diff options
| author | Noralf Trønnes <noralf@tronnes.org> | 2018-04-29 16:38:18 +0200 |
|---|---|---|
| committer | Noralf Trønnes <noralf@tronnes.org> | 2018-04-29 20:43:07 +0200 |
| commit | 62d7a800d76ffb020d0cb1076b54a8e049b08bee (patch) | |
| tree | 85bcb22e571c35cabfa30a1516bda773bdee4457 | |
| parent | 83e390714f696e58e34f4bcab5fb77ff1a5451fd (diff) | |
atmel-samd: RTC: Improve precision when setting datetime
The prescaler is not reset when setting the counter so we can be off by
as much as 1023/1024 seconds. Fix this by resetting the RTC module.
| -rw-r--r-- | ports/atmel-samd/common-hal/rtc/RTC.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/ports/atmel-samd/common-hal/rtc/RTC.c b/ports/atmel-samd/common-hal/rtc/RTC.c index d63e81305..680a88deb 100644 --- a/ports/atmel-samd/common-hal/rtc/RTC.c +++ b/ports/atmel-samd/common-hal/rtc/RTC.c @@ -64,6 +64,12 @@ void common_hal_rtc_get_time(timeutils_struct_time_t *tm) { } void common_hal_rtc_set_time(timeutils_struct_time_t *tm) { + // Reset prescaler to increase initial precision. Otherwise we can be up to 1 second off already. + uint32_t freqcorr = hri_rtcmode0_read_FREQCORR_reg(calendar.device.hw); + calendar_deinit(&calendar); + rtc_init(); + hri_rtcmode0_write_FREQCORR_reg(calendar.device.hw, freqcorr); + struct calendar_date date = { .year = tm->tm_year, .month = tm->tm_mon, |