Rf12b – Rainbow Electronics RF12B User Manual
Page 16
RF12B
Bits 7-5 (i2 to i0): Receiver baseband bandwidth (BW) select:
i2
i1
i0
BW [kHz]
0
0
0
reserved
0
0
1
400
0
1
0
340
0
1
1
270
1
0
0
200
1
0
1
134
1
1
0
67
1
1
1
reserved
Bits 4-3 (g1 to g0): LNA gain select:
g1
g0
Bits 2-0 (r2 to r0): RSSI detector threshold:
[dBm]
r2 r1 r0 RSSI
setth
0
0
0
-103
0
0
1
-97
0
1
0
-91
0
1
1
-85
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relative to maximum [dB]
1
0
0
-79
0
0
0
0
1
-6
1
0
1
-73
Reserved
1
1
0
1
0
-14
Reserved
1
0
1
1
1
-20
The RSSI threshold depends on the LNA gain, the real RSSI threshold can be calculated:
RSSI
th
= RSSI
setth
+ G
LNA
7.Data Filter Command
bit 15 14 13 12 11 10 9
8
7 6 5
4
3
2 1 0 POR
1 1 0 0 0 0 1
0
al
ml
1
s
1
f2
f1
f0
C22Ch
Bit 7 (al): Clock recovery (CR) auto lock control, if set.
CR will start in fast mode, then after locking it will automatically switch to slow mode.
Bit 6 (ml): Clock recovery lock control
1: fast mode, fast attack and fast release (6 to 8 bit preamble (1010...) is recommended)
0: slow mode, slow attack and slow release (12 to 16 bit preamble is recommended)
Using the slow mode requires more accurate bit timing (see Data Rate Command).