Hi all,
I'm a student and i'm working with ZigBee-Freescale chip MC13224.....I have two two questions....I'd like to know the distance between two nodes by the RSSI value.I'd like to obtain a RSSI value from a received packet, How can i do that?.......I think that i can obtain the RSSI value from the LQI value, so....What is the relationship between these two quantities?....Where is defined?...
Thanks all
Hi
from brief look into MC1322xRM.pdf you can see:
The MC1322x IEEE 802.15.4 fully-compliant transceiver provides a complete 2.4 GHz radio with 250
Kbps Offset-Quadrature Phase Shift Keying (O-QPSK) data in 5.0 MHz channels and full
spread-spectrum encode and decode. The modem supports transmit, receive, clear channel assessment
(CCA), Energy Detect (ED), and Link Quality Indication (LQI) as required by the 802.15.4 Standard.
The receiver block supports ED level detection function for reporting CCA level and LQI for a
received packet. The LQI level is calculated from several reported hardware levels and is reported as an
8-bit hex value from 0x00 to 0xFF compliant with the IEEE 802.15.4 Standard. Freescale’s 802.15.4 MAC
and 22xSMAC report LQI through function calls:
• The value 0x00 equates to about -100dBm
• The value 0xFF equates to about -15dBm
A simple conversion formula is:
Input Power (dBm) = (LQI / 3) - 100
function calls used in the MC13224 MAC codebases.
Codebase Function Call (Primitive)
MLME-SCAN.request
best regards
Pavel
I would like to know this too