led.c

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/*
 * led.c
 *
 *  Date: 19/06/2014
 *  Author: Fernando Biazi Nascimento
 *  Copyright © 2014 Fernando Biazi Nascimento. All rights reserved.
 *
 *  License of use and copy on file license.txt
 *
 */

/*
 * ======== Standard MSP430 includes ========
 */
#include <msp430.h>

/*
 * ======== Includes ========
 */

#include "led.h"
#include "im.h"

/*
 * ======== Constants ========
 */

#define LED_REDCTRLMASK 0x0F

#define LED_GREENCTRLMASK 0xF0

/*
 * ======== Macros ========
 */

#define LED_REDGET P1OUT & BIT0

#define LED_REDSET P1OUT |= BIT0

#define LED_REDCLR P1OUT &= ~BIT0

#define LED_GREENGET P1OUT & BIT1

#define LED_GREENSET P1OUT |= BIT1

#define LED_GREENCLR P1OUT &= ~BIT1

/*
 * ======== Types ========
 */

typedef enum led_state {
  LED_S_IDLE, LED_S_RUNNING
} led_state;

/*
 * ======== Global Variables ========
 */

/*
 * ======== Local Variables ========
 */

UInt8 led_control;

UInt16 led_redCfg;

led_state led_currentState;

/*
 * ======== Local Functions ========
 */

/*
 * ================
 */

void led_init() {
  led_control = 0;
  led_redCfg = 0x1F40 | 0x0005; // 500ms delay, blink 5 times
  led_currentState = LED_S_IDLE;
}

UInt16 led_proccess() {
  UInt8 n; // number of times red led must blink
  switch (led_currentState) {
  case LED_S_IDLE:
    led_currentState = LED_S_RUNNING;
    return 10;
  case LED_S_RUNNING:
    n = led_redCfg & 0x000F;
    if (n == 0) { // Don't blink, just wait 200ms, because configuration may change.
      LED_REDCLR;
      return 200;
    } else if ((led_control & LED_REDCTRLMASK) < n) { // Must blink n times.
      if (LED_REDGET) { // Led is on, add one to count (control) and wait for next time.
        if (led_redCfg >> 4) // if led off delay is zero, just don't count
          led_control++;   // and the LED will blink indefinitely.
        LED_REDCLR;
        return 199;
      } else { // Led is off, turn it on and wait 5ms to turn off.
        LED_REDSET;
        return 1;
      }
    } else { // Have blinked n times, clear count (control) and wait the delay to blink again.
      led_control &= ~LED_REDCTRLMASK;
      return (led_redCfg >> 4);
    }
  default:
    led_currentState = LED_S_IDLE;
    return 1;
  }
}

void led_redConfigure(UInt8 n, UInt16 offDelay) {
  led_redCfg = (n & 0x0F) | ((offDelay & 0x0FFF) << 4);
}

void led_greenUp() {
  im_disable_interrupt();
  if ((led_control & LED_GREENCTRLMASK) != 0xF0)
    led_control += 0x10;
  LED_GREENSET;
  im_enable_interrupt();
}

void led_greenDown() {
  im_disable_interrupt();
  if ((led_control & LED_GREENCTRLMASK) != 0x00)
    led_control -= 0x10;
  if ((led_control & LED_GREENCTRLMASK) == 0x00)
    LED_GREENCLR;
  im_enable_interrupt();
}