BLE4.0 TX frequency

[wiki]

Hello NORDIC

We found that TX frequency error is quite large. Is it able to compensate TX frequency by software ?

[RK]

How large? How have you measured it? Is this a reference design or your own custom board? If custom then how tuned is your crystal oscillator as that is the largest factor in TX frequency.

No you can't fix it in software.

[John]

Well, there appears to be trim registers for the radio peripheral that could be used to adjust the TX frequency. Not a game I'd want to be playing though.

[RK]

I see they exist, however as the radio is marked as a blocked device when using the softdevice (and I did make the assumption here that a softdevice is in use) they're not usable, and I didn't find an API point which exposed them, I discounted being able to use those.

[wiki]

really？can you descript it in detail ? Which register can be set in nrf51822 ?

Thanks !

[RK]

Are you running a softdevice? Those registers are part of the RADIO module so you can't access them. So they're no use to you and you have to fix the crystal oscillator. Have you read the Crystal Oscillator White Paper which explain this?