Looking for some help with some CC11xx registers settings with respect to compliance with the IEEE 802.15.4 specification.
We are looking to use a phy of 433.92 MHz, 250 kbps, and MSK modulation.
Our first instinct was to run the radio in MSK mode, but our end customer wants continuous phase FSK, this was suggested by TI as a cleaner way
better approach since this would produce a cleaner MSK signal. Of course this all seems to be a bit odd to me as the chip already has a native MSK mode. So I am trying to understand a little better what is going on. Furthermore, I have tried setting a CC1150 up to transmit in the CPFSK mode. I assumed that our MSK receiver (CC1100) should be able to receive the CPFSK signal from the CC1150 as it is a “Cleaner MSK Signal”. Unfortunately, it does not. So here is what I need to get clarification on:
- I assume that I have the settings correct for the radio to be in CPFSK mode -> 433.92MHz, 2-FSK, 250 Kbps, 62.5KHz deviation. Is this correct, or did I miss a setting? Perhaps the settings in the MSK receiver are not correct.
- There is a setting in the deviation register for the MSK mode that I don’t understand. Can you please explain WRT the MSK signal what this means? See below
When MSK modulation is enabled:
Specifies the fraction of symbol period (1/8-8/8) during which a phase change occurs (‘0’: +90deg, ‘1’:-90deg). Refer to the SmartRF Studio [11] software for correct DEVIATN setting when using MSK.
3. Is CPFSK the same as MSK? They are very similar, but I have done some reading that suggests that these modulations do have some subtle differences. So I am wondering if this is why I can’t get my receiver to work.
Thanks
Jamie
