[board/chronos]

* introduced battery driver

chronos/drivers/Jamfile

@@ -5,5 +5,6 @@ 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 ;
+Module battery : battery.c : adc hwtimer ;
 
 Module display_putchar : display_putchar.c : board_display ;

chronos/drivers/battery.c

@@ -0,0 +1,13 @@
+#include <stdint.h>
+#include <cc430x613x.h>
+#include <cc430-adc.h>
+
+uint16_t battery_get_voltate(void) {
+    uint16_t voltage;
+    voltage = adc12_single_conversion(REFVSEL_1, ADC12SHT0_10, ADC12INCH_11);
+
+    /* Ideally we have A11=0->AVCC=0V ... A11=4095(2^12-1)->AVCC=4V
+     * --> (A11/4095)*4V=AVCC --> AVCC=(A11*4)/4095 */
+    voltage = (voltage * 2 * 2 * 1000) / 4095;  
+    return voltage;
+}

chronos/drivers/include/battery.h

@@ -0,0 +1,6 @@
+#ifndef BATTERY_H
+#define BATTERY_H 
+
+uint16_t battery_get_voltate(void);
+
+#endif /* BATTERY_H */