delay using timer

Official Hardware Mega Due
1

I want to use timers to measure time between two time instances. I tried these two approaches but none of them seem to work. output is always printed as 0.

// lets use timer number 6 (ch1, timer 2), address values are from the datasheet
// addresses are for capture mode.
unsigned int volatile * const TC_Control = (unsigned int *) 0x40084080;
unsigned int volatile * const TC_Mode = (unsigned int *) 0x40084084;
unsigned int volatile * const TC_Value = (unsigned int *) 0x40084090;

static void stop_timer()
{
	Serial.println("stopping timer");
	// control register - setting this to one will enable timer, set to 2 to disable timer
	*TC_Control = TC_CCR_CLKDIS;
}
static void start_timer()
{
	Serial.println("starting timer");

	// this is used to set the prescalar, set it to 2 to use TIMER_CLOCK3 (MCK/32)
	*TC_Mode = 2;
	// control register - setting this to one will enable timer, set to 2 to disable timer
	*TC_Control = TC_CCR_CLKEN | TC_CCR_SWTRG;
}



void setup()
{
	unsigned int t1, t2;
	Serial.begin(115200);
	start_timer();

	t1 = *TC_Value;
	Serial.print("time 1 is ");
	Serial.println(t1);

       // some more code comes here.

	t2 = *TC_Value;
	Serial.print("time 2 is ");
	Serial.println(t2);
	Serial.print("time taken by setup: ");
	Serial.println(t2-t1);
	Serial.println("exiting setup");
}

I also tried the arduino calls. that also printed zero.

void setup()
{
	unsigned int t1, t2;
	Serial.begin(115200);
	start_timer();

	t1 = TC_ReadCV(TC1, 2);
	Serial.print("time 1 is ");
	Serial.println(t1);
    // some code here..

	t2 = TC_ReadCV(TC1, 2);
	Serial.print("time 2 is ");
	Serial.println(t2);
	Serial.print("time taken by setup: ");
	Serial.println(t2-t1);

	Serial.println("exiting setup");
}


static void stop_timer()
{
	Serial.println("stopping timer");

	TC_Stop(TC1, 2);
}
static void start_timer()
{
	Serial.println("starting timer");

	TC_Configure(TC1, 2, TC_CMR_WAVE | TC_CMR_TCCLKS_TIMER_CLOCK3);
	TC_Start(TC1, 2);
}
2

got it... i need to start the clock before doing the TC_Configure, like this -

pmc_enable_periph_clk(ID_TC5);

3

Hi, I'am trying to get time between two events but I also get only zeros. My code looks like this:

#include "avr/io.h"
#include "Arduino.h"
#include "../../Atmel/Atmel Toolchain/AVR8 GCC/Native/3.4.1056/avr8-gnu-toolchain/avr/include/avr/iomxx0_1.h"
#include "wiring.h"
#include "C:\Program Files (x86)\Arduino\hardware\arduino\sam\system\libsam\include\tc.h"
#include "C:\Program Files (x86)\Arduino\hardware\arduino\sam\system\libsam\include\pmc.h"
#include "time.h"
#include "sys\types.h"

//ports:
const int zero_signal = A0;
const int return_signal = A1;
const int sync_signal = 24;
const int clock_signal = 22;

//variables:
boolean clk, sync;
unsigned long int zero_value = 0, return_value = 0;
double zero_rise[3], return_rise[3], tim;
int i = 0, j = 0;

void setup()
{
	//put your setup code here, to run once:
	Serial.begin(115200);
	pinMode(zero_signal, INPUT);
	pinMode(return_signal, INPUT);
	pinMode(sync_signal, INPUT);
	pinMode(clock_signal, INPUT);

	//MCK = 84MHz
	//timer tuning:
	//long dummy=REG_TC0_SR0; //vital - reading this clears some flag, otherwise you get infinite interrupts
	//NVIC_EnableIRQ(TC0_IRQn); //enable TC0 interrupts
	//REG_PIOA_PDR = 1<<25; //disable PIO, enable peripheral
	//REG_PIOA_ABSR= 1<<25; //select peripheral A

	analogReadResolution(12);
}

void loop()
{
	//put your main code here, to run repeatedly:
	clk = digitalRead(clock_signal);
	sync = digitalRead(sync_signal);

	//if (clk) == 1 & sync == 0)
	//{
	zero_signal_1:
	zero_rise[i] = analogRead(zero_signal);
	if (i == 1)
	{
		zero_rise[2] = ((zero_rise[1] - zero_rise[0]) / 4095);
		if (((atan(zero_rise[2]))*180)/PI >= 2)
		{
			//start timer
			Serial.println("Start timer");
			Serial.flush();
			pmc_enable_periph_clk(ID_TC1);
			TC_Configure(TC1, 2, TC_CMR_WAVE | TC_CMR_TCCLKS_TIMER_CLOCK3);
			TC_Start(TC1, 2);
		}
		else
		{
			i = 0;
			goto zero_signal_1;
		}
	}
	else
	{
		i++;
		goto zero_signal_1;
	}
	
	return_signal_1:
	return_rise[j] = analogRead(return_signal);
	if (j == 1)
	{
		return_rise[2] = ((return_rise[1] - return_rise[0]) / 4095);
		if (((atan(return_rise[2]))*180)/PI >= 2)
		{
			//stop counter
			tim = TC_ReadCV(TC1, 2);
			TC_Stop(TC1, 2);
			Serial.println(tim);
			Serial.println("Stop timer");
			Serial.flush();
		}
		else
		{
			j = 0;
			goto return_signal_1;
		}
	}
	else
	{
		j++;
		goto return_signal_1;
	}
	//}
}

Could you help my to configure clock correctly?