Bluetooth beacons positioning accuracy?

[MikeLemon]

I'm planning to use one of those beacon platforms:

www.ebay.com/.../352167746226

www.ebay.com/.../112493464451

for a close proximity positioning system now I'd like to know what would be the accuracy of such a system?

What could be done to improve it?(even if it means upgrading to nrf52832 or nrf52840)

[endnode]

Have you searched for the same Q&As on this forum? There are many and the conclusions from many people are roughly the same... accuracy without any special care will hardly be better then "is the object in this room or the next". There are of course methods how to make the system better, many academic papers, many commercial companies claiming sub 2m accuracy in almost real time BUT you need to understand that they have teams of 5-50 people working on it for 2-5 years, full time. Good luck.

[endnode]

Note that you can maybe get something in decimeter rage in laboratory as science paper but that won't use off-the-shelf BLE modules or beacons but rather combine several technologies (e.g. BLE + WiFi in 2.4GHz + UHF + sub-GHz or ultra-wide-band...) and have pretty expensive custom hubs (in hundreds or thousand USD range) in very close distance (like few meters from each other to build very dense grid). Impossible to commercialize in such form...