thinking through deep sleep stuff

watch-library/main.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2021, Joey Castillo
- * SAML22 starter project is Copyright (c) 2014-2017, Alex Taradov <alex@taradov.com>
+ * UART methods are Copyright (c) 2014-2017, Alex Taradov <alex@taradov.com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -82,26 +82,35 @@ void uart_puts(char *s) {
     while (*s) uart_putc(*s++);
 }
 
-//-----------------------------------------------------------------------------
-static void sys_init(void) {
-    uart_puts("init_mcu\n");
-    init_mcu();
-    uart_puts("watch_init\n");
-    watch_init();
-    uart_puts("app_init\n");
-    app_init();
-}
-
-//-----------------------------------------------------------------------------
 int main(void) {
+    // Temporary, for debugging.
     uart_init(115200);
-    sys_init();
+
+    // ASF code. Initialize the MCU with configuration options from Atmel Studio.
+    init_mcu();
+
+    // User code. Give the app a chance to initialize its data structures and state.
+    app_init();
+
+    // At this point, if the RTC peripheral is enabled, we are waking from BACKUP.
+    if (watch_rtc_is_enabled()) {
+        // User code. Give the application a chance to restore state from backup registers.
+        app_wake_from_deep_sleep();
+    }
+
+    // Watch library code. Set initial parameters for the device and enable the RTC.
+    watch_init();
+
+    // User code. Give the app a chance to enable and set up peripherals.
+    app_setup();
 
     while (1) {
-        app_loop();
-        app_prepare_for_sleep();
-        sleep(4);
-        app_wake_from_sleep();
+        bool can_sleep = app_loop();
+        if (can_sleep) {
+            app_prepare_for_sleep();
+            sleep(4);
+            app_wake_from_sleep();
+        }
     }
 
     return 0;

watch-library/watch/watch.c

@@ -1,15 +1,8 @@
-/*
- * watch.c
- *
- * Created: 4/25/2021 10:22:10 AM
- *  Author: joeycastillo
- */
-
 #include "watch.h"
 #include <stdlib.h>
 
 void watch_init() {
-    // use switching regulator
+    // Use switching regulator for lower power consumption.
     SUPC->VREG.bit.SEL = 1;
     while(!SUPC->STATUS.bit.VREGRDY);
 
@@ -17,9 +10,8 @@ void watch_init() {
     CALENDAR_0_init();
     calendar_enable(&CALENDAR_0);
 
-    // TODO: use performance level 0?
-//    _set_performance_level(0);
-//    hri_pm_write_PLCFG_PLDIS_bit(PM, true);
+    // Not sure if this belongs in every app -- is there a power impact?
+    delay_driver_init();
 }
 
 static const uint8_t Character_Set[] =
@@ -258,6 +250,10 @@ void watch_set_led_off() {
     }
 }
 
+bool watch_rtc_is_enabled() {
+    return RTC->MODE0.CTRLA.bit.ENABLE;
+}
+
 void watch_set_date_time(struct calendar_date_time date_time) {
     calendar_set_date(&CALENDAR_0, &date_time.date);
     calendar_set_time(&CALENDAR_0, &date_time.time);
@@ -314,7 +310,7 @@ void watch_enable_pull_down(const uint8_t pin) {
     gpio_set_pin_pull_mode(pin, GPIO_PULL_DOWN);
 }
 
-bool watch_get_pin_level(const uint8_t pin, const bool level) {
+bool watch_get_pin_level(const uint8_t pin) {
     return gpio_get_pin_level(pin);
 }
 
@@ -348,3 +344,23 @@ void watch_i2c_receive(int16_t addr, uint8_t *buf, uint16_t length) {
     i2c_m_sync_set_slaveaddr(&I2C_0, addr, I2C_M_SEVEN);
     io_read(I2C_0_io, buf, length);
 }
+
+void watch_store_backup_data(uint32_t data, uint8_t reg) {
+    if (reg < 8) {
+        RTC->MODE0.BKUP[reg].reg = data;
+    }
+}
+
+uint32_t watch_get_backup_data(uint8_t reg) {
+    if (reg < 8) {
+        return RTC->MODE0.BKUP[reg].reg;
+    }
+
+    return 0;
+}
+
+void watch_enter_deep_sleep(){
+    // Not yet implemented.
+    // TODO: enable tamper interrupt on ALARM pin.
+    // sleep(5);
+}

watch-library/watch/watch.h

@@ -1,55 +1,52 @@
-/*
- * Watch.h
- *
- * Created: 4/25/2021 8:29:16 AM
- *  Author: joeycastillo
- */ 
-
-
-#ifndef WATCH_H_
-#define WATCH_H_
-#include <stdint.h>
-#include "driver_init.h"
-#include "hpl_calendar.h"
-#include "hal_ext_irq.h"
-
-void watch_init();
-
-void watch_enable_display();
-void watch_display_pixel(uint8_t com, uint8_t seg);
-void watch_display_string(char *string, uint8_t position);
-
-void watch_enable_led(bool pwm);
-void watch_disable_led(bool pwm);
-void watch_set_led_color(uint16_t red, uint16_t green);
-void watch_set_led_red();
-void watch_set_led_green();
-void watch_set_led_yellow();
-void watch_set_led_off();
-
-void watch_set_date_time(struct calendar_date_time date_time);
-void watch_get_date_time(struct calendar_date_time *date_time);
-
-void watch_enable_tick_callback(ext_irq_cb_t callback);
-
-void watch_enable_analog(const uint8_t pin);
-
-void watch_enable_buttons();
-void watch_register_button_callback(const uint32_t pin, ext_irq_cb_t callback);
-
-void watch_enable_digital_input(const uint8_t pin);
-void watch_enable_pull_up(const uint8_t pin);
-void watch_enable_pull_down(const uint8_t pin);
-bool watch_get_pin_level(const uint8_t pin, const bool level);
-
-void watch_enable_digital_output(const uint8_t pin);
-void watch_disable_digital_output(const uint8_t pin);
-void watch_set_pin_level(const uint8_t pin, const bool level);
-
-struct io_descriptor *I2C_0_io;
-
-void watch_enable_i2c();
-void watch_i2c_send(int16_t addr, uint8_t *buf, uint16_t length);
-void watch_i2c_receive(int16_t addr, uint8_t *buf, uint16_t length);
-
+#ifndef WATCH_H_
+#define WATCH_H_
+#include <stdint.h>
+#include "driver_init.h"
+#include "hpl_calendar.h"
+#include "hal_ext_irq.h"
+
+void watch_init();
+
+void watch_enable_display();
+void watch_display_pixel(uint8_t com, uint8_t seg);
+void watch_display_string(char *string, uint8_t position);
+
+void watch_enable_led(bool pwm);
+void watch_disable_led(bool pwm);
+void watch_set_led_color(uint16_t red, uint16_t green);
+void watch_set_led_red();
+void watch_set_led_green();
+void watch_set_led_yellow();
+void watch_set_led_off();
+
+bool watch_rtc_is_enabled();
+void watch_set_date_time(struct calendar_date_time date_time);
+void watch_get_date_time(struct calendar_date_time *date_time);
+
+void watch_enable_tick_callback(ext_irq_cb_t callback);
+
+void watch_enable_analog(const uint8_t pin);
+
+void watch_enable_buttons();
+void watch_register_button_callback(const uint32_t pin, ext_irq_cb_t callback);
+
+void watch_enable_digital_input(const uint8_t pin);
+void watch_enable_pull_up(const uint8_t pin);
+void watch_enable_pull_down(const uint8_t pin);
+bool watch_get_pin_level(const uint8_t pin);
+
+void watch_enable_digital_output(const uint8_t pin);
+void watch_disable_digital_output(const uint8_t pin);
+void watch_set_pin_level(const uint8_t pin, const bool level);
+
+struct io_descriptor *I2C_0_io;
+
+void watch_enable_i2c();
+void watch_i2c_send(int16_t addr, uint8_t *buf, uint16_t length);
+void watch_i2c_receive(int16_t addr, uint8_t *buf, uint16_t length);
+
+void watch_store_backup_data(uint32_t data, uint8_t reg);
+uint32_t watch_get_backup_data(uint8_t reg);
+void watch_enter_deep_sleep();
+
 #endif /* WATCH_H_ */