43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
|
|
#ifndef FREQ_COUNTER_H
|
|
#define FREQ_COUNTER_H
|
|
|
|
#ifndef IRAM_ATTR
|
|
#define IRAM_ATTR __attribute__((section(".iram.text")))
|
|
#endif
|
|
|
|
struct freq_counter {
|
|
bool input_initialized; /* false before first update call */
|
|
bool input_state; /* last update input state */
|
|
|
|
uint32_t counter; /* input state changes counter */
|
|
uint32_t samples; /* input samples counter */
|
|
uint32_t cycle_len; /* number of samples in one cycle */
|
|
|
|
bool new_measurement; /* set to true after updating measurement */
|
|
uint32_t measurement; /* number of state changes in last complete cycle */
|
|
};
|
|
|
|
/**
|
|
* @brief initialize frequency counter structure
|
|
*
|
|
* @param cycle_len number of samples in one measurement cycle
|
|
*/
|
|
void freq_counter_init ( struct freq_counter *f, uint32_t cycle_len );
|
|
void IRAM_ATTR freq_counter_update ( struct freq_counter *f, bool input );
|
|
|
|
|
|
/**
|
|
* @brief get new measurement from freq_counter
|
|
*
|
|
* this function should be called at least twice per cycle in order to avoid
|
|
* concurrent rw acces to measurement variable
|
|
* @param measurement is set to new measurement value if returned true
|
|
* @return true if new measurement is available
|
|
*/
|
|
bool freq_counter_get_measurement( struct freq_counter *f, uint32_t *measurement);
|
|
|
|
#endif /* end of include guard: FREQ_COUNTER_H */
|