djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

atmel-samd: RTC: Improve precision when setting datetime

Browse Source 
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.
This commit is contained in:
Noralf Trønnes 2018-04-29 16:38:18 +02:00 committed by Dan Halbert
parent 6855541e33
commit 681399f8db
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
ports/atmel-samd/common-hal/rtc/RTC.c
View File

@ -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,