Driving a raw LCD from MSP430

lcdlowpower.c

// 2010 Kenneth Finnegan
// http://kennethfinnegan.blogspot.com/
// Ultra-low power LCD counter experiment

#include "msp430G2231.h"

// Which digit is being displayed
volatile unsigned char mode;
// refresh periods spent in current mode
volatile unsigned char modecnt;

// bitmaps for the 7 segment digits 0-9
const unsigned char digits[] = { 0x7B, 0x18, 0x6D, 0x3D, 0x1E, 0x37, 0x77, 0x19, 0x7F, 0x1F};

// FUNCTIONS
void pause (int c);

void main(void) {
	WDTCTL = WDTPW + WDTHOLD;	// Stop Watchdog Timer

	BCSCTL2 = 0xF8; // MCLK:LFXT1CLK/8 SMCLK:LFXT1CLK
	
	
	P1DIR = 0xFF;
	P1OUT = 0x00;
	
	CCTL0 = CCIE;
	CCR0 = 0;
	TACCR0 = 0x3FF; // Period of 1023 + 1 cnts, which is 32Hz
	TACTL = 0x0211; // Timer_A: SMCLK, UP MODE, TAIE
	
	// Sleep forever...
	_BIS_SR(LPM1_bits + GIE);
}

#pragma vector=TIMERA0_VECTOR
__interrupt void Timer_A (void) {
	// Increment refresh count
	modecnt = (modecnt+1) % 32;
	// Change displayed digit every second
	if (modecnt == 0) {
		mode = (mode + 1) % 10;
		P1OUT = digits[mode];
	}
	
	// Reverse all pins to alternately bias the LCD
	P1OUT ^= 0xFF;
			
}