Part Number:MSP430G2553
Tool/software: Code Composer Studio
I am a beginner in working with MSP430G2553, I have to generate a SPWM with a carrier frequency (triangular) of 2.5 kHz and modulating frequency of 50Hz (sine) with a modulation index of 0.9 I have attempted to do so by writing the following code in CCSV5 (given below) However it is not giving me the desired output. Can someone kindly help me out in figuring out the same.
#include <msp430g2553.h>
#define pwmPeriod 400 // carrier of 2.5kHz and reference of 50Hz. PWM period is 0.4 ms.
const unsigned int phalfcycle[25] = {764,787,809,830,871,887,900,911,921,927,930,930,927,921,911,900,887,871,830,809,787,764};
unsigned int pulsecounterA0 = 0;
unsigned int pulsecounterA1 = 0;
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
//Calibrate DCO for 1MHz operation
BCSCTL1 = CALBC1_1MHZ;
DCOCTL = CALDCO_1MHZ;
P1OUT &= 0x00; // Setting all pins as low
P2OUT &= 0x00;
P1DIR |= BIT2 + BIT6; // PWM Outputs
P2DIR |= BIT1 + BIT2;
P1SEL |= BIT2;
P2SEL |= BIT1;
TACCR0 = pwmPeriod - 1; // setting PWM period to 0.4 ms, 400-1 clock ticks of SMCLK
TA1CCR0 = pwmPeriod - 1;
TACCTL0 = CCIE; // Enable Timer A0 Interrupt for CCR0
TA1CCTL0 = CCIE;
TACCTL1 = OUTMOD_2; // RESET/SET for Timer A0 CCR1
TA1CCTL1 = OUTMOD_6;
TACTL = TASSEL_2 + MC_1 + TACLR; // Timer_A0 control register with SMCLK = 1 MHz, Upmode. Starting the timer
TA1CTL = TASSEL_2 + MC_1 + TACLR;
_BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interrupt
}
// Timer A0 interrupt service routine
// #pragma is a catch-all preprocessor directive that is used to extend the functionality of the compiler that is not already covered by predefined directives.
//In this code, the compiler (and the linker) is being told that we are going to create an ISR for TIMER0_A0_VECTOR.
#pragma vector=TIMER0_A0_VECTOR
__interrupt void Timer_A0 (void)
{
//TACCTL1 = OUTMOD_7;
if (pulsecounterA0 < 25)
{
TACCR1 = phalfcycle[pulsecounterA0];
pulsecounterA0 = pulsecounterA0 + 1;
}
else
{
P1SEL ^= (BIT2 + BIT6);
pulsecounterA0 = 0;
}
}
// Timer A1 interrupt service routine
// #pragma is a catch-all preprocessor directive that is used to extend the functionality of the compiler that is not already covered by predefined directives.
//In this code, the compiler (and the linker) is being told that we are going to create an ISR for TIMER1_A0_VECTOR.
#pragma vector=TIMER1_A0_VECTOR
__interrupt void Timer_A1 (void)
{
if (pulsecounterA1 < 25)
{
TA1CCR1 = phalfcycle[pulsecounterA1];
pulsecounterA1 = pulsecounterA1 + 1;
}
else
{
P2SEL ^= (BIT1 + BIT2);
pulsecounterA1 = 0;
}
}
