Photon suddenly starts flashing green

I’m testing the reliability of the photon working for lengthy times. I left it today plugged in the USB and normally flashing cyan, then after i got back home it was suddently flashing green constantly and not going to cyan at all. I restarted it … flashed green then cyan then it went on to breathing cyan. 10 seconds later started flashing green again.

No matter how many times i restart it it does the same.

I know there’s a similar thread here : Flashing green at random times after breathing cyan , this is 2 years old. I’m running version 0.4.9 (latest as of Feb 16’).

Q1 : What is going on :smile:
Q2 : I’m planning in the coming period to launch the photon as part of a product for customers, is this a known reliability issue with the photon? i’m not running any delays (as suggested on the thread i posted above) and is there a Software facility available to fix this so that the user can fix it from our mobile app?

Help is really appreciated here guys many thanks :smiley:

If it always stops about 10sec after starting to breathe, it’s most likely your code blocking for more than 10sec.

Showing your code would save us having to guess :wink:


(Same team here) It doesn’t always stop, I think it is WiFi related (maybe encryption type?). We’re using WPA2-PSK.

Is there a feasible software solution that would force the Photon to restart in this case?

I’d say it’s not WPA2 related - experience shows it’s most the time code related.

Hence I repeat

No code - no help

Hi @she7ta,

The other solution for this is to use the “Hardware WatchDog” to hard reset your device if it stops responding after some period of time. But that won’t fix your issue if your code is hard-blocking / causing the device to drop offline, etc.

If you want, I’d recommend emailing who can help coordinate an official firmware review if you’re looking for help there.


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Ups, sorry folks, @she7ta and I carried on via PM on this.
Should have mentioned and reminds me to follow up on it.

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I’d like to add an observation of my own. I have tinker flashed on my photon, i have it on a board with a triac that is switching my home lights and working fine. I just open tinker, trigger D4 and I get lights on/off. A couple of days ago, i woke up three times at night randomly to see the photon blinking green (attempting to authenticate).

I guess having tinker on boards eliminates the possibility that this is a SW related issue on my (our) side. I wanted to know from the Seniors here what are the scenarios that would (suddenly) trigger the photon to re-authenticate or search for a wireless network.

Restarting the router does help (because sometimes it just keeps searching non-stop and restarting it doesn’t help).

The solution to automatically restart when there is no connection is ok , but our product based on the photon is designed so that it would remain working without an internet connection (a push button for triggering the lights), we did this via System Thread APIs, Restarting the photon would mess up this scenario.

One possible cause for a reconnect might be end of leastime of the IP with a failing re-lease due to other devices acquiring the IP and/or the router running out of free DHCP IPs.

But this is only one of the possible reasons.

In my home network (various subnets) I sometimes have the issue that one of the routers just looses internet connection for unknown reasons, inevitably causing the connected Particles to go flashing green.
In such cases I could just wait a few minutes for the router to recover and the Particles (and other devices) will regain internet connection, but sometimes I do have to restart the router - “radio silence” during this time seems to help the router to calm down tho’.
For me this is only a router problem I just can’t get solved and has nothing to do with the Particles.

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