Semtech LoRa Edge LR1110, User Manual

Page: 20 / 130

LR1110
User Manual
Rev.1.0
UM.LR1110.W.APP March 2020
20 of 130
Semtech
www.semtech.com
2.4.1 CalibImage
The CalibImage( ) command launches an image calibration for the given range of frequencies Freq1 and Freq2 .
By default, the image calibration is made in the band 902 - 928 MHz. Nevertheless, it is possible to request the device to
perform a new image calibration at other frequencies. The frequencies are given in 4MHz step (Ex: 900MHz -> 0xE1).
Once performed, the calibration is valid for all frequencies between the two extremes used as parameters. Typically, the
user can select the parameters freq1 and freq2 to cover any specific ISM band. If twice the same frequency is given as
argument, only one calibration at the given frequency is performed.
In case of POR or when the device is recovering from power down or sleep mode without retention, the image calibration
is performed as part of the initial calibration process and for optimal image rejection in the band 902 - 928 MHz. However
at this stage the internal state machine has no information whether an XTAL or a TCXO is fitted.
The command will operate in any mode of the device. At the end of the calibration procedure, the device returns to Standby
RC.
Note: Contact your Semtech representative for the other optimal calibration settings outside of the given frequency bands.
2.4.2 Calibrate
The Calibrate( ) command calibrates the requested blocks defined by the CalibParams parameter.
Table 2-6: CalibImage Command
Byte 0 1 2 3
Data from Host 0x01 0x11 Freq1 Freq2
Data to Host Stat1 Stat2
IrqStatus
(31:24)
IrqStatus
(23:16)
Table 2-7: ISM Band
Frequency Band [MHz] Freq1 Freq2
430-440 0x6B 0x6E
470-510 0x75 0x81
779-787 0xC1 0xC5
863-870 0xD7 0xDB
902-928 0xE1 (default) OxE9 (default)
Table 2-8: Calibrate Command
Byte 0 1 2
Data from Host 0x01 0x0F CalibParams
Data to Host Stat1 Stat2 IrqStatus(31:24)