Cannot get more than 3 Bluz's to connect through gateway


I am trying to connect 8 Bluz’s through a gateway but I can’t get more than 3 to work. Are there any known issues that updated firmware would correct?


There is currently a limit of 3 in the latest firmware. This has to do with the fact that the Photon currently doesn’t support more then 5 socket connections, so it can only handle 3 bluz DK (1 socket used by the Photon for cloud connectivity, 1 socket used by the nrf51 gateway for cloud connectivity, leaving 3 for bluz DK)

We have some feedback from Particle on a possible work-around, if it works then we may have to issue special firmware for the Photon for the time being. I will try and get this tested and confirmed as soon as possible.


If I have two gateways close to each other. Will 6 Bluz’s be able to connect? Or will there be problems with the Bluz’s trying to figure out which gateway to connect with?


Yes, that will work. The gateways initiate the connection to a bluz DK, so you can use multiple and thee DK’s will just randomly attach to one gateway or the other.


Cool. Thanks. If you need someone to help test out the workaround from Particle I am all set to try it out!


Is the limit still at 3 Bluzs connecting through a gateway? The Order pages states that 8 can connect to the Cloud through a gateway.


Yes, the limit is still 3.

Do you have an immediate need for more? This hasn’t been a really big issue for anyone yet, so we haven’t pushed to get it increased. Please let me know if that is different for you.


@eric Add me to the list of wanting more!


Yes, it would be very nice to spread across more DK boards the cellular fees, the labor/hassle of connecting a gateway to a WiFi network, and the need to find AC power for the gateway. I’d like to see 5 connections but 8 would be better.

It would be less confusing if you would remove the “Connect up to 8 Bluz DK boards to the cloud” on your Order page.



I would also like to have more than 3 dk connected to one gateway, any plans on fixing that?


Yes, it is planned. We are waiting on changes from the Particle side, notably:



Hi there. I am facing the same issue - unable to connect more than 3 DKs to a shield at a time. I am using local communication between the DK and the shield and using an Electron to connect the shield to the cloud. Has the limit increased to 8 yet? I have an immediate need for it. :frowning:

Thank you.


We have a solution that we never rolled out as a GA feature. The limit is 6 now, that is as far as we have tested. If you want to email us, I can send you the firmware and instructions to load it.


Hi Eric, do you think it would be cool for those future brave souls that need this improvement if that info was available in a topic in this forum (with a big disclaimer about risks on top)?


Gustavo, I’m glad you bring it up. Even though I don’t have more than 3 DKs, I tagged this thread so I would start bugging Eric for the instructions later on. I plan on having a fourth DK online around January.

Eric, since the docs say the gateway supports 8 DKs, can we have something on GitHub that explains the risks and let us work around the limitations?

Edit: I typed BK instead of DK:blush:


Yes, I will publish this. The risks at this point are mostly mitigated for 6 devices. That works just fine, and I will roll this out.

Going to 8 would potentially be risky from a RAM usage perspective. Each connection requires its own buffer and there is limited RAM on the nRF51. That isn’t aupported yet, but could be possible.


Emailed. Thanks, Eric.