clemente di caprio / KL25Z_RTC

Class for the RTC module.

Dependents:   FRDM_RTC

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  1. Please pay attention

Please pay attention

This library works only with the FRDM board connected to USB via OpenSDA connector The OpenSDA chip has a pin connected, via the resistor R24, to the KL25Z CLOCKIN pin. So this is why it works.

If you use the board alone, you must configure the MCU in a different manner. I follow the instruction in this link: https://community.freescale.com/docs/DOC-94734 but without success.

This is the code I added for testing purpose:

Initialization code for RTC use

    // Enable the internal reference clock. MCGIRCLK is active.
    MCG->C1 |= MCG_C1_IRCLKEN_MASK;
    // Select the slow internal reference clock source.
    MCG->C2 &= ~(MCG_C2_IRCS_MASK);
    // Set PTC1 as RTC_CLKIN and select 32 KHz clock source for the RTC module.
    PORTC->PCR[1] &= ~PORT_PCR_MUX_MASK;
    PORTC->PCR[1] = PORT_PCR_MUX(1);    
    SIM->SOPT1 &= ~SIM_SOPT1_OSC32KSEL_MASK;
    SIM->SOPT1 |= SIM_SOPT1_OSC32KSEL(2);
    // Set PTC3 as CLKOUT pin and selects the MCGIRCLK clock to output on the CLKOUT pin.
    SIM->SOPT2 |= SIM_SOPT2_CLKOUTSEL(0x4);
    PORTC->PCR[3] |= (PORT_PCR_MUX(0x5));
    
    // enable RTC clock
    SIM->SCGC6 |= SIM_SCGC6_RTC_MASK;
    RTC->CR = RTC_CR_SWR_MASK;
    RTC->CR &= ~RTC_CR_SWR_MASK;
    
    if (RTC->SR & RTC_SR_TIF_MASK){
         RTC->TSR = 0x00000000;
    }    
    RTC->TCR = RTC_TCR_CIR(1) | RTC_TCR_TCR(0xFF);

    ecc...

I build this class around the rtc api available from mbed. I just added user call back function and the alarm setting.

The demo software use two function to put the MCU in sleep or deepsleep. The MCU will restart for the RTC IRQ.

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