How do I calculate frequncy for wireless module RF96

Thread Starter


Joined May 24, 2012
I was reading datasheet for module RF96 (datasheet attached), I understand that we have to set register values to set carrier frequency as descrubed on the page 103, this is also described at some other parts of the datasheet like Pages, 13, 53, 77, 88

Formula described to calculate configuration value for registers RefFrLsb, RefFrMid, RefFrMsb is as below (ref page 103)
fRF = (XOSC) * Fr f / 2^19

Where they did not described what are these variables RF and Fr, through different tables in the datasheet i took the idea and tried to calculate the value as they described in the example:
OSC = 32MHz
Frequncy = 434 MHz

fRF = 32,000,000 * 434,000,000 / 524288

fRF = 13,888,000,000,000,000 / 524288

fRF = 26,489,257,812.5

which is 0x6 2AE1 FF54 and it does not match the datasheet calculated value 0x6C 8000

I'm looking for help where am I making mistake. Thanks