Diff: WakeUp.h

Revision:

0:fc439458a359

Child:

1:92f4c2b52771

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WakeUp.h	Sat Nov 23 11:35:14 2013 +0000
@@ -0,0 +1,71 @@
+#include "mbed.h"
+
+/**
+* Class to make use of the LPC81x's low power wake-up timer.
+*
+* One of the methods of waking up from deepsleep/powerdown is using the wake-up timer.
+* This is an ultra low-power timer that can run from an always-on 10kHz clock source.
+* So while normal timers are shut-down, this one still runs, consuming only roughly 1uA.
+* If the timer does not need to run everything is shut down again by the library.
+*
+* This class can also be used as general purpose interrupt timer, although just using 
+* the default Timer library is probably a better idea for that.
+*
+* Example program: http://mbed.org/users/Sissors/code/LPC812_Sleep_HelloWorld/
+*/
+class WakeUp
+{
+public:
+    /**
+    * Set the timeout
+    *
+    * @param s - required time in seconds
+    */
+    static void set(uint32_t s) {
+        set_ms(1000 * s);
+    }
+    
+    /**
+    * Set the timeout
+    *
+    * @param ms - required time in milliseconds
+    */
+    static void set_ms(uint32_t ms);
+    
+    /**
+    * Attach a function to be called after timeout
+    *
+    * This is optional, if you just want to wake up you 
+    * do not need to attach a function.
+    *
+    * Also supports normal way to attach member functions
+    * (not documented for simplicity)
+    *
+    * @param *function - function to call
+    */
+    static void attach(void (*function)(void)) {
+        callback.attach(function);
+    }
+
+    template<typename T>
+    static void attach(T *object, void (T::*member)(void)) {
+        callback.attach(object, member);
+    }
+    
+    /**
+    * Calibrate the timer
+    *
+    * The 10kHz timer has a very bad accuracy: +/- 45%.
+    * This function calibrates it for 100ms against the main clock.
+    * So you get almost that accuracy by calling this function. 
+    *
+    * Warning: Blocks for 100ms!
+    */
+    static void calibrate(void);
+
+
+private:
+    static FunctionPointer callback;
+    static void irq_handler(void);
+    static float cycles_per_ms;
+};
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