more accurate names for deep sleep and shallow sleep modes

6 files changed, 133 insertions, 80 deletions

diff --git a/watch-library/main.c b/watch-library/main.c
index db602a34..1fe751ef 100755
--- a/watch-library/main.c
+++ b/watch-library/main.c
@@ -57,7 +57,7 @@ int main(void) {
     // Ideally we should check if the TAMPER or CMP0 (alarm) flags are set.
     if (_watch_rtc_is_enabled()) {
         // User code. Give the application a chance to restore state from backup registers.
-        app_wake_from_deep_sleep();
+        app_wake_from_backup();
 
         // disable the tamper interrupt and clear the tamper bit
         hri_rtcmode0_clear_INTEN_TAMPER_bit(RTC);
@@ -75,9 +75,9 @@ int main(void) {
         bool can_sleep = app_loop();
 
         if (can_sleep && !usb_enabled) {
-            app_prepare_for_sleep();
+            app_prepare_for_standby();
             sleep(4);
-            app_wake_from_sleep();
+            app_wake_from_standby();
         }
     }
 
diff --git a/watch-library/watch/watch_app.h b/watch-library/watch/watch_app.h
index 00a6a610..56b9bfd3 100644
--- a/watch-library/watch/watch_app.h
+++ b/watch-library/watch/watch_app.h
@@ -33,7 +33,7 @@
   *
   *            1. Your app_init() function is called.
   *               - This method should only be used to set your initial application state.
-  *            2. If your app is waking from BACKUP, app_wake_from_deep_sleep()  is called.
+  *            2. If your app is waking from BACKUP, app_wake_from_backup() is called.
   *               - If you saved state in the RTC's backup registers, you can restore it here.
   *            3. Your app_setup() method is called.
   *               - You may wish to enable some functionality and peripherals here.
@@ -43,11 +43,11 @@
   *               - Return true if your app is prepared to enter STANDBY mode.
   *            5. This step differs depending on the value returned by app_loop:
   *               - If you returned false, execution resumes at (4).
-  *               - If you returned true, app_prepare_for_sleep() is called; execution moves on to (6).
-  *            6. The microcontroller enters the STANDBY sleep mode.
+  *               - If you returned true, app_prepare_for_standby() is called; execution moves on to (6).
+  *            6. The microcontroller enters STANDBY mode.
   *               - No user code will run, and the watch will enter a low power mode.
   *               - The watch will remain in this state until an interrupt wakes it.
-  *            7. Once woken from STANDBY, your app_wake_from_sleep() function is called.
+  *            7. Once woken from STANDBY, your app_wake_from_standby() function is called.
   *               - After this, execution resumes at (4).
   */
 /// @{
@@ -57,11 +57,11 @@
   */
 void app_init();
 
-/** @brief A function you will implement to wake from deep sleep mode. The app_wake_from_deep_sleep function is only
-  *        called if your app is waking from the ultra-low power BACKUP sleep mode. You may have chosen to store some
-  *        state in the RTC's backup registers prior to entering this mode. You may restore that state here.
+/** @brief A function you will implement to wake from BACKUP mode, which wipes the system's RAM, and with it, your
+  *        application's state. You may have chosen to store some important application state in the RTC's backup
+  *        registers prior to entering this mode. You may restore that state here.
   */
-void app_wake_from_deep_sleep();
+void app_wake_from_backup();
 
 /** @brief A function you will implement to set up your application. The app_setup function is like setup() in Arduino.
   *        It is called once when the program begins. You should set pin modes and enable any peripherals you want to
@@ -74,12 +74,12 @@ void app_wake_from_deep_sleep();
 void app_setup();
 
 /** @brief A function you will implement to serve as the app's main run loop. This method will be called repeatedly,
-           or if you enter STANDBY sleep mode, as soon as the device wakes from sleep.
-  * @return You should return true if your app is prepared to enter STANDBY sleep mode. If you return false, your
-  *         app's app_loop method will be called again immediately. Note that in STANDBY mode, the watch will consume
-  *         only about 95 microamperes of power, whereas if you return false and keep the app awake, it will consume
-  *         about 355 microamperes. This is the difference between months of battery life and days. As much as
-  *         possible, you should limit the amount of time your app spends awake.
+           or if you enter STANDBY mode, as soon as the device wakes from sleep.
+  * @return You should return true if your app is prepared to enter STANDBY mode. If you return false, your app's
+  *         app_loop method will be called again immediately. Note that in STANDBY mode, the watch will consume only
+  *         about 95 microamperes of power, whereas if you return false and keep the app awake, it will consume about
+  *         355 microamperes. This is the difference between months of battery life and days. As much as possible,
+  *         you should limit the amount of time your app spends awake.
   * @note Only the RTC, the segment LCD controller and the external interrupt controller run in STANDBY mode. If you
   *       are using, e.g. the PWM function to set a custom LED color, you should return false here until you are
   *       finished with that operation. Note however that the peripherals will continue running after waking up,
@@ -88,21 +88,21 @@ void app_setup();
   */
 bool app_loop();
 
-/** @brief A function you will implement to prepare to enter STANDBY sleep mode. The app_prepare_for_sleep function is
- *         called before the watch goes into the STANDBY sleep mode. In STANDBY mode, most peripherals are shut down,
- *         and no code will run until the watch receives an interrupt (generally either the 1Hz tick or a press on one
- *         of the buttons).
+/** @brief A function you will implement to prepare to enter STANDBY mode. The app_prepare_for_standby function is
+ *         called after your app_loop function returns true, and just before the watch enters STANDBY mode. In this
+ *         mode most peripherals are shut down, and no code will run until the watch receives an interrupt (generally
+ *         either the 1Hz tick or a press on one of the buttons).
  * @note If you are PWM'ing the LED or playing a sound on the buzzer, the TC/TCC peripherals that drive those operations
  *       will not run in STANDBY. BUT! the output pins will retain the state they had when entering standby. This means
  *       you could end up entering standby with an LED on and draining power, or with a DC potential across the piezo
  *       buzzer that could damage it if left in this state. If your app_loop does not prevent sleep during these
- *       activities, you should make sure to disable these outputs in app_prepare_for_sleep.
+ *       activities, you should make sure to disable these outputs in app_prepare_for_standby.
  */
-void app_prepare_for_sleep();
+void app_prepare_for_standby();
 
-/** @brief A method you will implement to configure the app after waking from STANDBY sleep mode.
+/** @brief A method you will implement to configure the app after waking from STANDBY mode.
   */
-void app_wake_from_sleep();
+void app_wake_from_standby();
 
 /// @}
 #endif
diff --git a/watch-library/watch/watch_deepsleep.c b/watch-library/watch/watch_deepsleep.c
index 9ca53db0..8120617b 100644
--- a/watch-library/watch/watch_deepsleep.c
+++ b/watch-library/watch/watch_deepsleep.c
@@ -151,12 +151,7 @@ void _watch_disable_all_peripherals_except_slcd() {
     MCLK->APBCMASK.reg &= ~MCLK_APBCMASK_SERCOM3;
 }
 
-void watch_enter_shallow_sleep(bool display_on) {
-    if (!display_on) {
-        slcd_sync_deinit(&SEGMENT_LCD_0);
-        hri_mclk_clear_APBCMASK_SLCD_bit(SLCD);
-    }
-
+void watch_enter_sleep_mode() {
     // disable all other peripherals
     _watch_disable_all_peripherals_except_slcd();
 
@@ -178,15 +173,19 @@ void watch_enter_shallow_sleep(bool display_on) {
     // call app_setup so the app can re-enable everything we disabled.
     app_setup();
 
-    // and call app_wake_from_sleep (since main won't have a chance to do it)
-    app_wake_from_sleep();
+    // and call app_wake_from_standby (since main won't have a chance to do it)
+    app_wake_from_standby();
 }
 
-void watch_enter_deep_sleep() {
-    // this will not work on the current silicon revision, but I said in the documentation that we do it.
-    // so let's do it!
-    watch_register_extwake_callback(BTN_ALARM, NULL, true);
+void watch_enter_deep_sleep_mode() {
+    // identical to sleep mode except we disable the LCD first.
+    slcd_sync_deinit(&SEGMENT_LCD_0);
+    hri_mclk_clear_APBCMASK_SLCD_bit(SLCD);
+
+    watch_enter_sleep_mode();
+}
 
+void watch_enter_backup_mode() {
     watch_rtc_disable_all_periodic_callbacks();
     _watch_disable_all_peripherals_except_slcd();
     slcd_sync_deinit(&SEGMENT_LCD_0);
@@ -196,3 +195,15 @@ void watch_enter_deep_sleep() {
     // go into backup sleep mode (5). when we exit, the reset controller will take over.
     sleep(5);
 }
+
+// deprecated
+void watch_enter_shallow_sleep(bool display_on) {
+    if (display_on) watch_enter_sleep_mode();
+    else watch_enter_deep_sleep_mode();
+}
+
+// deprecated
+void watch_enter_deep_sleep() {
+    watch_register_extwake_callback(BTN_ALARM, NULL, true);
+    watch_enter_backup_mode();
+}
diff --git a/watch-library/watch/watch_deepsleep.h b/watch-library/watch/watch_deepsleep.h
index 84825f00..a453e763 100644
--- a/watch-library/watch/watch_deepsleep.h
+++ b/watch-library/watch/watch_deepsleep.h
@@ -32,26 +32,54 @@ extern ext_irq_cb_t btn_alarm_callback;
 extern ext_irq_cb_t a2_callback;
 extern ext_irq_cb_t a4_callback;
 
-/** @addtogroup deepsleep Deep Sleep Control
-  * @brief This section covers functions related to preparing for and entering BACKUP mode, the
-  *        deepest sleep mode available on the SAM L22
+/** @addtogroup deepsleep Sleep Control
+  * @brief This section covers functions related to the various sleep modes available to the watch,
+  *        including Sleep, Deep Sleep, and BACKUP mode.
+  * @details These terms changed meaning a bit over the course of development; if you are coming
+  *          to this documentation after having worked with an earlier version of the library,
+  *          these definitions should clarify the terminology. Terms in all caps are modes of the
+  *          SAM L22; terms in Title Case are specific implementations in this library.
+  *           - ACTIVE mode is the mode the SAM L22 is in when both the main clock and the CPU are
+  *             running. It is the most power-hungry mode. If you ever call delay_ms to wait a beat,
+  *             the watch will remain in ACTIVE mode while taking that delay. In addition, whenever
+  *             your `app_loop` function returns false, the device will remain in ACTIVE mode and
+  *             call your `app_loop` function again.
+  *           - STANDBY mode turns off the main clock and halts the CPU. Since the PWM driver is
+  *             run from the main clock, it also stops the buzzer and any dimming of the LEDs.
+  *             In this mode, the watch can wake from any interrupt source. Whenever your `app_loop`
+  *             function returns true, the watch enters STANDBY mode until the next tick or other
+  *             interrupt. This mode uses much less power than ACTIVE mode.
+  *           - Sleep Mode is a special case of STANDBY mode. In this mode, the watch turns off
+  *             almost all peripherals (including the external interrupt controller), and disables
+  *             all pins except for the external wake pins. In this mode the watch can only wake
+  *             from the RTC alarm interrupt or an external wake pin (A2, A4 or the alarm button),
+  *             but the display remains on and your app's state is retained. You can enter this
+  *             mode by calling `watch_enter_sleep_mode`. It consumes an order of magnitude less
+  *             power than STANDBY mode.
+  *           - Deep Sleep Mode is identical to sleep mode, but it also turns off the LCD to save
+  *             a bit more power. You can enter this mode by calling `watch_enter_deep_sleep_mode`.
+  *           - BACKUP mode is the lowest possible power mode on the SAM L22. It turns off all pins
+  *             and peripherals except for the RTC. It also turns off the RAM, obliterating your
+  *             application's state. The only way to wake from this mode is by setting an external
+  *             wake interrupt on pin A2 or pin A4, and when you do wake it will be much like a
+  *             wake from reset. You can enter this mode by calling `watch_enter_backup_mode`.
   */
 /// @{
 
 /** @brief Registers a callback on one of the RTC's external wake pins, which can wake the device
-  *        from deep sleep (aka BACKUP) mode.
+  *        from Sleep, Deep Sleep and BACKUP modes (but see warning re: BACKUP mode).
   * @param pin Either pin BTN_ALARM, A2, or A4. These are the three external wake pins. If the pin
   *            is BTN_ALARM, this function also enables an internal pull down on that pin.
-  * @param callback The callback to be called if this pin triggers outside of deep sleep mode. If
-  *                 this is NULL, no callback will be called even in normal mode, but the interrupt
-  *                 will still be enabled so that it can wake from deep sleep or backup mode.
+  * @param callback The callback to be called if this pin triggers outside of BACKUP mode. If this is
+  *                 NULL, no callback will be called even in normal modes, but the interrupt will
+  *                 still be enabled so that it can wake the device.
   * @param level The level you wish to scan for: true for rising, false for falling. Note that you
   *              cannot scan for both rising and falling edges like you can with the external interrupt
   *              pins; with the external wake interrupt, you can only get one or the other.
-  * @note When in normal or STANDBY mode, this will function much like a standard external interrupt
-  *       situation: these pins will wake from standby, and your callback will be called. However,
-  *       if the device enters deep sleep and one of these pins wakes the device, your callback
-  *       WILL NOT be called, as the device is basically waking from reset at that point.
+  * @note When in ACTIVE, STANDBY and Sleep / Deep sleep modes, this will function much like a standard
+  *       external interrupt situation: these pins will wake the device, and your callback will be
+  *       called. However, if the device enters BACKUP mode and one of these pins wakes the device, your
+  *       callback WILL NOT be called, as the device is basically waking from reset at that point.
   * @warning As of the current SAM L22 silicon revision (rev B), the BTN_ALARM pin cannot wake the
   *          device from BACKUP mode. You can still use this function to register a BTN_ALARM interrupt
   *          in normal or deep sleep mode, but to wake from BACKUP, you will need to use pin A2 or A4.
@@ -59,59 +87,73 @@ extern ext_irq_cb_t a4_callback;
 void watch_register_extwake_callback(uint8_t pin, ext_irq_cb_t callback, bool level);
 
 /** @brief Unregisters the RTC interrupt on one of the EXTWAKE pins. This will prevent a value change on
-  *        one of these pins from waking the device from shallow and deep sleep modes.
+  *        one of these pins from waking the device.
   * @param pin Either pin BTN_ALARM, A2, or A4. If the pin is BTN_ALARM, this function DOES NOT disable
   *            the internal pull down on that pin.
   */
 void watch_disable_extwake_interrupt(uint8_t pin);
 
-/** @brief Stores data in one of the RTC's backup registers, which retain their data in deep sleep mode.
+/** @brief Stores data in one of the RTC's backup registers, which retain their data in BACKUP mode.
   * @param data An unsigned 32 bit integer with the data you wish to store.
   * @param reg A register from 0-7.
   */
 void watch_store_backup_data(uint32_t data, uint8_t reg);
 
-/** @brief Gets 32 bits of data from the RTC's backup register.
+/** @brief Gets 32 bits of data from the RTC's BACKUP register.
   * @param reg A register from 0-7.
   * @return An unsigned 32 bit integer with the from the backup register.
   */
 uint32_t watch_get_backup_data(uint8_t reg);
 
-/** @brief Enters a shallow sleep mode by disabling all pins and peripherals except the RTC and (optionally)
-  *        the LCD. You can wake from this mode by pressing the ALARM button, if you have an registered an
-  *        external wake callback on the ALARM button. When your app wakes from this shallow sleep mode, your
-  *        app_setup method will be called, since this function will have disabled things you set up.
-  * @param display_on if true, leaves the LCD on to display whatever content was on-screen. If false, disables
-  *                   the segment LCD controller for additional power savings.
-  * @details This shallow sleep mode is not the lowest power mode available (see watch_enter_deep_sleep), but
-  *          it has the benefit of retaining your application state and being able to wake from the ALARM button.
-  *          It also provides an option for displaying a message to the user when asleep. Note that whether you
-  *          want to wake from the ALARM button, the A2 RTC interrupt or the A4 interrupt, you must configure
-  *          this by calling watch_register_extwake_callback first.
+/** @brief enters Sleep Mode by disabling all pins and peripherals except the RTC and the LCD.
+  * @details This sleep mode is not the lowest power mode available, but it has the benefit of allowing you
+  *          to display a message to the user while asleep. You can also set an alarm interrupt to wake at a
+  *          configfurable interval (every minute, hour or day) to update the display. You can wake from this
+  *          mode by pressing the ALARM button, if you registered an extwake callback on the ALARM button.
+  *          Also note that when your app wakes from this sleep mode, your app_setup method will be called
+  *          again, since this function will have disabled things you set up there.
   *
-  *          Power consumption in shallow sleep mode varies a bit with the battery voltage and the temperature,
-  *          but at 3 V and 25~30° C you can roughly estimate:
-  *           * < 12µA current draw with the LCD controller on
-  *           * < 6µA current draw with the LCD controller off
+  *          Note that to wake from either the ALARM button, the A2 interrupt or the A4 interrupt, you
+  *          must first configure this by calling watch_register_extwake_callback.
+  *
+  *          You can estimate the power consumption of this mode to be on the order of 30 microwatts
+  *          (about 10 µA at 3 V).
   */
-void watch_enter_shallow_sleep(bool display_on);
+void watch_enter_sleep_mode();
+
+/** @brief enters Deep Sleep Mode by disabling all pins and peripherals except the RTC.
+  * @details Short of BACKUP mode, this is the lowest power mode you can enter while retaining your
+  *          application state (and the ability to wake with the alarm button). Just note that the display
+  *          will be completely off, so you should document to the user of your application that they will
+  *          need to press the alarm button to wake the device, or use a sensor board with support for
+  *          an external wake pin.
+  *
+  *          All notes from watch_enter_sleep_mode apply here, except for power consumption. You can estimate
+  *          the power consumption of this mode to be on the order of 12 microwatts (about 4µA at 3 V).
+  */
+void watch_enter_deep_sleep_mode();
 
 /** @brief Enters the SAM L22's lowest-power mode, BACKUP.
-  * @details This function does some housekeeping before entering BACKUP mode. It first disables all
-  *          peripherals except for the RTC, and disables the tick interrupt (since that would wake
-  *          us up from deep sleep). It also sets an external wake source on the ALARM button, if one
-  *          was not already set. If you wish to wake from another source, such as one of the external
-  *          wake interrupt pins on the 9-pin connector, set that up prior to calling this function.
+  * @details This function does some housekeeping before entering BACKUP mode. It first disables all pins
+  *          and peripherals except for the RTC, and disables the tick interrupt (since that would wake
+  *          us up from BACKUP mode). Once again, if you wish to wake from the A2 or the A4 interrupt,
+  *          you must first configure this by calling watch_register_extwake_callback.
   * @note If you have a callback set for an external wake interrupt, it will be called if triggered while
-  *       in ACTIVE, IDLE or STANDBY modes, but it *will not be called* when waking from BACKUP.
-  *       Waking from backup is effectively like waking from reset, except that your @ref
-  *       app_wake_from_deep_sleep function will be called.
+  *       in ACTIVE, STANDBY, Sleep and Deep Sleep modes, but it *will not be called* when waking from
+  *       BACKUP mode. Waking from backup is effectively like waking from reset, except that your
+  *       @ref app_wake_from_backup function will be called.
   * @warning On current revisions of the SAM L22 silicon, the ALARM_BTN pin (PA02 RTC/IN2) cannot wake
   *          the device from deep sleep mode. There is an errata note (Reference: 15010) that says that
   *          due to a silicon bug, RTC/IN2 is not functional in BACKUP. As a result, you should not call
   *          this function unless you have a device on the nine-pin connector with an external interrupt
   *          on pin A2 or A4 (i.e. an accelerometer with an interrupt pin).
   */
+void watch_enter_backup_mode();
+
+__attribute__((deprecated("Use watch_enter_sleep_mode or watch_enter_deep_sleep_mode instead")))
+void watch_enter_shallow_sleep(bool display_on);
+
+__attribute__((deprecated("Use watch_enter_backup_mode instead")))
 void watch_enter_deep_sleep();
 /// @}
 #endif
diff --git a/watch-library/watch/watch_rtc.h b/watch-library/watch/watch_rtc.h
index 1776a712..7ddd7483 100644
--- a/watch-library/watch/watch_rtc.h
+++ b/watch-library/watch/watch_rtc.h
@@ -88,8 +88,8 @@ watch_date_time watch_rtc_get_date_time();
   * @param alarm_time The time that you wish to match. The date is currently ignored.
   * @param mask One of the values in watch_rtc_alarm_match indicating which values to check.
   * @details The alarm interrupt is a versatile tool for scheduling events in the future, especially since it can
-  *          wake the device from both shallow and deep sleep modes. The key to its versatility is the mask
-  *          parameter. Suppose we set an alarm for midnight, 00:00:00.
+  *          wake the device from all sleep modes. The key to its versatility is the mask parameter.
+  *          Suppose we set an alarm for midnight, 00:00:00.
   *           * if mask is ALARM_MATCH_SS, the alarm will fire every minute when the clock ticks to seconds == 0.
   *           * with ALARM_MATCH_MMSS, the alarm will once an hour, at the top of each hour.
   *           * with ALARM_MATCH_HHMMSS, the alarm will fire at midnight every day.
diff --git a/watch-library/watch/watch_slcd.h b/watch-library/watch/watch_slcd.h
index 724d3dde..abe4d744 100644
--- a/watch-library/watch/watch_slcd.h
+++ b/watch-library/watch/watch_slcd.h
@@ -110,7 +110,7 @@ void watch_clear_all_indicators();
 /** @brief Blinks a single character in position 7. Does not affect other positions.
   * @details Six of the seven segments in position 7 (and only position 7) are capable of autonomous
   *          blinking. This blinking does not require any CPU resources, and will continue even in
-  *          standby and shallow sleep mode (if the LCD remains on).
+  *          STANDBY and Sleep mode (but not Deep Sleep mode, since that mode turns off the LCD).
   * @param character The character you wish to blink.
   * @param duration The duration of the on/off cycle in milliseconds, from 50 to ~4250 ms.
   * @note Segment B of position 7 cannot blink autonomously, so not all characters will work well.
@@ -132,8 +132,8 @@ void watch_stop_blink();
   *          or backward in a shift register whose positions map to fixed segments on the LCD. Given
   *          this constraint, an animation across all six segments does not make sense; so the watch
   *          library offers only a simple "tick/tock" in segments D and E. This animation does not
-  *          require any CPU resources, and will continue even in standby and shallow sleep mode
-  *          (if the LCD remains on).
+  *          require any CPU resources, and will continue even in STANDBY and Sleep mode (but not Deep
+  *          Sleep mode, since that mode turns off the LCD).
   * @param duration The duration of each frame in ms. 500 milliseconds produces a classic tick/tock.
   */
 void watch_start_tick_animation(uint32_t duration);