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adafruit/circuitpython#1046 handle overflows in the RTC counter

This commit is contained in:
Nick Moore 2019-02-12 13:11:08 +11:00
parent f846fa109e
commit 6206fa9a82
1 changed files with 14 additions and 3 deletions
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17
ports/nrf/common-hal/rtc/RTC.c
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@ -35,9 +35,14 @@
#include "nrfx_rtc.h"
#include "nrf_clock.h"
// We clock the RTC very slowly (8Hz) so that it won't overflow often.
// But the counter is only 24 bits, so overflow is about every 24 days ...
// For testing, set this to 32768 and it'll overflow every few minutes
#define RTC_CLOCK_HZ (8)
static uint32_t rtc_offset = 0;
volatile static uint32_t rtc_offset = 0;
int8_t rtc_calibration = 0;
const nrfx_rtc_t rtc_instance = NRFX_RTC_INSTANCE(0);
@ -49,7 +54,9 @@ const nrfx_rtc_config_t rtc_config = {
};
void rtc_handler(nrfx_rtc_int_type_t int_type) {
// do nothing
if (int_type == NRFX_RTC_INT_OVERFLOW) {
rtc_offset += (1L<<24) / RTC_CLOCK_HZ;
}
}
void rtc_init(void) {
@ -59,6 +66,7 @@ void rtc_init(void) {
nrfx_rtc_counter_clear(&rtc_instance);
nrfx_rtc_init(&rtc_instance, &rtc_config, rtc_handler);
nrfx_rtc_enable(&rtc_instance);
nrfx_rtc_overflow_enable(&rtc_instance, 1);
}
void common_hal_rtc_get_time(timeutils_struct_time_t *tm) {
@ -75,8 +83,11 @@ void common_hal_rtc_set_time(timeutils_struct_time_t *tm) {
// A positive value speeds up the clock by removing clock cycles.
int common_hal_rtc_get_calibration(void) {
return 0;
return rtc_calibration;
}
void common_hal_rtc_set_calibration(int calibration) {
if (calibration > 127 || calibration < -127)
mp_raise_ValueError(translate("calibration value out of range +/-127"));
rtc_calibration = calibration;
}