Texas Instruments MSP430

130
In the main loop, we are using the Launchpad’s user button to alter TA0CCR0’s value and hence PWM
frequency or period. There are ten different time periods to select. The main code also displays
captured waveform time period vs expected time period on a LCD.
if((P1IN & BIT3) == 0)
{
P1OUT |= BIT0;
while((P1IN & BIT3) == 0);
i++;
if(i > 9)
{
i = 0;
}
P1OUT &= ~BIT0;
}
switch(i)
{
case 1:
{
TA0CCR0 = 9999;
LCD_goto(0, 1);
LCD_putstr("Period/ms: 20");
break;
}
case 2:
{
TA0CCR0 = 4999;
LCD_goto(0, 1);
LCD_putstr("Period/ms: 10");
break;
}
case 3:
{
TA0CCR0 = 1999;
LCD_goto(0, 1);
LCD_putstr("Period/ms: 4");
break;
}
case 4:
{
TA0CCR0 = 999;
LCD_goto(0, 1);
LCD_putstr("Period/ms: 2");
break;
}
case 5:
{
TA0CCR0 = 166;
LCD_goto(0, 1);
LCD_putstr("Period/us: 334");
break;
}
case 6:
{
TA0CCR0 = 1230;
LCD_goto(0, 1);