Using RC oscillator for BLE init without calibration, beacon mode.

[Brian]

Hey all,

Quick question. If we want to send BLE advertisements, beacons, for just 1-2 seconds, then shutdown into SYSTEM_OFF mode, could we initialize the BLE soft device with the RC oscillator without it being calibrated by the HF crystal? We don’t need a precise clock. No BLE connection, just beacon.

For instance, beaconing for 2 seconds, and using an 8 second calibration period?

SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_8000MS_CALIBRATION, NULL);

Would this be the lower power method compared to using the 32KHz crystal, as long as we shutdown quickly (before 8 seconds). OR is the RC oscillator calibrated at the start of that 8-second period?

Also -- what's clocking the uP itself, at start-up? It's the RC oscillator, right? Is it ever calibrated if no BLE is ever used?

Thanks! Brian

[Hung Bui]

Hi please create a new ticket. This is 8 years old