Semtech LR1121 - Modems; Modem Configuration; Figure 8-1: Lora;(G)FSK; LR-FHSS Command Order

LR1121
User Manual Rev 1.1
UM.LR1121.W.APP Mar 2023
62 of 130
Semtech
Proprietary & Confidential
www.semtech.com
8. Modems
8.1 Modem Configuration
The LR1121 contains different modems capable of handling different constant envelope modulations. For the
LoRa®/(G)FSK modems and LR-FHSS modulation, the suitable command order is the following:
• The user must specify the modem to be used in command SetPacketType(...)
• SetModulationParams(...) configures the modem parameters (SF, BW, CR and LDRO)
• SetPacketParams(...) defines the RF packet parameters (Payload length, Implicit/explicit mode, …). This
command is not needed for LR-FHSS
• SetPaConfig(...) configures the PA settings used for RF packet transmission (which PA, supply mode…)
• SetTxParams(...) defines the PA parameters (output power, ramp time).
The suitable command order is the following:
Figure 8-1: LoRa /(G)FSK / LR-FHSS Command Order
SetModulationParams
SF,BW,CR,LDRO,bitrate,fdev
SetPacketType
GFSK/LoRa®/GMSK(LRͲFHSS)
SetPacketParams
PreambleLength,Implicit/Explicit,CRC,InvertIQ
SetPAConfig
PaSel,RegPaSupply,PaDutyCycle,PaHpSel
SetTxParams
Power,RampTime