diff options
Diffstat (limited to 'watch-library/watch/watch_private.c')
| -rw-r--r-- | watch-library/watch/watch_private.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/watch-library/watch/watch_private.c b/watch-library/watch/watch_private.c index 88d80be9..8dfd10f9 100644 --- a/watch-library/watch/watch_private.c +++ b/watch-library/watch/watch_private.c @@ -32,6 +32,27 @@ void _watch_init() { SUPC->VREG.bit.SEL = 1; while(!SUPC->STATUS.bit.VREGRDY); + // set up the brownout detector (low battery warning) + NVIC_DisableIRQ(SYSTEM_IRQn); + NVIC_ClearPendingIRQ(SYSTEM_IRQn); + NVIC_EnableIRQ(SYSTEM_IRQn); + SUPC->BOD33.bit.ENABLE = 0; // BOD33 must be disabled to change its configuration + SUPC->BOD33.bit.VMON = 0; // Monitor VDD in active and standby mode + SUPC->BOD33.bit.ACTCFG = 1; // Enable sampling mode when active + SUPC->BOD33.bit.RUNSTDBY = 1; // Enable sampling mode in standby + SUPC->BOD33.bit.STDBYCFG = 1; // Run in standby + SUPC->BOD33.bit.RUNBKUP = 1; // Also run in backup mode + SUPC->BOD33.bit.PSEL = 0xB; // Check battery level every 4 seconds + SUPC->BOD33.bit.LEVEL = 31; // Detect brownout at 2.5V (1.445V + level * 34mV) + SUPC->BOD33.bit.BKUPLEVEL = 31; // Detect same level in backup mode + SUPC->BOD33.bit.ACTION = 0x2; // Generate an interrupt when BOD33 is triggered + SUPC->BOD33.bit.HYST = 0; // Disable hysteresis + while(!SUPC->STATUS.bit.B33SRDY); + + // Enable interrupt on BOD33 detect + SUPC->INTENSET.bit.BOD33DET = 1; + SUPC->BOD33.bit.ENABLE = 1; + // External wake depends on RTC; calendar is a required module. CALENDAR_0_init(); calendar_enable(&CALENDAR_0); |