Hello everyone: I am implementing a power control algorithm in mica2 node, I modify s-mac to add the power control part. I use the formula Pt-min=Sensitivity*Pt/Pr to compute the minimum’s transmitting power. where Pr is RSSI, Pt is sender node current transmitting power, Sensitivity is -105dbm According to http://www.xbow.com/Support/Support_pdf_files/MPR-MIB_Series_Users_Manual.pdf RSSI(dBm)=-51.3*Vrssi-49.2 for 433 and 315 MHz Motes Vrssi=Vbatt*ADC_Counts/1024 ( here ADC_Counts is the raw_rssi, is it correct?) Vbatt=Vref*ADC_FS/ADC_Count Where: Vbatt=Battery voltage ADC_FS=1024 Vref=External voltage reference=1.223V So Rssi (dBm) =-51.3*(Vbatt*raw_rssi/1024)-49.2 My program is as follows: // convert rssi to dbm rssi=(-51*voltage*raw_rssi/1024 )-49; // convert rssi to dbm here, voltage I use mv,not v , is it correct? I do experiments, the result show raw rssi is [15,29] [31,48] [65,85], when distance is 1meter,7meter,and 14meter. But when it converted to dbm using the above formula, the result is [-1783 ,-887 ] ,[ -2956,-1936 ], [-1987 , -712], I know the result is wrong. But, I can’t find where the problem is?
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