enum _state

{

    SYSTEM_IDLE = 0, // awaiting RTC interrupt for wakeup TODO wake up before scheduled time to get fix?

    SYSTEM_GPSACQ, // RTC interrupted

    SYSTEM_WSPRTX, // Wait for timeslot and actually transmit the message

};

int main(void)

{

    HAL_Init();

    sysclk_init();

    gpio_init();

    adc_init();

    i2c_init();

    wspr_init();

    uint32_t led_timer = HAL_GetTick();

    led_blink(4);

    uint16_t blink_rate = BLINK_FAST;

    uint8_t state = SYSTEM_GPSACQ;

    uint32_t gps_polltimer = 0;

    uint32_t fix_acq_starttime = 0;

    uint32_t nextwspr_time = 0;

    uint32_t last_wspr_tx_time = 0;

    uint8_t fix_ok = 0;

    uint8_t numsats = 0;

    while (1)

    {

    	// Every 10 minutes, wake up and try to wspr

    	if(HAL_GetTick() - last_wspr_tx_time > 60000 * 10)

    	{

    		state = SYSTEM_GPSACQ;

    	}

        // Update fix status every 2 seconds

        if(HAL_GetTick() - gps_polltimer > 2000)

        {

            if(gps_ison())

            {

            	gps_update_data();

            	// If odd minute

            	if(gps_getdata()->minute % 2)

            	{

            		// Wait until even minute, coming soon

            		nextwspr_time = HAL_GetTick() + (60000 - (gps_getdata()->second * 1000));

            	}

            	// If even minute

            	else

            	{

            		// Wait until odd minute, one minute and some change away

            		nextwspr_time = HAL_GetTick() + 60000 + (60000 - (gps_getdata()->second * 1000));

            	}

            }

            gps_polltimer = HAL_GetTick();

        }

        switch(state)

        {

            // Idling: sleep and wait for RTC timeslot trigger

            case SYSTEM_IDLE:

            {

                blink_rate = BLINK_SLOW;

                // Wait for RTC wakeup interrupt

                //wfi();

                //enter_sleep();

                // Somehow go to another state when we get an interrupt

//                state = SYSTEM_GPSACQ;

            } break;

            // Attempt to acquire GPS fix

            case SYSTEM_GPSACQ:

            {

                blink_rate = BLINK_FAST;

                if(!gps_ison())

                {

                	fix_acq_starttime = HAL_GetTick();

                    gps_poweron(); // power on and initialize GPS module

                }

                if(gps_getdata()->fixtype > 0 && gps_getdata()->pdop < 5)

                {

                    // Disable GPS module

                    gps_poweroff();