Tuesday, 25 July 2017

More RSSI adventures

Some updates on the wireless system.

Having run a number of more trials of RSSI for distance in different conditions it is now obvious that RSSI is unlikely to be helpful over long ranges. I have included two graphs of my results, the first is of the raw data, which includes all measurements made (I took multiple for the same distance for almost all tests). The graph shows the general mess of values I was getting with very little correlation between distance and RSSI, especially when comparing results between tests.

This is evident in the second graph, which colour codes the results for the trail they were taken in. The most likely reason for these bizarre plots is reflections of the transmitted signal off of surrounding objects. This would explain why  the shape of the plots can vary so wildly between setting that the experiment was taken in, but remain fairly consistent for the same setting.  


The raw data, an enormous mess!

Results sorted by trial (with data averaged to ensure that there is only one point for each distance per trial). Clearly the devices surrounding affect the RSSI readings to a huge extent.
This is no problem for the project, it simply means that the RSSI readings are only effective over a short range. This can be easily counteracted by simply adding more receivers!

I just have to work out how to not clog up the airwaves...

Until next time!

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