Quickie "police light" demo

[GeekDoc 226]

I made the following up as an exercise/proof of concept and as the start of a project for my kids. They love their cars and Legos, and I thought they might like some police-style flashing lights. I got a lot of the info from TI's Low Power mode demo.

 

The one thing I couldn't include was putting the 430 in a low power mode between watchdog interrupts. I'll have to look into that a bit more.

 

This will be one portion, I want different flash modes, and other light sets (headlights, rear lights...), probably using other timers/counters, selectable by a button, as long as I have enough pins (this one just uses the built-in LEDs on the LaunchPad).

 

Critiques appreciated.

 

//************************************************************************
// MSP430G2211 "Police Light" Demo - WDT
//
// Description: This program uses the WDT to generate an interrupt every
// ~8ms.  A counter and if/else logic is used to determine which LED to 
// access, and whether to turn the LED on or off.  This should result in
// the typical double-flash on one side, then the other of emergency
// vehicles.
//
// Carlton Dodd - http://blog.DocsTech.net  
//
//************************************************************************

#include "msp430g2231.h"
unsigned int wdtCounter = 0;

void main(void)
{
//SETUP
		WDTCTL = WDT_MDLY_8; 	// Set Watchdog Timer interval to ~8ms
	IE1 |= WDTIE; 			// Enable WDT interrupt

		P1DIR |= BIT0 + BIT6;   // P1.0 and 1.6 to output
		P1OUT = 0;			// P1 all off
		__enable_interrupt();

}

// Watchdog Timer interrupt
#pragma vector=WDT_VECTOR
__interrupt void watchdog_timer(void)
{
       // multiplied all checks by 10 to get 80ms flashes/delays
if(wdtCounter < 40) // first half of cycle, use LED1
{
	if(wdtCounter % 20 == 0)
	{
		P1OUT = BIT0; 	// P1.0 on (yes, I meant to just use '=' to clear all others)
	}
	else if (wdtCounter % 10 == 0)
	{
		P1OUT = 0;		// Turn all of P1 output off
	}
}
else // second half of cycle, use LED2
{
	if(wdtCounter % 20 == 0)
	{
		P1OUT = BIT6; 	// P1.6 on (yes, I meant to just use '=')
	}
	else if (wdtCounter % 10 == 0)
	{
		P1OUT = 0;		// Turn all of P1 output off
	}
}

wdtCounter++;

if(wdtCounter > 80) //cycle is complete, start over
{
	wdtCounter = 0;
}

}

 

-Doc

[bluehash 1,581]

Just got my Launchpad today and this was the first project I tried. +1 for your demo. Keep going.

Will comment as I code.

[GeekDoc 226]

Just got my Launchpad today and this was the first project I tried.

 

I am honored, sir.