I purchased the UBLOX XPLR-AOA-1 eval kit and have it working successfully. The kit came with one C209 tag and one c211 antenna board. I’d like to purchase a extra tag. I’ve been advised that the C209 tag is not sold separately but I should be able to use any Eddystone BLE with 5.1 direction finding capability. I know it uses a NINA-B406 UBLOX chip and I see they are available on DigiKey but would prefer to buy a complete tag. Can I use another brand of tag or possibly an ESP32?

I am going to send this to the Product Specialist. I am not sure on this question.


Using a different tag than the C209 is not recommended. You could try it but the tag would need to flashed with the appropriate firmware in order to be seen by the C211.


My distributor DIGIKEY (where I asked this question) does not sell C209 tags individually (not listed) so… I’m left with buying another full XPLR kit just to get another tag? That’s not going to happen unless I need another antenna board. Let me rephrase this: WHERE CAN I BUY A SPARE C209 TAG (or something that will work the same)?

I apologize but the C209 tags are not sold separately at this time. This product is manufactured for proof of concept purposes. There are two options for purchasing the C209 tags and the C211 board at this time, they are the one you purchased, XPLR-AOA-1, and XPLR-AOA-2.
There will be additional options coming in the future.

I, too, would like to buy a few more C209 tags.

Unfortunately, these are still not sold separately. My understanding is they will be in the future. Please keep checking back.
Thank you.

I assume that u-blox may not want to sell the C209 tags separately because they are only meant for demonstration and they don’t want people to buy them to use for any other purpose. It’s likely that since they are only meant for demonstration that they are not certified as an end-use product from the FCC, etc.

Doing a little digging, I found a forum post on the u-blox website here where someone had asked about emulating the C209 tag, and they gave some useful information about attempting this using either the nRF52811 or the nRF52833-based platforms following the information given in section 4.4 of the ANT-B10 Direction Finding Antenna Board document.

Here are links to some evaluation and development boards utilizing either of those two chips. No guarantee that any one of these might be more or less suitable to the task, but at least something to consider: