ASYNC two software timers on different hardware timers?

jasaleja

Hello everyone,

I wrote a little code for my MSP432 to use two software timers on two separate hardware timers.

The first hardware timer runs on SMCLK 3Mhz/64 and counts to 46875 before the interrupt. That is 1 second. And on that timer runs a software timer that counts 2 seconds, and then it triggers a red LED.

The second hardware timer runs on SMCLK 3Mhz and counts to 3000 before the interrupt. That is 1 m second. And on that timer runs a software timer that counts 500 m seconds, and then it triggers a blue LED.

So after i run the program the blue and red LED should both turn off after 4 seconds. But after a few minutes the 2 LEDS get async and i dont know why.

Does someone have an explanation?

I think its because no 2 hardware timers can be in sync.

over 9 years ago

0 jasaleja over 9 years ago

Intellectual 985 points

I forgot to add the code

Fullscreen 7801.main.c Download

//*****************************************************************************
//
// MSP432 main.c template - Empty main
//
//****************************************************************************

/* Ukljucenja */
#include "msp.h"
#include "driverlib.h"

/* Definicije */
#define ZASTAVA_GORE		1
#define ZASTAVA_DOLE		0

#define DEAKTIVIRAN			0
#define TAJMER1s			1
#define	TAJMER1ms			2

#define MAX_BROJ_TAMJMERA	8
#define TIMER_PERIOD_1s		46875				// 3MHz/64
#define TIMER_PERIOD_1ms	3000				// 3MHz/1000

/* Definicije tipova */
typedef struct softTajmer_s{
	uint8_t		aktiviran;
	uint8_t		zastava;
	uint16_t	brojac;
	uint16_t	broj;
} softTajmer;

/* Prototipovi */
void AktivirajSoftTajmer(uint8_t redniBroj, uint16_t broj, uint8_t tajmer);
void DektivirajSoftTajmer(uint8_t redniBroj);
void ResetujSoftTajmer(uint8_t redniBroj);


const Timer_A_UpModeConfig upConfig1s =
{
        TIMER_A_CLOCKSOURCE_SMCLK,				// SMCLK Clock Source
        TIMER_A_CLOCKSOURCE_DIVIDER_64,			// SMCLK/1 = 3MHz
        TIMER_PERIOD_1s,
        TIMER_A_TAIE_INTERRUPT_DISABLE,			// Disable Timer interrupt
        TIMER_A_CCIE_CCR0_INTERRUPT_ENABLE,		// Enable CCR0 interrupt
        TIMER_A_DO_CLEAR						// Clear value
};

const Timer_A_UpModeConfig upConfig1ms =
{
        TIMER_A_CLOCKSOURCE_SMCLK,				// SMCLK Clock Source
        TIMER_A_CLOCKSOURCE_DIVIDER_1,			// SMCLK/1 = 3MHz
        TIMER_PERIOD_1ms,
        TIMER_A_TAIE_INTERRUPT_DISABLE,			// Disable Timer interrupt
        TIMER_A_CCIE_CCR0_INTERRUPT_ENABLE,		// Enable CCR0 interrupt
        TIMER_A_DO_CLEAR						// Clear value
};

softTajmer	tajmeri[MAX_BROJ_TAMJMERA];
uint8_t		brojPrekida;

#define BROJAC1 1
#define BROJAC2	500

uint16_t	brojac1;
uint16_t	brojac2;

void main(void)
{
	/* Stop WDT  */
	MAP_WDT_A_holdTimer();

	/* Konfigurisi P1.0 kao izlaz */
	MAP_GPIO_setAsOutputPin(GPIO_PORT_P1, GPIO_PIN0);
	MAP_GPIO_setOutputLowOnPin(GPIO_PORT_P1, GPIO_PIN0);
	/* Konfigurisi P2.2 kao izlaz */
	MAP_GPIO_setAsOutputPin(GPIO_PORT_P2, GPIO_PIN2);
	MAP_GPIO_setOutputLowOnPin(GPIO_PORT_P2, GPIO_PIN2);

	MAP_GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P4,
	            GPIO_PIN3, GPIO_PRIMARY_MODULE_FUNCTION);

	/* Podesi tajmere da rade u UpMode */
	MAP_Timer_A_configureUpMode(TIMER_A0_BASE, &upConfig1s);
	MAP_Timer_A_configureUpMode(TIMER_A1_BASE, &upConfig1ms);

	/* Odobri prekide */
	MAP_Interrupt_enableSleepOnIsrExit();
	MAP_Interrupt_enableInterrupt(INT_TA0_0);
	MAP_Interrupt_enableInterrupt(INT_TA1_0);

	/* Aktiviraj odredjene sofverske tajmere */
	AktivirajSoftTajmer(0, 2, TAJMER1s);			// Radice po tajmeru za 1s
	AktivirajSoftTajmer(1, 500, TAJMER1ms);			// Radice po tajmeru za 1ms

	/* Pokreni tajmer */
	MAP_Timer_A_startCounter(TIMER_A0_BASE, TIMER_A_UP_MODE);
	MAP_Timer_A_startCounter(TIMER_A1_BASE, TIMER_A_UP_MODE);

	brojac1 = BROJAC1;
	brojac2 = BROJAC2;

	/* Odobri GLAVNI prekid */
	MAP_Interrupt_enableMaster();

	/* Spavaj kada se ne koristi */
	while (1)
	{
		MAP_PCM_gotoLPM0();
	}
}

void AktivirajSoftTajmer(uint8_t redniBroj, uint16_t broj, uint8_t tajmer)
{
	tajmeri[redniBroj].aktiviran = tajmer;
	tajmeri[redniBroj].zastava = ZASTAVA_DOLE;
	tajmeri[redniBroj].brojac = broj;
	tajmeri[redniBroj].broj = broj;
}

void DektivirajSoftTajmer(uint8_t redniBroj)
{
	tajmeri[redniBroj].aktiviran = DEAKTIVIRAN;
}

void ResetujSoftTajmer(uint8_t redniBroj)
{
	tajmeri[redniBroj].brojac = tajmeri[redniBroj].broj;
}

void TA0_0_1s_RukovaocPrekida(void)
{
	/*int i;
	MAP_Timer_A_clearCaptureCompareInterrupt(TIMER_A0_BASE,
					TIMER_A_CAPTURECOMPARE_REGISTER_0);
	for(i=0; i<MAX_BROJ_TAMJMERA; i++)
	{
		if(tajmeri[i].aktiviran == TAJMER1s)
		{
			tajmeri[i].brojac--;
			if(tajmeri[i].brojac == 0)
			{
				tajmeri[i].zastava = ZASTAVA_GORE;
				brojPrekida++;
				ResetujSoftTajmer(i);
				MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P1, GPIO_PIN0);
				//izadji iz LP
			}
		}
	}*/
	MAP_Timer_A_clearCaptureCompareInterrupt(TIMER_A0_BASE,
						TIMER_A_CAPTURECOMPARE_REGISTER_0);
	brojac1--;
	if(brojac1 == 0)
	{
		MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P1, GPIO_PIN0);
		brojac1 = BROJAC1;
	}
}

extern void TA1_0_1ms_RukovaocPrekida(void)
{
	/*int i;
	MAP_Timer_A_clearCaptureCompareInterrupt(TIMER_A1_BASE,
					TIMER_A_CAPTURECOMPARE_REGISTER_0);
	for(i=0; i<MAX_BROJ_TAMJMERA; i++)
	{
		if(tajmeri[i].aktiviran == TAJMER1ms)
		{
			tajmeri[i].brojac--;
			if(tajmeri[i].brojac == 0)
			{
				tajmeri[i].zastava = ZASTAVA_GORE;
				brojPrekida++;
				ResetujSoftTajmer(i);
				MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P2, GPIO_PIN2);
				//izadji iz LP
			}
		}
	}*/
	MAP_Timer_A_clearCaptureCompareInterrupt(TIMER_A1_BASE,
						TIMER_A_CAPTURECOMPARE_REGISTER_0);
	brojac2--;
	if(brojac2 == 0)
	{
		MAP_GPIO_toggleOutputOnPin(GPIO_PORT_P2, GPIO_PIN2);
		brojac2 = BROJAC2;
	}
}

0 Bruce McKenney over 9 years ago in reply to jasaleja

Guru 100125 points

You need to subtract 1 from TIMER_PERIOD_[1s,1ms] so the timer counts properly.

As it is, each is off by 1 tick, but since the "1ms" timer cycles more often, it drifts faster than the "1s" timer.

0 jasaleja over 9 years ago in reply to Bruce McKenney

Intellectual 985 points

I thought that was the error but it cant be. It first decrements, and then I check if it equals zero. That is the software timer, aha. You mean for the hardware timers... I will check it now. Thanks

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ASYNC two software timers on different hardware timers?