Flextimer on K60, capture rising edge

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Flextimer on K60, capture rising edge

1,584 Views
Futte
Contributor II

Hi i am trying to capture rising edge with a flextimer. I wont to calculate the time from one rising edge to the next one. I am trying in this way:

void initFlexTimer()

{

  unsigned int irPort;

  //Port initialisering

  definePort();

  fnDebugMsg("IR\n");

  irPort = _READ_PORT_MASK(C, PORTC_BIT6);

  fnDebugDec(irPort, 0);

  //Enable the Clock to the FTM0 Module

  SIM_SCGC6 |= SIM_SCGC6_FTM0;

  FTM0_SC |= FTM_SC_PS_1; // clock prescaler / 1

  //turn off FTM write protection;

  FTM0_MODE |= FTM_MODE_WPDIS;

  FTM0_MODE |= FTM_MODE_FTMEN;

  FTM0_SC = 0x0;

  FTM0_SC = 0; //Make sure its Off!

  FTM0_CNT = 0; //Reset counter, make sure we are starting at 0

  FTM0_MOD = (FTM_CSC_ELSA | FTM_CSC_ELSB);  //Set the overflow rate

  //FTM0_MOD = IRQ_RISING_EDGE;

  FTM0_SC |= FTM_SC_TOIE; //Enable the interrupt mask.

  FTM0_SC |= FTM_SC_CLKS_SYS; //Select the System Clock

  fnDebugMsg("Timer is running, with value: ");

  //fnDebugDec(FTM0_CNT, 0);

  fnDebugDec(FTM0_MOD, 0);

}

I dosen´t seems to work, i just geth the value 12 the hole time. Someone now whats maybe is wrong ?

27 Replies

72 Views
Futte
Contributor II

I think i have found what there is wrong. If i make this statement in isr:

FTM0_CNT = 0;

FTM0_C0SC &= ~FTM_CSC_CHF;

check = FTM_SC_TOF;

fnDebugDec(check, 0);

if( FTM0_SC |= FTM_SC_TOF)

{

  fnDebugMsg("Wrong");

}

else

{

  print = FTM0_C0V;

  fnDebugDec(print,0);

}

i am getting in to the wrong value when i push the button, so i think i need to clear the tof flag in some way

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Futte
Contributor II

Finally i goth the frequenzy, one off the thinks wash i needed to change the delay in the for loop to 8800 :smileyhappy:

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Futte
Contributor II

Ok

Its very short time

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Futte
Contributor II

I change so i now have FTM1_MODE |= FTM_MODE_FTMEN;

but nothing happens

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SergeMaslenniko
Contributor II

you need to configure FTM1_MOD with max value of the counter.

if 4096 is max value of your counter  FTM1_MOD = 4095

and FTM1_MODE you can configure in accordance with your task.

at least you did something like that: FTM1_MODE |= FTM_MODE_FTMEN;

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Futte
Contributor II

Hi

I have now try to change my code to:

FTM1.JPG

Its not make any sence to me any more

i have try to test the example FlexTimer_NVIC_IRQ and tryet to follow that example in som parts but i cant geth it

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Futte
Contributor II
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