OL2385SWUG datasheet(41/64 Pages) NXP

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NXP Semiconductors

OL2385SWUG

SIGFOX software driver

OL2385SWUG

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User guide

Rev. 2.1 — 6 April 2018

41 / 64

Figure 29. Update PA curve values

Figure 30. Read updated PA curve values

7.2.2 Legacy commands

The following is a set of essential commands are

no longer required for OL2385

firmware versions after version number 01.11.01.20.03.20.17:

7.2.2.1 Temperature based frequency calibration

The next command for any device can be Temperature frequency calibration. This

command also needs to be done only once after flashing new firmware on the OL2385.

Temperature frequency calibration is optional. If you choose to skip this command, some

TX and RX scenarios might not work. The crystal used on the boards has, sometimes,

an initial offset in the generated frequency depending on its temperature. Therefore,

the actual frequencies generated from the board differ slightly from the commanded

frequency. For example, if a command to start an unmodulated continuous wave

at 868.13 MHz is given, one can see on a spectrum analyzer that the peak of the

spectrum is not exactly at 868.13 MHz, but is at an offset. This frequency offset can be

compensated on the device by getting the temperature behavior curve from the crystal

manufacturer. Such a curve over temperature with ppm values can be then sent to the

OL2385 using the SPI command Temperature_frequency_calibration. These ppm values

can be translated to absolute Hz value on OL2385. An example of such a curve for an

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