more accurate names for deep sleep and shallow sleep modes

1 files changed, 80 insertions, 38 deletions

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