// 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;

                HAL_PWR_EnterSLEEPMode(0, PWR_SLEEPENTRY_WFI);

                // 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 3d fix with a decent enough precision

                if( ((gps_getdata()->fixtype == 2) || (gps_getdata()->fixtype == 3)) && gps_getdata()->pdop < 10)

                {

                    // Disable GPS module

                    gps_poweroff();

                    // TODO: Set RTC from GPS time

                    // TODO: Set RTC for countdown to next transmission timeslot!

                    // TODO: Set wspr countdown timer for this transmission!

                    fix_acq_starttime = 0;

                    state = SYSTEM_WSPRTX;

                }

                // If no decent fix in 3 minutes

                else if(HAL_GetTick() - fix_acq_starttime > 60000 * 3)

                {

//                {

            	// If we're after the minute but not more than 2s after the minute, start tx

            	if(HAL_GetTick() >= nextwspr_time)

            	{

            		if(HAL_GetTick() < nextwspr_time + 2000)

            		{

            			volatile double latitude_flt = (double)gps_getdata()->latitude / 10000000.0;

            			volatile double longitude_flt = (double)gps_getdata()->longitude / 10000000.0;

            			volatile uint8_t grid_locator[7];

            			__calc_gridloc(grid_locator, latitude_flt, longitude_flt);

						last_wspr_tx_time = HAL_GetTick();

						wspr_transmit(grid_locator);

						state = SYSTEM_IDLE;

            		}

            		else

            		{

            			// Window was missed, go back to idle, and try again after time delay

						last_wspr_tx_time = HAL_GetTick();

            			state = SYSTEM_IDLE;

            		}

                }

                // Schedule next wakeup (maybe 2mins prior ot timeslot if no osc trim)

                // Next wakeup should enter SYSTEM_GPSACQ state...

            } break;

        }

        if(HAL_GetTick() - led_timer > blink_rate)

        {

            ledpulse();

            led_timer = HAL_GetTick();

        }

        if(statled_ontime && HAL_GetTick() - statled_ontime > 10)

        {

            HAL_GPIO_WritePin(LED_BLUE, 0);

            statled_ontime = 0;

        }

    }

}

    // After wake-up from STOP reconfigure the PLL

    sysclk_init();

}

// Initialize system clocks

void sysclk_init(void)

{

    RCC_OscInitTypeDef RCC_OscInitStruct;

    RCC_ClkInitTypeDef RCC_ClkInitStruct;

    RCC_PeriphCLKInitTypeDef PeriphClkInit;

    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_HSI14|RCC_OSCILLATORTYPE_LSI;

    RCC_OscInitStruct.HSIState = RCC_HSI_ON;

    RCC_OscInitStruct.HSI14State = RCC_HSI14_ON;

    RCC_OscInitStruct.HSICalibrationValue = 16;

    RCC_OscInitStruct.HSI14CalibrationValue = 16;

    RCC_OscInitStruct.LSIState = RCC_LSI_ON;

    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;

    HAL_RCC_OscConfig(&RCC_OscInitStruct);

    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK

                                |RCC_CLOCKTYPE_PCLK1;

    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;

    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

    HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0);

    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USART1|RCC_PERIPHCLK_I2C1;

    PeriphClkInit.Usart1ClockSelection = RCC_USART1CLKSOURCE_SYSCLK; //RCC_USART1CLKSOURCE_PCLK1;

    PeriphClkInit.I2c1ClockSelection = RCC_I2C1CLKSOURCE_SYSCLK;

    PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;

    HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

    HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

    HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

    __SYSCFG_CLK_ENABLE();

    // SysTick_IRQn interrupt configuration

    HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);

}