Datasheet

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SX1272/73
WIRELESS, SENSING & TIMING DATASHEET
Rev. 2 - July 2014
©2014 Semtech Corporation
RegModemConfig
2
(0x1E)
7-4 SpreadingFactor rw 0x7
SF rate (expressed as a base-2 logarithm)
6
 64 chips / symbol
7
 128 chips / symbol
8
 256 chips / symbol
9
 512 chips / symbol
10
 1024 chips / symbol
11
 2048 chips / symbol
12
 4096 chips / symbol
other values reserved.
3 TxContinuousMode rw 0
0
 normal mode, a single packet is sent
1
 continuous mode, send multiple packets across the FIFO
(used for spectral analysis)
2 AgcAutoOn rw 0x01
0
 LNA gain set by register LnaGain
1
 LNA gain set by the internal AGC loop
1-0 SymbTimeout(9:8) rw 0x00 RX Time-Out MSB
RegSymbTimeoutL
sb
(0x1F)
7-0 SymbTimeout(7:0) rw 0x64
RX Time-Out LSB
RX operation time-out value expressed as number of symbols:
RegPreambleMsb
(0x20)
7-0 PreambleLength(15:8) rw 0x0
Preamble length MSB, = PreambleLength + 4.25 Symbols
See Section 4.1.1.6 for more details.
RegPreambleLsb
(0x21)
7-0 PreambleLength(7:0) rw 0x8 Preamble Length LSB
RegPayloadLength
(0x22)
7-0
PayloadLength(7:0)
rw 0x1
Payload length in bytes. The register needs to be set in implicit
header mode for the expected packet length. A 0 value is not
permitted
RegMaxPayloadLe
ngth
(0x23)
7-0
PayloadMaxLength(7:0)
rw 0xFF
Maximum payload length; if header payload length exceeds
value a header CRC error is generated. Allows filtering of packet
with a bad size.
RegHopPeriod
(0x24)
7-0
FreqHoppingPeriod(7:0)
rw 0x0
Symbol periods between frequency hops. (0 = disabled). 1st hop
always happen after the 1st header symbol
RegFifoRxByteAdd
r
(0x25)
7-0 FifoRxByteAddrPtr r n/a
Current value of RX databuffer pointer (address of last byte
written by Lora receiver)
(0x26) - (0x27) - Reserved r n/a Reserved
RegFeiMsb
(0x28)
7-4 Reserved r n/a Reserved
3-0 FreqError(19:16) r 0x0
Estimated frequency error from modem in 2’s compliment format.
MSB of RF Frequency error
(RegFeiMid
(0x29)
7-0 FreqError(15:8) r 0x0 Middle byte of RF Frequency Error
Name
(Address)
Bits
Variable Name
Mode Reset
LoRa
TM
Description
TimeOut SymbTimeout Ts⋅=
F
Error
FreqError 2
24
×
F
xtal
------------------------------------------
=