[time-nuts] How to properly characterize 32kHz oscillators manually and with a microcontroller?

[Nick Sayer]

> On Jun 27, 2016, at 1:34 PM, Nick Sayer <nsayer at kfu.com> wrote:
> 
> 
> In the firmware, the timer that has the input capture ability is set to free-run at the system clock frequency. The ICP interrupt reports back the timer delta from the last interrupt. Nominally, you’d expect 16,384 counts. I calculate the delta and accumulate that for 10 seconds before reporting the result on the LCD.

Correction…

Nominally, you’d expect 10,000,000 / 16,384 counts.