41 lines
		
	
	
	
		
			943 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			41 lines
		
	
	
	
		
			943 B
		
	
	
	
		
			C
		
	
	
	
	
	
| #include "ch.h"
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| 
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| #include "timer.h"
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| 
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| static systime_t last_systime = 0;
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| static systime_t overflow = 0;
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| static uint32_t current_time_ms = 0;
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| 
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| void timer_init(void) {
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|   timer_clear();
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| }
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| 
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| void timer_clear(void) {
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|   last_systime = chVTGetSystemTime();
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|   overflow = 0;
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|   current_time_ms = 0;
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| }
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| 
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| uint16_t timer_read(void) {
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|   return (uint16_t)timer_read32();
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| }
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| 
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| uint32_t timer_read32(void) {
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|   // Note: We assume that the timer update is called at least once betweeen every wrap around of the system time
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|   systime_t current_systime = chVTGetSystemTime();
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|   systime_t elapsed = current_systime - last_systime + overflow;
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|   uint32_t elapsed_ms = ST2MS(elapsed);
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|   current_time_ms += elapsed_ms;
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|   overflow = elapsed - MS2ST(elapsed_ms);
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|   last_systime = current_systime;
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| 
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|   return current_time_ms;
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| }
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| 
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| uint16_t timer_elapsed(uint16_t last) {
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|   return timer_read() - last;
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| }
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| 
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| uint32_t timer_elapsed32(uint32_t last) {
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|   return timer_read32() - last;
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| }
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