path: root/watch-library/watch/watch.h

/// @file watch.h

#ifndef WATCH_H_
#define WATCH_H_
#include <stdint.h>
#include "driver_init.h"
#include "hpl_calendar.h"
#include "hal_ext_irq.h"

/** @mainpage Sensor Watch Documentation
 *  @brief This documentation covers most of the functions you will use to interact with the Sensor Watch
           hardware. It is divided into the following sections:
            - @ref app - This section covers the functions that you will implement in your app.c file when designing a
                         Sensor Watch app.
            - @ref slcd - This section covers functions related to the Segment LCD display driver, which is responsible
                          for displaying strings of characters and indicators on the main watch display.
            - @ref led - This section covers functions related to the bi-color red/green LED mounted behind the LCD.
            - @ref rtc - This section covers functions related to the SAM L22's real-time clock peripheral, including
                         date, time and alarm functions.
            - @ref adc - This section covers functions related to the SAM L22's analog-to-digital converter, as well as
                         configuring and reading values from the three analog-capable pins on the 9-pin connector.
            - @ref buttons - This section covers functions related to the three buttons: Light, Mode and Alarm.
            - @ref gpio - This section covers functions related to general-purpose input and output signals.
            - @ref i2c - This section covers functions related to the SAM L22's built-I2C driver, including configuring
                         the I2C bus, putting values directly on the bus and reading data from registers on I2C devices.
            - @ref deepsleep - This section covers functions related to preparing for and entering BACKUP mode, the
                               deepest sleep mode available on the SAM L22.
 */

/** @addtogroup app Application Framework
  * @brief This section covers the functions that you will implement in your app.c file when designing a Sensor Watch app.
  * @details You should be able to write a watch app by simply implementing these functions and declaring callbacks for
  *          various GPIO and peripheral interrupts. The main.c file takes care of calling these functions for you. The
  *          general flow:
  *
  *            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.
  *               - 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.
  *               - You should definitely set up some interrupts here.
  *            4. The main run loop begins: your app_loop() function is called.
  *               - Run code and update your UI here.
  *               - 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.
  *               - 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.
  *               - After this, execution resumes at (4).
  */
/// @{
/** @brief A function you will implement to initialize your application state. The app_init function is called before
  *        anything else. Use it to set up any internal data structures or application state required by your app,
  *        but don't configure any peripherals just yet.
  */
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.
  */
void app_wake_from_deep_sleep();

/** @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
  *        set up (real-time clock, I2C, etc.) Depending on your application, you may or may not want to configure
  *        sensors on your sensor board here. For example, a low-power accelerometer that will run at all times should
  *        be configured here, whereas you may want to enable a more power-hungry sensor only when you need it.
  * @note If your app enters the ultra-low power BACKUP sleep mode, this function will be called again when it wakes
  *       from that deep sleep state. In this state, the RTC will still be configured with the correct date and time.
  */
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 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,
  *       so e.g. the I2C controller, if configured, will sleep in STANDBY. But you can use it again as soon as your
  *       app wakes up.
  */
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).
 */
void app_prepare_for_sleep();

/** @brief A method you will implement to configure the app after waking from STANDBY sleep mode.
  */
void app_wake_from_sleep();

/// Called by main.c while setting up the app. You should not call this from your app.
void _watch_init();
/// @}


/** @addtogroup slcd Segment LCD Display
  * @brief This section covers functions related to the Segment LCD display driver, which is responsible
  *        for displaying strings of characters and indicators on the main watch display.
  */
/// @{
/** @brief Enables the Segment LCD display.
  * Call this before attempting to set pixels or display strings.
  */
void watch_enable_display();

/** @brief Sets a pixel. Use this to manually set a pixel with a given common and segment number.
  * @param com the common pin, numbered from 0-2.
  * @param seg the segment pin, numbered from 0-23.
  */
void watch_set_pixel(uint8_t com, uint8_t seg);

/** @brief Clears a pixel. Use this to manually clear a pixel with a given common and segment number.
  * @param com the common pin, numbered from 0-2.
  * @param seg the segment pin, numbered from 0-23.
  * Use this to manually set a pixel with a common and a segment number.
  */
void watch_clear_pixel(uint8_t com, uint8_t seg);

/** @brief Displays a string at the given position, starting from the top left. There are ten digits.
           A space in any position will clear that digit.
  * @param string A null-terminated string.
  * @param position The position where you wish to start displaying the string. The day of week digits
  *                 are positions 0 and 1; the day of month digits are positions 2 and 3, and the main
  *                 clock line occupies positions 4-9.
  * @note This method does not clear the display; if for example you display a two-character string at
          position 0, positions 2-9 will retain whatever state they were previously displaying.
  */
void watch_display_string(char *string, uint8_t position);
/// @}


/** @addtogroup led LED Control
  * @brief This section covers functions related to the bi-color red/green LED mounted behind the LCD.
  */
/// @{
/** @brief Enables the LED.
  * @param pwm if true, enables PWM output for brightness control (required to use @ref watch_set_led_color).
               If false, configures the LED pins as digital outputs.
  * @note The TC driver required for PWM mode does not run in STANDBY mode. You should keep your app awake
          while PWM'ing the LED's, and disable them before going to sleep.
  */
void watch_enable_led(bool pwm);

/** @brief Disables the LED.
  * @param pwm if true, disables the PWM output. If false, disables the digital outputs.
  */
void watch_disable_led(bool pwm);

/** @brief Sets the LED to a custom color by modulating each output's duty cycle.
  * @param red The red value.
  * @param green The green value.
  * @note still working on this, 0-65535 works now but these values may change.
  */
void watch_set_led_color(uint16_t red, uint16_t green);
/** @brief Sets the red LED to full brightness, and turns the green LED off.
  */
void watch_set_led_red();

/** @brief Sets the green LED to full brightness, and turns the red LED off. */
void watch_set_led_green();

/** @brief Sets both red and green LEDs to full brightness. */
void watch_set_led_yellow();

/** @brief Sets both red and green LEDs to full brightness. */
void watch_set_led_off();
/// @}


/** @addtogroup rtc Real-Time Clock
  * @brief This section covers functions related to the SAM L22's real-time clock peripheral, including
  *        date, time and alarm functions.
  */
/// @{
/// Called by main.c to check if the RTC is enabled.
bool _watch_rtc_is_enabled();

/** @brief Sets the system date and time.
  * @param date_time A struct representing the date and time you wish to set.
  */
void watch_set_date_time(struct calendar_date_time date_time);

/** @brief Returns the system date and time in the provided struct.
  * @param date_time A pointer to a calendar_date_time struct.
                     It will be populated with the correct date and time on return.
  */
void watch_get_date_time(struct calendar_date_time *date_time);

/** @brief Registers a "tick" callback that will be called once per second.
  * @param callback The function you wish to have called when the clock ticks.
  */
void watch_register_tick_callback(ext_irq_cb_t callback);
/// @}


/** @addtogroup adc Analog Input
  * @brief This section covers functions related to the SAM L22's analog-to-digital converter, as well as
  *        configuring and reading values from the three analog-capable pins on the 9-pin connector.
  */
/// @{
/** @brief Enables the ADC peripheral, and configures the selected pin for analog input.
  * @param pin One of pins A0, A1 or A2.
  */
void watch_enable_analog(const uint8_t pin);
/// @}


/** @addtogroup buttons Buttons
  * @brief This section covers functions related to the three buttons: Light, Mode and Alarm.
  */
/// @{
/** @brief Enables the external interrupt controller.
  */
void watch_enable_buttons();

/** @brief Configures an external interrupt
  * @param pin One of pins BTN_LIGHT, BTN_MODE or BTN_ALARM.
  * @param callback The function you wish to have called when the button is pressed.
  * @todo Make the alarm interrupt use the RTC tamper interrupt instead of the EIC.
  */
void watch_register_button_callback(const uint32_t pin, ext_irq_cb_t callback);
/// @}


/** @addtogroup gpio Digital Input and Output
  * @brief This section covers functions related to general-purpose input and output signals.
  */
/// @{
/** @brief Configures the selected pin for digital input.
  * @param pin The pin that you wish to act as an input.
  */
void watch_enable_digital_input(const uint8_t pin);

/** @brief Enables a pull-up resistor on the selected pin.
  * @param pin The pin that you wish to configure.
  */
void watch_enable_pull_up(const uint8_t pin);

/** @brief Enables a pull-down resistor on the selected pin.
  * @param pin The pin that you wish to configure.
  */
void watch_enable_pull_down(const uint8_t pin);

/** @brief Gets the level of the selected pin.
  * @param pin The pin whose value you wish to read.
  * @return true if the pin was logic high; otherwise, false.
  */
bool watch_get_pin_level(const uint8_t pin);

/** @brief Configures the selected pin for digital output.
  * @param pin The pin that you wish to act as an output.
  */
void watch_enable_digital_output(const uint8_t pin);

/** @brief Disables digital output on the selected pin.
  * @param pin The pin that you wish disable.
  */
void watch_disable_digital_output(const uint8_t pin);

/** @brief Sets the level of the selected pin.
  * @param pin The pin whose value you wish to set.
  * @param level The level you wish to set: true for high, false for low.
  */
void watch_set_pin_level(const uint8_t pin, const bool level);
/// @}


/** @addtogroup i2c I2C Controller Driver
  * @brief This section covers functions related to the SAM L22's built-I2C driver, including
  *        configuring the I2C bus, putting values directly on the bus and reading data from
  *        registers on I2C devices.
  */
/// @{
/** @brief Enables the I2C peripheral. Call this before attempting to interface with I2C devices.
  */
void watch_enable_i2c();

/** @brief Sends a series of values to a device on the I2C bus.
  * @param addr The address of the device you wish to talk to.
  * @param buf A series of unsigned bytes; the data you wish to transmit.
  * @param length The number of bytes in buf that you wish to send.
  */
void watch_i2c_send(int16_t addr, uint8_t *buf, uint16_t length);

/** @brief Receives a series of values from a device on the I2C bus.
  * @param addr The address of the device you wish to hear from.
  * @param buf Storage for the incoming bytes; on return, it will contain the received data.
  * @param length The number of bytes that you wish to receive.
  */
void watch_i2c_receive(int16_t addr, uint8_t *buf, uint16_t length);

/** @brief Writes a byte to a register in an I2C device.
  * @param addr The address of the device you wish to address.
  * @param reg The register on the device that you wish to set.
  * @param data The value that you wish to set the register to.
  */
void watch_i2c_write8(int16_t addr, uint8_t reg, uint8_t data);

/** @brief Reads a byte from a register in an I2C device.
  * @param addr The address of the device you wish to address.
  * @param reg The register on the device that you wish to read.
  * @return An unsigned byte representing the value of the register that was read.
  */
uint8_t watch_i2c_read8(int16_t addr, uint8_t reg);

/** @brief Reads an unsigned little-endian word from a register in an I2C device.
  * @param addr The address of the device you wish to address.
  * @param reg The register on the device that you wish to read.
  * @return An unsigned word representing the value of the register that was read.
  * @note This reads two bytes into the word in bus order. If the device returns
          the LSB first and then the MSB, you can use this value as returned.
          If the device returns the data in big-endian order or uses some other
          kind of fancy bit packing, you may need to shuffle some bits around.
  */
uint16_t watch_i2c_read16(int16_t addr, uint8_t reg);

/** @brief Reads three bytes as an unsigned little-endian int from a register in an I2C device.
  * @param addr The address of the device you wish to address.
  * @param reg The register on the device that you wish to read.
  * @return An unsigned word representing the value of the register that was read.
  * @note This reads three bytes into the word in bus order. If the device returns
          these bytes LSB first, you can use this value as returned. If there is a
          sign bit, the device returns the data in big-endian order, or it uses some
          other kind of fancy bit packing, you may need to shuffle some bits around.
  */
uint32_t watch_i2c_read24(int16_t addr, uint8_t reg);


/** @brief Reads an unsigned little-endian int from a register in an I2C device.
  * @param addr The address of the device you wish to address.
  * @param reg The register on the device that you wish to read.
  * @return An unsigned word representing the value of the register that was read.
  * @note This reads three bytes into the word in bus order. If the device returns
          these bytes LSB first, you can use this value as returned. If the device
          returns the data in big-endian order, or it uses some other kind of fancy
          bit packing, you may need to shuffle some bits around.
  */
uint32_t watch_i2c_read32(int16_t addr, uint8_t reg);
/// @}


/** @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
  */
/// @{
/** @brief Stores 32 bits of data in the RTC's backup register, which retains its data in deep sleep.
  * @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, which retains its data in deep sleep.
  * @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 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.
  * @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.
  * @warning still kind of glitchy!
  */
void watch_enter_deep_sleep();
/// @}

#endif /* WATCH_H_ */