pdm_definitions.h File Reference

#include <board/board.h>
#include <pbl/drivers/mic.h>
#include <pbl/kernel/mutex.h>
#include <pbl/util/circular_buffer.h>
#include <stdbool.h>
#include <stdint.h>

Data Structures
struct	MicDevice
	nRF5 PDM microphone device. More...

Macros
#define	PDM_BUFFER_SIZE_SAMPLES   (320)
	Samples per PDM DMA buffer.
#define	PDM_BUFFER_COUNT   (2)
	Number of PDM DMA buffers.
#define	PDM_GAIN_DEFAULT   (NRF_PDM_GAIN_DEFAULT)
	Default PDM gain.
#define	CIRCULAR_BUF_SIZE_MS   (320)
	Preferred length of the queue between DMA and the data handler, in milliseconds.
#define	CIRCULAR_BUF_SIZE_SAMPLES   ((MIC_SAMPLE_RATE * CIRCULAR_BUF_SIZE_MS) / 1000)
	Preferred queue length, in samples.
#define	CIRCULAR_BUF_SIZE_BYTES   (CIRCULAR_BUF_SIZE_SAMPLES * sizeof(int16_t))
	Preferred queue size, in bytes.
#define	CIRCULAR_BUF_MIN_SIZE_MS   (128)
	Minimum queue length, in milliseconds, accepted when the heap is too fragmented for the preferred one.
#define	CIRCULAR_BUF_MIN_SIZE_SAMPLES   ((MIC_SAMPLE_RATE * CIRCULAR_BUF_MIN_SIZE_MS) / 1000)
	Minimum queue length, in samples.
#define	CIRCULAR_BUF_MIN_SIZE_BYTES   (CIRCULAR_BUF_MIN_SIZE_SAMPLES * sizeof(int16_t))
	Minimum queue size, in bytes.
#define	CIRCULAR_BUF_STEP_MS   (32)
	Queue shrink per allocation retry, in milliseconds.
#define	CIRCULAR_BUF_STEP_SAMPLES   ((MIC_SAMPLE_RATE * CIRCULAR_BUF_STEP_MS) / 1000)
	Queue shrink per allocation retry, in samples.
#define	CIRCULAR_BUF_STEP_BYTES   (CIRCULAR_BUF_STEP_SAMPLES * sizeof(int16_t))
	Queue shrink per allocation retry, in bytes.