P1, Slow Cyan Flash, Fast Cyan Flash, Single Red Flash, Repeat

Hi everyone,

We have a board with a P1 on it (no USB available, but we can SWD onto it), and whilst we have been able to connect it to WiFi, it now goes into a cycle of:
Slow Cyan Flash
Fast Cyan Flash
One Red Flash
…and repeat.

EVER so occasionally I have managed to get it online, breathing cyan.

Any pointers?

Can you flash the tinker app and see if it still happens?

Ok, I reflashed Tinker, and it still exhibits the same behaviour. I then reflashed the system firmware (0.6.2), and also then reflashed tinker. Still the same unfortunately.

An additional note: it stuggles to get online, after a couple of minutes it MIGHT get online, but will then drop off after a couple of minutes, and then struggle to reconnect again (Cyan fast flash). If that extra detail helps.

Can you place it nearer to the router and see what happens?

Or a photo of the PCB will be great too.

Ok, Move it to within 4 feet of my router. Same behaviour unfortunately.

Any video of the light blinking sequence?

Certainly: https://youtu.be/481qAkJUHPY

After a while (sometimes a minute, sometimes perhaps 20 minutes), it may come online.

Interesting. Can i check if the external antenna you added is suitable for 2.GHz operation?
Try removing the external antenna and see if it still happens.

Also, Can you use another WiFi network to connect and see if the behavior is the same?

Since it connects to the :cloud: successfully, it seems to indicate an environment issue vs software issue.

Thanks. Yes, it is listed for 2.4GHz and 5GHz.

I’ll try in another location and see what that looks like and feedback.


You can also try to turn off the 5Ghz channel the P1 should connect instantly.

Is this switching off the 5GHz channel on the router, or somehow on the P1? (I’m assuming you are talking about the router)

@mblackler, on the router as the neither the Photon or P1 support 5GHz.

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Thanks @peekay123.

I am having this same issue with an Electron - running on a different APN
It connects to the Service Provider, Ie gets the green led sequence completed. my debug gives me an IP address so I know it has connected to the network, it just can’t connect to Particle.

LED sequence is as described in the previous posts above.

  • blinks fast cyan
  • blinks really fast cyan
  • blinks red
  • maybe blinks green (its really fast)
  • cycle repeats.

I’m running v0.7.0-rc.6

I have one unit here that connects fine, and another 2 units that have this issue.

I have run particle doctor on one of the new units to reset the keys (as this fault has happened to me before and dodgy keys were the issue) This time it didn’t fix it.

These are straight out of the box

I found the issue - it had run out of credit on the SIM card

However it raises another issue.

I put some more credit on it, while the Electron device was running, and it did not connect

A reset of the electron didn’t fix it, only a removal of the power and reconnecting it.

I would have thought that when the money was put back on the SIM it should start working without the hardware needing to be powered off.

Any thoughts


A reset does only reset the µC but not the modem (for several reasons). If it had been “blacklisted” the modem needs to do a fresh start which can either be triggered by a power-cycle or via code.

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