Semtech LR1110 - Setpacketparam; Table 8-7: Coding Rate; Table 8-8: Lowdatarateoptimize; Table 8-9: Setpacketparam Command

LR1110
User Manual Rev.1.0
UM.LR1110.W.APP March 2020
56 of 130
Semtech
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• CR configures the Coding Rate
• LowDataRateOptimize reduces the number of bits per symbol:
8.3.2 SetPacketParam
The command SetPacketParam( ) configures the parameters of the RF packet for the selected modem. Since the parameters
are modem dependent, the description hereafter is valid only for the LoRa® modem.
• PbLengthTX defines the length of the LoRa® packet preamble.
 Coded on 2 Bytes, from 0x0001 (1) to 0xFFFF (65535). Minimum of 12 with SF5 and SF6, and of 8 for other SF
advised.
• HeaderType defines if the header is explicit or implicit:
 0x00= explicit header (default)
 0x01= implicit header
• PayloadLen defines the size of the payload (in Bytes) to transmit or the maximum size of the payload that the receiver
can accept.
Table 8-7: Coding Rate
CR Description Overhead Ratio
0x01 Short Interleaver CR= 4/5 1.25
0x02 Short Interleaver CR= 4/6 1.5
0x03 Short Interleaver CR= 4/7 1.75
0x04 Short Interleaver CR= 4/8 2
0x05 Long Interleaver CR= 4/5 1.25
0x06 Long Interleaver CR= 4/6 1.5
0x07 Long Interleaver CR= 4/8 2
Table 8-8: LowDataRateOptimize
LowDataRateOptimize Description
0x00 LowDataRateOptimize off
0x01 LowDataRateOptimize on
Table 8-9: SetPacketParam Command
Byte 0 1 2 3 4 5 6 7
Data from Host 0x02 0x10 PbLengthTX
(15:8)
PbLengthTX
(7:0)
HeaderType PayloadLen CRC InvertIQ
Data to Host Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)
0x00 0x00