Hi,
On page 195 of the cc2510 datasheet (swrs055f.pdf), it says:
The RSSI value read from the RSSI status register is a 2’s complement number. The following procedure can be used to convert the
RSSI reading to an absolute power level (RSSI_dBm).
1) Read the RSSI status register
2) Convert the reading from a hexadecimal number to a decimal number (RSSI_dec)
3) If RSSI_dec ≥ 128 then RSSI_dBm = (RSSI_dec − 256)/2 – RSSI_offset
4) Else if RSSI_dec < 128 then RSSI_dBm = (RSSI_dec)/2 – RSSI_offset
When I use the packet sniffer, the RSSI value from the received packet is negative already (anywhere from -30 to -100). I thought the RSSI should always be positive and without the unit, it is the RSS that is negative, but after the offset, the RSSI value is always positive.
Anyway, why the conversion from RSSI_dec to RSSI-dBm? And what does this conversion achieve?
Thanks!