Enable RTC and deep sleep (stop mode)

This commit is contained in:
Thomas Kolb 2016-08-14 01:38:19 +02:00
parent 6fc7e27c0b
commit d313860804

View file

@ -3,6 +3,9 @@
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/dma.h>
#include <libopencm3/stm32/timer.h>
#include <libopencm3/stm32/rtc.h>
#include <libopencm3/stm32/pwr.h>
#include <libopencm3/stm32/exti.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/cm3/systick.h>
@ -33,6 +36,19 @@ volatile int wait_frame = 1;
#define ADC_NUM_CHANNELS 3
volatile uint16_t adc_values[ADC_NUM_CHANNELS];
static void unlock_rtc_access(void)
{
pwr_disable_backup_domain_write_protect();
RTC_WPR = 0xCA;
RTC_WPR = 0x53;
}
static void lock_rtc_access(void)
{
RTC_WPR = 0xFF;
pwr_enable_backup_domain_write_protect();
}
static void init_gpio(void)
{
// Set up UART TX on PB6 for debugging
@ -79,6 +95,39 @@ static void init_clock(void)
rcc_periph_clock_enable(RCC_DMA);
}
static void init_rtc(void)
{
// RTC clock setup
// see libopencm3-examples::examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c
/* turn on power block to enable unlocking */
rcc_periph_clock_enable(RCC_PWR);
pwr_disable_backup_domain_write_protect();
/* reset rtc */
RCC_BDCR |= RCC_BDCR_BDRST;
RCC_BDCR &= ~RCC_BDCR_BDRST;
// use LSI for RTC
rcc_osc_on(RCC_LSI);
rcc_wait_for_osc_ready(RCC_LSI);
/* Select the LSI as rtc clock */
RCC_BDCR |= RCC_BDCR_RTCSEL_LSI;
/* ?! Stdperiph examples don't turn this on until _afterwards_ which
* simply doesn't work. It must be on at least to be able to
* configure it */
RCC_BDCR |= RCC_BDCR_RTCEN;
pwr_enable_backup_domain_write_protect();
nvic_enable_irq(NVIC_RTC_IRQ);
exti_set_trigger(EXTI17, EXTI_TRIGGER_RISING);
exti_enable_request(EXTI17);
}
static void init_timer(void)
{
// *** TIM1 ***
@ -183,6 +232,83 @@ static void init_adc(void)
}
static void deepsleep(uint32_t duration_secs)
{
uint32_t tmp = 0;
// unlock RTC registers
unlock_rtc_access();
// enter initialization mode
RTC_ISR |= RTC_ISR_INIT;
// wait until initialization mode has been entered
while((RTC_ISR & RTC_ISR_INITF) != RTC_ISR_INITF) {
// do nothing
}
RTC_TR = 0; // 00:00:00
RTC_DR = // friday, 01.01.16
(1 << RTC_DR_YT_SHIFT) |
(6 << RTC_DR_YU_SHIFT) |
(5 << RTC_DR_WDU_SHIFT) |
(0 << RTC_DR_MT_SHIFT) |
(1 << RTC_DR_MU_SHIFT) |
(0 << RTC_DR_DT_SHIFT) |
(1 << RTC_DR_DU_SHIFT);
// disable Alarm A
RTC_CR &= ~RTC_CR_ALRAE;
// wait until register is writeable
while((RTC_ISR & RTC_ISR_ALRAWF) != RTC_ISR_ALRAWF) {
// do nothing
}
tmp |= (duration_secs % 10) << RTC_ALRMXR_SU_SHIFT;
duration_secs /= 10;
tmp |= (duration_secs % 6) << RTC_ALRMXR_ST_SHIFT;
duration_secs /= 6;
tmp |= (duration_secs % 10) << RTC_ALRMXR_MNU_SHIFT;
duration_secs /= 10;
tmp |= (duration_secs % 6) << RTC_ALRMXR_MNT_SHIFT;
duration_secs /= 6;
tmp |= (duration_secs % 10) << RTC_ALRMXR_HU_SHIFT;
duration_secs /= 10;
tmp |= (duration_secs % 2) << RTC_ALRMXR_HT_SHIFT;
// FIXME: >1d is not supported
tmp |= RTC_ALRMXR_MSK4; // ignore day/date
// set alarm register
RTC_ALRMAR = tmp;
// clear Alarm A flag
RTC_ISR &= ~RTC_ISR_ALRAF;
// enable RTC alarm interrupt for wakeup
RTC_CR |= RTC_CR_ALRAE | RTC_CR_ALRAIE;
// leave initialization mode
RTC_ISR &= ~RTC_ISR_INIT;
// lock registers again (using invalid key)
lock_rtc_access();
// enter deep sleep mode
SCB_SCR |= SCB_SCR_SLEEPDEEP;
PWR_CR |= PWR_CR_LPDS; // voltage regulator low-power mode
pwr_set_stop_mode();
__WFI();
SCB_SCR &= ~SCB_SCR_SLEEPDEEP; // no deepsleep except in this function
init_clock();
}
#if 0
/* Set up timer to fire freq times per second */
static void init_systick(int freq)
@ -256,6 +382,7 @@ int main(void)
fxp_t CURRENT_OFFSET = fxp_from_float(0.049);
init_clock();
init_rtc();
init_gpio();
init_adc();
init_timer();
@ -514,6 +641,14 @@ int main(void)
nextState = ConvMPP;
}
if(time_in_state > 10000) {
lcd_set_cursor_pos(0, 0);
lcd_send_string("Sleep mode ");
while(lcd_process() == 0); // send everything immediately
deepsleep(10);
time_in_state = 9500; // run the voltage test again
}
break;
default:
@ -598,6 +733,25 @@ int main(void)
sentSomething = 1;
}
if((timebase_ms % 500) == 300) {
debug_send_string("RTC seconds: ");
fxp_format_int((RTC_TR >> RTC_TR_SU_SHIFT) & RTC_TR_SU_MASK, msg);
debug_send_string(msg);
debug_send_string(" - ALRAF: ");
fxp_format_int(RTC_ISR & RTC_ISR_ALRAF, msg);
debug_send_string(msg);
debug_send_string(" - EXTI17: ");
fxp_format_int(exti_get_flag_status(EXTI17), msg);
debug_send_string(msg);
sentSomething = 1;
}
if(sentSomething) {
debug_send_string("\r\n");
sentSomething = 0;
@ -633,6 +787,11 @@ void tim3_isr(void)
}
}
void rtc_isr(void)
{
exti_reset_request(EXTI17);
}
void hard_fault_handler(void)
{
while (1);