In order to test the interference effect of various objects, we set the motes up at a distance of .55 meters, with one horizontal, batteries down, usb pointing directly at the other mote. the second mote was vertical, with the board pointing at the first mote, usb pointing at the ceiling. we ran a control, a test with a person in the middle, a test with a person holding copious amounts of wire in the middle, and one with a modified roomba robot with attached camera assembly between the motes. (we had the roomba laying around the lab.) we found that the person and the wire had no significant effects, but the robot did.
there are three dots for each data point, a mean, one std dev up, and one std dev down.
Good experiment. So what it says, if I’m interpreting your data correctly, is that standing between two motes doesn’t seem to affect them very much. However, holding a large metal object, like a laptop (which is about the size of a Roomba), probably drops the signal down by 10-15%.
Comment by gthomas — August 26, 2009 @ 7:46 pm
yes. also the standard deviation of the readings goes way up when the roomba was introduced in between the two motes, meaning that any single rssi reading with a computer-like object in the middle will be less accurate.
Comment by E M — August 27, 2009 @ 2:28 pm
[...] various regions of the RSSI, such as providing greater separation between distances or orientations.Obstacle Interferance (inside puck) – one horizontal, one vertical, distance .55m. various obstacles: person, [...]
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