Rainbow Electronics RF12B - 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).