Rssi distance estimation wrong


I’m looking to estimate the distance between my mobile and the beacon and I found using multiple beacon scanner (android) that the estimation distance is really wrong for ruuvitag against an iBeacon (I have a minew MS56).
While the iBeacon is estimated betwen 0,20m and 0,30m the ruuvi is estimated between 1,4m and 2,61m)…

Both the ruuvi and the ibeacon are positionned at the same distance and place from the mobile for the test.

I read that iBeacon contains a RSSI reference but it not seems to have an equivalent in eddystone. So I wonder how I can optimize the accuracy of the estimated distance.

See you


We have also noticed the problem. I think the problem is difficulty of calibration at 0m, and therefore I measured the signal strengths at 1 m and then subtracted 41 dB to compensate for the distance as instructed here.

You can find experimental Eddystone binary here. I think the results are now more reasonable, although they still vary a lot depending on orientation of tag and phone and if my body is in between or if there is a clear line of sight and so on.

We’ll run some tests on our end with a few different phones and setups, if you’re willing to help us out please test if the ranging is more accurate for you. Please note that the software is experimental and can have unreasonably high power consumption or other issues.

Hi otso,

I just install the test firmware and the estimated distance is far more accurate (not as much as the beacon I own but close enough) when distance is <1m but when the beacon is at more than 1m distance is all messy (not accurate at all in open air, worse than initially I think).
More over I don’t understand, why my 2 frames didn’t give the same distance (URL and UID frame) there is around 0,2m difference between the 2.

I’l try to do some more accurate testing and give you my feedback.

See you.