nRF51822: will RTC work without a 32 KHz input?

RE: nRF51822: will RTC work without a 32 KHz input?

Gerry Ortoli — Tue, 11 Feb 2014 10:02:14 GMT

Thanks for the info. I'll pass this to the hardware team & maybe the next rev of the board will be different!

RE: nRF51822: will RTC work without a 32 KHz input?

Ole Morten — Mon, 10 Feb 2014 12:13:08 GMT

Take a look at this: https://devzone.nordicsemi.com/index.php/what-low-frequency-clock-sources-can-i-use

RE: nRF51822: will RTC work without a 32 KHz input?

Gerry Ortoli — Sun, 09 Feb 2014 15:38:47 GMT

OK, knowing that I'm using the Soft Device, how do I specify use of the internal 32 KHz oscillator? The reference manual describes this option but I can't seem to find how to do it. The only thing close is the BLE_STACK_HANDLER_INIT() function, but the description implies this just affects the stack, not the chip configuration. Help?

RE: nRF51822: will RTC work without a 32 KHz input?

ovrebekk — Sun, 09 Feb 2014 15:25:15 GMT

You will need a 32 kHz input, but you can use the internal 32 kHz RC oscillator instead of the external crystal.

Just be aware that the internal RC oscillator is several orders of magnitude less accurate than the external crystal.