nRF52832 2.048 MHz Clock

[Vala]

Hi,

I want to generate a 2.048MHz clock on one of the IOs of nRF52832. Could you comment on following questions?

1- Can I generate this frequency (with no load on CPU), using a 32MHz crystal or I have to use a more accurate crystal?

2- What is the most optimized way for doing so, from power consumption and clock accuracy point of view? A PWM or timer + compare + PPI?

-Vala

[Jørgen Holmefjord]

Yes, you could get 2 MHz, but not 2.048 MHz. If you are not using any of the radio features of the nRF52, you could use the internal oscillator, HFINT. The HFXO must be running to use the RADIO, NFC module or the calibration mechanism associated with the 32.768 kHz RC oscillator. If you use Bluetooth, a tolerance of ±40 ppm is required for HFXO (±60 ppm for proprietary 2.4 GHz). You can therefore not swap it for another crystal if you use the radio.

[Vala]

Thanks for your comment. This is the answer that I was looking for. I am using BLE. Therefore, the only option left is to use an external crystal for the sensor.