Semtech LoRa Edge LR1110, User Manual

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LR1110
User Manual
Rev.1.0
UM.LR1110.W.APP March 2020
57 of 130
Semtech
www.semtech.com
In explicit header mode:

PayloadLen =0: reception of any payload length between 0 and 255 Bytes allowed.

PayloadLen = N: reception of any payload length between 1and N Bytes accepted. Payload lengths of 0 or > N are
rejected and result in a HeaderErr IRQ.
In implicit header mode, PayloadLen configures the exact length of the payload to be transmitted or received.
• CRC defines if the CRC is OFF or ON:

0x00= CRC OFF

0x01= CRC ON
• InvertIQ defines if the I and Q signals are inverted.

0x00= non inverted IQ

0x01= inverted IQ
This command will fail if no packet type has been set.
8.3.3 SetCad
The command SetCad( ) activates the CAD feature.
8.3.4 SetCadParams
The command SetCadParams( ) defines the LoRa® CAD parameters.
•
SymbolNum defines the number of symbols used for the CAD detection
•
DetPeak and DetMin define the sensitivity of the LoRa® modem when trying to correlate to actual LoRa® preamble
symbols. These two settings depend on the LoRa® spreading factor and Bandwidth, but also depend on the number of
symbol used to validate or not the detection. Choosing the right value must be carefully tested to ensure a good
detection at sensitivity level, and also to limit the number of false detections.
Application note AN1200.48 provides guidance for the selection of the CAD parameters.
Table 8-10: SetCad Command
Byte 0 1
Data from Host 0x02 0x18
Data to Host Stat1 Stat2
Table 8-11: SetCadParams Command
Byte 0 1 2 3 4 5 6 7 8
Data from
Host
0x02 0x0D Symbol
Num
DetPeak DetMin CadExit
Mode
Timeout
(23:16)
Timeout
(15:8)
Timeout
(7:0)
Data to
Host
Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
IrqStatus
(15:8)
IrqStatus
(7:0)
0x00 0x00 0x00