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)

[Luis]

Depends on what you exactly want to achieve. I worked on this matter a few years ago and it is quite difficult. Using bluetooth we got nice results in open spaces without obstacles, using very omnidirectional antenas, a very high broadcast frequency, knowing the relative orientation of each tracked object by a different method (IMU transmitted by BLE), and lots of filtering... and of course each unit was calibrated. As endnode said, very difficult to extend to commercial generic products. There are other solutions, take a look at the loco positioning system: store.bitcraze.io/.../indoor-explorer-bundle. Again, if you try them indoors and with obstacles around, things start to get crazy.