PDM driver

nRF5 SDK v12.1.0
Modules | Data Structures | Macros | Typedefs | Functions

nRF52 only: Pulse density modulation (PDM) interface driver. More...

Modules

PDM peripheral driver configuration

Data Structures

struct nrf_drv_pdm_config_t
PDM interface driver configuration structure. More...

Macros

#define NRF_PDM_MAX_BUFFER_SIZE 32768
#define NRF_DRV_PDM_DEFAULT_CONFIG (PIN_CLK, PIN_DIN, BUFF_A, BUFF_B, BUFF_LEN)
Macro for setting nrf_drv_pdm_config_t to default settings in single ended mode. More...

Typedefs

typedef void(* nrf_drv_pdm_event_handler_t )(uint32_t *buffer, uint16_t length)
Handler for PDM interface ready events. More...

Functions

ret_code_t nrf_drv_pdm_init ( nrf_drv_pdm_config_t const *p_config, nrf_drv_pdm_event_handler_t event_handler)
Function for initializing the PDM interface. More...
void nrf_drv_pdm_uninit (void)
Function for uninitializing the PDM interface. More...
__STATIC_INLINE uint32_t nrf_drv_pdm_task_address_get ( nrf_pdm_task_t task)
Function for getting the address of a PDM interface task. More...
__STATIC_INLINE bool nrf_drv_pdm_enable_check ()
Function for getting the state of the PDM interface. More...
ret_code_t nrf_drv_pdm_start (void)
Function for starting PDM sampling. More...
ret_code_t nrf_drv_pdm_stop (void)
Function for stopping PDM sampling. More...

Detailed Description

nRF52 only: Pulse density modulation (PDM) interface driver.

Macro Definition Documentation

#define NRF_DRV_PDM_DEFAULT_CONFIG ( PIN_CLK,
PIN_DIN,
BUFF_A,
BUFF_B,
BUFF_LEN
)
Value:
{ \
.mode = ( nrf_pdm_mode_t ) PDM_CONFIG_MODE , \
.edge = ( nrf_pdm_edge_t ) PDM_CONFIG_EDGE , \
.pin_clk = PIN_CLK, \
.pin_din = PIN_DIN, \
.clock_freq = ( nrf_pdm_freq_t ) PDM_CONFIG_CLOCK_FREQ , \
.gain_l = NRF_PDM_GAIN_DEFAULT, \
.gain_r = NRF_PDM_GAIN_DEFAULT, \
.interrupt_priority = PDM_CONFIG_IRQ_PRIORITY , \
.buffer_length = BUFF_LEN, \
.buffer_a = BUFF_A, \
.buffer_b = BUFF_B \
}

Macro for setting nrf_drv_pdm_config_t to default settings in single ended mode.

Parameters
PIN_CLK CLK output pin.
PIN_DIN DIN input pin.
BUFF_A Sample buffer A (filled first).
BUFF_B Sample buffer B (filled after buffer A).
BUFF_LEN Length of a single buffer (in 16-bit words).

Typedef Documentation

typedef void(* nrf_drv_pdm_event_handler_t)(uint32_t *buffer, uint16_t length)

Handler for PDM interface ready events.

This event handler is called when a buffer is full and ready to be processed.

Parameters
[in] p_buffer Sample buffer pointer.
[in] length Buffer length in 16-bit words.

Function Documentation

__STATIC_INLINE bool nrf_drv_pdm_enable_check ( )

Function for getting the state of the PDM interface.

Return values
TRUE If the PDM interface is enabled.
FALSE If the PDM interface is disabled.
ret_code_t nrf_drv_pdm_init ( nrf_drv_pdm_config_t const * p_config ,
nrf_drv_pdm_event_handler_t event_handler
)

Function for initializing the PDM interface.

Parameters
[in] p_config Pointer to a configuration structure. If NULL, the default one is used.
[in] event_handler Event handler provided by the user.
Return values
NRF_SUCCESS If initialization was successful.
NRF_ERROR_INVALID_STATE If the driver is already initialized.
NRF_ERROR_INVALID_PARAM If invalid parameters were specified.
ret_code_t nrf_drv_pdm_start ( void )

Function for starting PDM sampling.

Return values
NRF_SUCCESS If sampling was started successfully or was already in progress.
NRF_ERROR_BUSY If a previous start/stop operation is in progress.
ret_code_t nrf_drv_pdm_stop ( void )

Function for stopping PDM sampling.

When this function is called, the PDM interface is stopped after finishing the current frame. The event handler function might be called once more after calling this function.

Return values
NRF_SUCCESS If sampling was stopped successfully or was already stopped before.
NRF_ERROR_BUSY If a previous start/stop operation is in progress.
__STATIC_INLINE uint32_t nrf_drv_pdm_task_address_get ( nrf_pdm_task_t task )

Function for getting the address of a PDM interface task.

Parameters
[in] task Task.
Returns
Task address.
void nrf_drv_pdm_uninit ( void )

Function for uninitializing the PDM interface.

This function stops PDM sampling, if it is in progress.