The next step is to insert two delays in order to slow down the LED flash rate.
A 16-bit unsigned integer can represent a value from 0 to 65535.
While this is sufficient for our simple delay, we will use a 32-bit unsigned integer in case we need a longer delay at some point in the future.
32-bit unsigned long integer is good to 4,294,967,295
a bit more than we will ever need!
Here is the code:
The duration of each delay statement is about 250ms, i.e. the LED is on for 250ms and off for 250ms. The total period is 500ms, i.e. the LED flashes at a rate of two times each second.
A 16-bit unsigned integer can represent a value from 0 to 65535.
While this is sufficient for our simple delay, we will use a 32-bit unsigned integer in case we need a longer delay at some point in the future.
32-bit unsigned long integer is good to 4,294,967,295
a bit more than we will ever need!
Here is the code:
Code:
// Getting Started Tutorial - LED Flash
// 2013.04.19 - MrChips
#include "io430.h"
void init(void)
{
P1OUT = 0;
P1DIR = 0xFF;
}
void delay(unsigned long d)
{
unsigned long i;
for (i = 0; i < d; i++);
}
void main( void )
{
// Stop watchdog timer to prevent time out reset
WDTCTL = WDTPW + WDTHOLD;
init();
while (1)
{
P1OUT_bit.P0 = 1;
delay(25000);
P1OUT_bit.P0 = 0;
delay(25000);
}
}
