A number of measurements were made today to determine the threshold for the maximum distance between the eMoodies. The XBee modules can detect the signals and give an indicator of how far away the other modules are through RSSI (received signal strength indicator). Two eMoodies were used, Cory and Steve .These values were observed today during the RSSI-testing:
Distance (in cm) | RSSI:
250 | 62
130 | 55-56
95 | 56-62
70 | 46
50 | 43-45
30 | 43-46
The RSSI values varied and were hard to distinguish from certain distances. After a discussion, the threshold was set to be 54 RSSI. If an eMoodie senses that the signal is > 54, it is classified as being “far away”, otherwise it is classified as being nearby.
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