.spark.io/firmware/#libraries-rgb

@zach, I think this was not what @Leonardo wanted to know.

As I understand it, he is talking about the blue onboard LED connected to D7.
And answering this - although this is not the topic of this thread ;-): “No, there is no way to do this during deep sleep - but there is also no need to switch it off during deep sleep, since it gets switched off anyhow at the very moment the Core enters deep sleep (unless of course, you added some external circuitry that keeps it lit independent of the Cores state ;-))”

@ScruffR Hahaha I don’t know why mine is turned on during deep sleep.

My D7 pin is used to send trig signals for my ultrasound sensor and it is in the off state before it deep sleeps. But when it deep sleeps, the blue light turns on.

Do you think that by putting D7 as a output pin could be the problem?

SInce this thread is mainly meant for the RGB LED color codes, I’ve answered under this new topic

what about slow breathing blue?

mine was doing that for a while, on and off.

Like this crisp list of colors.Wish this page was still updated

Link appears to be dead, or the page was removed/moved.

Thanks for the heads up!

Have you been looking for this?

Thank you @ScruffR. I personally liked the brief list of every color and what they mean. In the past when I looked at the “modes” section I would find that I was getting a color pattern that was not listed. It is possible that the list is better, but I still think the first thing on it should be a short table (of contents) that lists the color pattern and the name of the header that is related.

Hey all–I updated the title and source link just to prevent additional confusion.