[board/chronos/drivers]

* simple buzzer driver

chronos/Jamrules.chronos

@@ -7,6 +7,8 @@ BOARD = chronos ;
 CPU = cc430 ;
 MCU = cc430x6137 ;
 
+HDRS += [ FPath $(TOP) board chronos drivers include ] ;
+
 FLASHER ?= mspdebug ;
 FLASHFLAGS ?= rf2500 ;
 

chronos/drivers/Jamfile

@@ -1,4 +1,7 @@
 SubDir TOP board chronos drivers ;
 
+HDRS += $(TOP)/board/$(CPU)/drivers/include ;
+
 Module board_display : display.c display1.c ;
 Module board_cc110x : cc430-cc110x.c : cc110x_cc430 ;
+Module board_buzzer : buzzer.c : hwtimer ;

chronos/drivers/buzzer.c

@@ -0,0 +1,27 @@
+#include <stdint.h>
+#include <buzzer.h>
+#include <cc430x613x.h>
+
+void buzzer_beep(uint8_t pitch, uint16_t duration) {
+    // Reset TA1R, set up mode, TA1 runs from 32768Hz ACLK 
+    TA1CTL = TACLR | MC_1 | TASSEL__ACLK;
+
+    // Set PWM frequency 
+    TA1CCR0 = pitch;
+
+    // Enable IRQ, set output mode "toggle"
+    TA1CCTL0 = OUTMOD_4;
+
+    // Allow buzzer PWM output on P2.7
+    P2SEL |= BIT7;
+
+    hwtimer_wait(duration);
+
+    // Stop PWM timer 
+    TA1CTL &= ~(BIT4 | BIT5);
+
+    // Reset and disable buzzer PWM output
+    P2OUT &= ~BIT7;
+    P2SEL &= ~BIT7;
+    TA1CCTL0 &= ~CCIE; 
+}

chronos/drivers/include/buzzer.h

@@ -0,0 +1,6 @@
+#ifndef BUZZER_H
+#define BUZZER_H 
+
+void buzzer_beep(uint8_t pitch, uint16_t duration);
+
+#endif /* BUZZER_H */