P0 Wireless N only mode NOT WORKING on 0.7.0 and later firmware

I’ve noticed some odd behavior with my P0 device. It seems that when I compile my code with 0.6.3 firmware I can connect to a wireless N only access point (ASUS RT AC66U that I have set in N mode only) but as soon as I bump compile and load 0.7.0 or 0.8.0rc4 firmware, I’m not able to connect to the network. It just times out and goes back to listening mode.

Using our previously shipping product I also notice this behavior where 0.6.3 and below firmware seems to connect properly, but 0.7.0 firmware and above does not.

Has anyone else run into this? Am I missing something relating to WPA enterprise or the other changes from 0.7.0 firmware?

The main reason we found this is that we are trying to get FCC certification pre-scanning done for our device and the latest firmware was not allowing us to communicate with an access point in N only mode.

Let me ping someone that might be able to help, @rickkas7 or @ParticleD are you able to assist?

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@peekay123 The spec sheet seems to say it supports b/g/n. Is that not true? https://docs.particle.io/datasheets/photon-(wifi)/photon-datasheet/

Also as mentioned in the post, I did try a set of firmware compiled with 0.6.3 and am able to connect to the router which I expressly set to N mode only for the 2.4 GHz mode but was unable to do so with 0.7.0.

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Hey there @sirhcil – thanks for the report. I’ve shared this internally so we can attempt to replicate.


Thanks @will. Let me know if you guys are able to replicate the issue or need more info.

@sirhcil, can you double check whether your AP has the 5GHz band deactivated or assigned with a different SSID?
One thing we know for sure to cause troubles is when the 2.4GHz and the 5GHz band share the same SSID. Some APs try to move traffic to the 5GHz band which is not supported on these devices (irrespective of WiFi flavour).


Hi @ScruffR - the AP may be broadcasting the 5GHz with the same SSID name but I will double check.

Even with that, as I mentioned earlier, the exact same device running 0.6.3 particle firmware will connect just fine to this wireless N mode-only router, but 0.7.0 particle firmware will not work. I compile the same user software using the CLI with the different particle versions and just load the different files to run the test.

@sirhcil, setting my router to Wireless N only, I was able to confirm that all my Photons did not reconnect to the router. When I reset the router back to b/g/n, the Photons connected again. However, please note that the SSID for the router’s 5GHz band is different from that of the 2.4GHz band.

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@sirhcil, thanks for the comment. In order to pinpoint the root cause, it’s required to remove any factor that might cause similar symptoms and hence interfere with the diagonisis.

Thanks for performing an independent test!

Hi all, I just tested it on a ASUS RT-N66U and with 2.4GHz 802.11n only, 0.6.0 connects, but 0.7.0-rc.1, 0.7.0 and 0.8.0-rc.8 do not connect. We will look into this to see what the issue is, and how it can be resolved.


Thanks @BDub. Let me know if you guys are able to track this down and when might be the earliest target release.

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We are tracking this issue here: https://github.com/particle-iot/firmware/issues/1556

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Any progress on a possible solution?

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Hi all! We have a PR that resolves this issue, slated for 1.1.0-rc.2 and 1.2.0-beta.2. If you have the ability to test PR #1755 to see if it resolves the issue for y’all, your feedback is appreciated.

Here’s a quick way to check out the PR and compile:

Ensure v1.0.1 doesn't connect to your WAP first (and that your issue is the 802.11n-only mode issue).  0.6.3 should connect to this router just fine.

git clone git@github.com:particle-iot/device-os.git (SSH)
// or
git clone https://github.com/particle-iot/device-os.git (HTTPS)

cd device-os/modules

git checkout fix/photon-80211n

modules $ make clean all -s PLATFORM=photon COMPILE_LTO=n APP=tinker program-dfu
// change above to P1 if necessary

Your Photon or P1 should now connect.

To make it easier, I just compiled some binaries for Photon and P1 for y’all to try. This is compatible with 1.1.0-rc.1 compiled apps, or you can just use the included tinker binary. You shouldn’t need the bootloader, but just in case it’s part of the natural build process so I zipped it all up.