diff options
Diffstat (limited to 'watch-library/hardware/watch/watch_private.c')
| -rw-r--r-- | watch-library/hardware/watch/watch_private.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/watch-library/hardware/watch/watch_private.c b/watch-library/hardware/watch/watch_private.c index e4fa4b9a..241ff40a 100644 --- a/watch-library/hardware/watch/watch_private.c +++ b/watch-library/hardware/watch/watch_private.c @@ -37,6 +37,18 @@ void _watch_init(void) { SUPC->VREG.bit.SEL = 1; while(!SUPC->STATUS.bit.VREGRDY); + // check the battery voltage... + watch_enable_adc(); + uint16_t battery_voltage = watch_get_vcc_voltage(); + watch_disable_adc(); + // ...because we can enable the more efficient low power regulator if the system voltage is > 2.5V + // still, enable LPEFF only if the battery voltage is comfortably above this threshold. + if (battery_voltage >= 2700) { + SUPC->VREG.bit.LPEFF = 1; + } else { + SUPC->VREG.bit.LPEFF = 0; + } + // set up the brownout detector (low battery warning) NVIC_DisableIRQ(SYSTEM_IRQn); NVIC_ClearPendingIRQ(SYSTEM_IRQn); @@ -47,8 +59,8 @@ void _watch_init(void) { SUPC->BOD33.bit.RUNSTDBY = 1; // Enable sampling mode in standby SUPC->BOD33.bit.STDBYCFG = 1; // Run in standby SUPC->BOD33.bit.RUNBKUP = 0; // Don't 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.PSEL = 0x9; // Check battery level every second (we'll change this before entering sleep) + SUPC->BOD33.bit.LEVEL = 34; // Detect brownout at 2.6V (1.445V + level * 34mV) SUPC->BOD33.bit.ACTION = 0x2; // Generate an interrupt when BOD33 is triggered SUPC->BOD33.bit.HYST = 0; // Disable hysteresis while(!SUPC->STATUS.bit.B33SRDY); |