Add VoltageCheck to shutdown on low power

Makefile

@@ -7,7 +7,7 @@ OBJS = main.o
 
 VPATH +=
 OBJS +=
-OBJS += basic/basic.o basic/reinvoke_isp.o basic/delayms.o
+OBJS += basic/basic.o basic/reinvoke_isp.o basic/delayms.o basic/voltage.o
 OBJS += eeprom/eeprom.o
 LIBS += core/libcore.a lcd/liblcd.a modules/libmodules.a
 

basic/basic.h

@@ -126,4 +126,7 @@ void EnterISP(void);
 // delayms.c
 void delayms(uint32_t ms);
 
+// voltage.c
+void VoltageCheck(void);
+
 #endif

basic/voltage.c

@@ -0,0 +1,20 @@
+#include <sysinit.h>
+
+#include "basic/basic.h"
+
+
+void VoltageCheck(void){
+	uint32_t results;
+
+	results = adcRead(1);
+	results *= 10560;
+	results /= 1024;
+
+	if( results < 3500 ){
+	    gpioSetValue (RB_PWR_GOOD, 0); 
+	    gpioSetValue (RB_LCD_BL, 0); 
+	    SCB_SCR |= SCB_SCR_SLEEPDEEP;
+	    PMU_PMUCTRL = PMU_PMUCTRL_DPDEN_DEEPPOWERDOWN;
+	    __asm volatile ("WFI");
+    };
+};