Initial commit

led2.c

@@ -0,0 +1,77 @@
+
+#include <msp430.h>
+
+/*
+ * P1 bit 0 = red led.
+ * P1 bit 6 = green led.
+ * P1 bit 3 = button.
+ */
+
+ #define N_STATES 4
+
+int state = 0;
+
+/*  G | R | state (dec)
+ *  0 | 0 | 0
+ *  0 | 1 | 1
+ *  1 | 0 | 2
+ *  1 | 1 | 3
+ */
+
+void update(void) {
+
+	static unsigned in_progress = 0;
+
+	if (in_progress)
+		return;
+	in_progress = 1;
+
+	state = (state + 1) % N_STATES;
+
+	/* first bit set, enable red */
+	if (state & BIT0)
+		P1OUT |= BIT0;
+	else
+		P1OUT &= ~BIT0;
+
+	/* second bit set, enable green */
+	if (state & BIT1)
+		P1OUT |= BIT6;
+	else
+		P1OUT &= ~BIT6;
+
+	in_progress = 0;
+}
+
+void delay(void) {
+
+	int i = 0x6fff;
+
+	while(i--)
+		nop();
+}
+
+int main(void) {
+
+	/* Init watchdog timer to off */
+	WDTCTL = WDTPW | WDTHOLD;
+
+	/* set all P1 direction to input. */
+	P1DIR = 0x0;
+
+	/* set direction to output on both leds */
+	P1DIR |= (BIT0 | BIT6);
+
+	P1OUT = 0x0;
+
+	for(;;) {
+		/*
+		 * P1.3 bit set -> button _not_ pressed.
+		 */
+		if (!(P1IN & BIT3))
+			update();
+
+		delay();
+	}
+	return 0;
+}