power_down... Not really powered down?

MonkeyEnFuego · **Joined:** Wed Mar 23, 2011 9:35 am **Posts:** 54

I am confused. I have my watch app, and it displays for 10 seconds then goes to sleep. The idea is to preserve battery. I had a mental lapse and added code in the main_app_loop() to buzz on the hour and half-hour.

Then I realized, wait a min. I will be asleep. I can't buzz on the hour and half-hour this way (unless I am displaying (unlikely).

The weird thing, is that it appears to work. Now I am confused. When you call:

Code: Select all

pulse_update_power_down_timer(10000);

and go asleep, does it just turn off the display and main_app_loop() is always being called? I figured it wouldn't be. If so, I will restructure the code so short circuit when "asleep".

Any other pointers on preserving battery would be great.

<confused>

Matt

Ryan · **Joined:** Tue Feb 15, 2011 10:35 pm **Posts:** 42

When pulse_update_power_down_timer() is called the screen is turned off and the processor is put into a low power sleep mode. During this time the main_app_loop() function should not be called, which suggests that your watch isn't in sleep mode. Only bluetooth, the alarm and the button can wake up the watch from sleep mode.

Also for your app I'd recommend using the alarm and registering a callback for it to buzz every half hour.

MonkeyEnFuego · **Joined:** Wed Mar 23, 2011 9:35 am **Posts:** 54

You sure? This example buzzes every minute, even when asleep

Code: Select all

static struct pulse_time_tm current_time;

void buzz () {
    pulse_vibe_on();
    pulse_mdelay(100);
    pulse_vibe_off();
}


void polite_buzz () {
    
    // We are confused and must have lost power with no time set
    if (current_time.tm_year < 100) return;
    
    // If it is before 8am or after 10pm, shhh!
    if (current_time.tm_hour < 8 || current_time.tm_hour >= 22) return;
    
    // Otherwise we are good to go
    buzz();
}

void handle_button_causing_wakeup ();

void main_app_init () {
    // Set a timer to go to sleep if we don't hear from anyone
    pulse_update_power_down_timer(10000);
    
    // Register a callback for the woke_from_button event
    pulse_register_callback(ACTION_WOKE_FROM_BUTTON, &handle_button_causing_wakeup);
}

void handle_button_causing_wakeup () {
    
    pulse_blank_canvas();
    pulse_update_power_down_timer(10000);
}

void main_app_handle_button_down() {
}

void main_app_handle_button_up() {
    // Reset any timer to go to sleep
    pulse_update_power_down_timer(10000);

}

void main_app_loop () {
    
    pulse_get_time_date(¤t_time); 
    
    // Let's buzz every 1 minute to make a point
    if (current_time.tm_sec == 0) {
            polite_buzz();           
    }    
    printf("Awake\n");
}


void main_app_handle_doz() {

}


void main_app_handle_hardware_update(enum PulseHardwareEvent event) {

}

Ryan · **Joined:** Tue Feb 15, 2011 10:35 pm **Posts:** 42

While in sleep mode the watch wakes up once a minute to check the alarm. The vibrations occur during these alarm checks.

MonkeyEnFuego · **Joined:** Wed Mar 23, 2011 9:35 am **Posts:** 54

Soooooo... The main_app_loop *IS* called, but only once per minute?

Ryan · **Joined:** Tue Feb 15, 2011 10:35 pm **Posts:** 42

You are correct. In most cases this is not noticeable, but you found one where it was apparent.

MonkeyEnFuego · **Joined:** Wed Mar 23, 2011 9:35 am **Posts:** 54

Is there an easy way to see if you are "looping" while asleep to avoid any computation that is meant for display to help preserve battery. Of course I can manage my own boolean, but just curious if there is a baked in way to do it.

Thanks,

power_down... Not really powered down?

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