Current Blue 2-1 Matter/Thread upgrade

I recently purchased a handful of the Blue 2-1 refurbs because they state they’re “upgradable to Matter/Thread”, however, now I’m wondering if that’s still the case. I saw on the Jonagold thread that the current Blue 2-1’s are still using the MG21 chip. I made the poor assumption that the refurbs were getting upgraded to the latest chipsets. I need to purchase half a dozen more switches, but wanted to ask a few questions about the upgrade first.

  1. I understand that the MG21 may require a hard connection to do the Matter/Thread upgrade, is this a 1 time requirement? Or will it need a hard connection for future updates also? I’m a software engineer with plenty of hardware experience (who is looking for new opportunities if you’re hiring :smile:) so doing it once doesn’t bother me…but needing to do it many times just seems inconvenient.

  2. My plan was to get the current Blue 2-1’s and then upgrade them to Thread/Matter when that stack gets all the features I need working. Are there any foreseeable reasons that the MG21 Blue’s won’t won’t get the same features as the MG24 Blue’s?

  3. If I preorder the Blue’s on the website now, that will be for MG24 chipsets, correct?

Hey great questions, I’m happy to jump in and answer them!

Yeah, it’s been quite the ride trying to figure out what can/cannot be done with the MG21/MG24’s, etc. We were told initially that the MG21’s would be upgradeable via OTA to Matter. This was back in 2021 when we first kicked off the project.

Then around July 2021, the project manager for the manufacturer backtracked and said that it would not allow OTA, but rather a serial connection (hence the reason why we put the serial port on the PCB):

So as far as I’m aware, this is still the case for the MG21. However, this statement about the MG24 is now also being backtracked and they’re saying the MG24 even needs a serial port because the Matter stack has grown (which also leads me with concern over the MG21 – it may just be a very basic upgrade and there won’t be enough room for all the advanced features).

Silicon Labs won’t provide a clear answer either, they just keep pushing us to buy the latest chipset (now they’re talking about the MG26!)

As soon as we wrap up the Thread/Matter firmware, I wanted the engineer to look into figuring out how to upgrade the MG21’s, but that probably won’t be until later in March.

Even so, as mentioned, I don’t think we’ll be able to flash the full feature-set on the MG21’s as there’s just not enough room.

Now that you have the backstory, let’s answer your questions:

This would just be a one-time thing. Once it’s transitioned over to Matter, it can OTA Matter to Matter. My understanding also is that once you switch over to Matter, you can’t go back to Zigbee. But I could be mistaken, there’s a lot of random threads I am in and it gets confusing lol.

My advice is that if you want all the bells and whistles to just invest in the Thread/Matter switches now as I am 99% sure the MG21’s will not get the full feature-set due to space constraints.

But I’ve also been telling people that anyone who’s purchased the Blue 2-1’s now already likely has a smart hub that supports Zigbee and I really don’t see the need to switch over to Matter as those hubs will continue to support Zigbee even after the Matter implementation is complete. The whole premise of Matter is to work with all hubs (I know there’s other benefits, but this is the main one) and most hubs out there now already have integrations with each other, so I just don’t see the point of switching over.

In other words, if you have a Blue Series switch now with all the bells and whistles, it will continue to have the bells and whistles forever as I don’t see Zigbee going away ever. There’s too many large companies that support it (Amazon, Philips, SmartThings, etc) that have existing products out there that it would be a bad business decision to come out with a new hub that doesn’t support their prior products.

The Blues that have the MG24’s are the Fan switch and the Fan/Light Canopy. The 2-1’s still have the MG21’s in them until the foreseeable future. We made a deal with our manufacturer that we would purchase their supply of MG21’s before upgrading in exchange for reduced R&D costs (they purchased too many MG21’s and were stuck with them). My best guess is we’ll go through them this summer, but it’s hard to estimate. By then, I’m sure the MG26’s will be the new talk of the town lol.


Appreciate the update, Eric.

Horrible news about the MG24 2-in-1’s though. Your manufacturer really screwed you (unless those R&D discounts were significant), as I’m sure you have countless potential customers holding out on their purchases so they’re not buying outdated hardware. (ESPECIALLY now that it’s apparent the LEDs don’t match between the MG24 fan switches and the MG21 2-in-1’s.)

Sigh… guess we’ll be waiting even longer to get our regular lights upgraded to Inovelli zigbee switches.

Thanks again for the update and transparency though.


Can you please point me where it’s been mentioned? I’ve missed it and I was about to order the MG21, not wanting to wait until summer. Thanks!

I preordered 10x blue mmWave presence sensor, I want my 2-1 LED to match the mmWave which will be MG24.

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Check out Eric’s message here:

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It wasn’t a 21 vs 24 thing, the mfg simply changed leds in the different product. I believe they are using the same leds going fwd and there are also 2 different mfgs for devices now so they’re also being careful of led choice between mfg going fwd.