LESENSE - Low Energy Sensor Interface#

sl_hal_lesense_clock_prescale_t#

sl_hal_lesense_clock_prescale_t

Clock divisors for controlling the prescaling factor of the period counter.

Note

• These enumeration values are used for different clock division related configuration parameters.

sl_hal_lesense_scan_mode_t#

sl_hal_lesense_scan_mode_t

Scan modes.

sl_hal_lesense_prs_source_t#

sl_hal_lesense_prs_source_t

PRS sources.

Note

• These enumeration values are being used for different PRS related. configuration parameters.

sl_hal_lesense_scan_config_t#

sl_hal_lesense_scan_config_t

Scan configuration.

sl_hal_lesense_control_dac_data_t#

sl_hal_lesense_control_dac_data_t

DAC CHx data control configuration.

Note

• This value could be used for both DAC Ch0 and Ch1.

sl_hal_lesense_control_acmp_t#

sl_hal_lesense_control_acmp_t

ACMPx control configuration.

Note

• This value could be used for both ACMP0 and ACMP1.

sl_hal_lesense_channel_sample_t#

sl_hal_lesense_channel_sample_t

Compare source selection for sensor sampling.

sl_hal_lesense_channel_interrupt_t#

sl_hal_lesense_channel_interrupt_t

Interrupt generation setup for CHx interrupt flag.

sl_hal_lesense_pin_excitation_phase_t#

sl_hal_lesense_pin_excitation_phase_t

Channel pin mode for the excitation phase of the scan sequence.

sl_hal_lesense_pin_idle_mode_t#

sl_hal_lesense_pin_idle_mode_t

Channel pin mode for the idle phase of scan sequence.

Note

• This value could be used for all channels.

sl_hal_lesense_excitation_clock_t#

sl_hal_lesense_excitation_clock_t

Clock used for excitation and sample delay timing.

sl_hal_lesense_compare_counter_t#

sl_hal_lesense_compare_counter_t

Compare modes for counter comparison.

sl_hal_lesense_store_sample_data_t#

sl_hal_lesense_store_sample_data_t

Mode of Storing of Sensor Sample in Result Buffer.

sl_hal_lesense_sensor_evaluation_t#

sl_hal_lesense_sensor_evaluation_t

Sensor evaluation modes.

sl_hal_lesense_transition_action_t#

sl_hal_lesense_transition_action_t

Transition action modes.

sl_hal_lesense_init#

void sl_hal_lesense_init (const sl_hal_lesense_init_t * init)

Initialize the LESENSE module.

This function configures the main parameters of the LESENSE interface. See the initialization parameter type definition (sl_hal_lesense_init_t) for more details.

Note

• Function sl_hal_lesense_init() is designed to initialize LESENSE once in an operation cycle. Be aware of the effects of reconfiguration if using this function from multiple sources in your code. This function has not been designed to be re-entrant. Notice that GPIO pins used by the LESENSE module must be properly configured by the user explicitly for the LESENSE to work as intended. (When configuring pins, one should remember to consider the sequence of configuration to avoid unintended pulses/glitches on output pins.) LESENSE needs to be disabled before configuring any register.

sl_hal_lesense_set_scan_frequency#

uint32_t sl_hal_lesense_set_scan_frequency (uint32_t reference_frequency, uint32_t scan_frequency)

Set the scan frequency for periodic scanning.

This function only applies to LESENSE if a period counter is used as a trigger for scan start. The calculation is based on the following formula: Fscan = LFACLKles / ((1+PCTOP)*2^PCPRESC)

Note

• Note that the calculation does not necessarily result in the requested scan frequency due to integer division. Check the return value for the resulted scan frequency. LESENSE needs to be disabled before configuring any register.

Returns

• Frequency in Hz calculated and set by this function. Users can use this to compare the requested and set values.

sl_hal_lesense_set_clock_division#

void sl_hal_lesense_set_clock_division (sl_hal_lesense_excitation_clock_t clock, sl_hal_lesense_clock_prescale_t clock_divisor)

Set the clock division for LESENSE timers.

Use this function to configure the clock division for the LESENSE timers used for excitation timing. The division setting is global but the clock source can be selected for each channel using sl_hal_lesense_channel_config() function. See documentation for more details.

Note

• If AUXHFRCO is used for excitation timing, LFACLK can't exceed 500 kHz. LFACLK can't exceed 50 kHz if the ACMP threshold level (ACMPTHRES) is not equal for all channels. LESENSE needs to be disabled before configuring any register.

• SL_HAL_LESENSE_EXCITATION_TIMING_AUXHFRCO - set AUXHFRCO clock divisor for HF timer.

• SL_HAL_LESENSE_EXCITATION_TIMING_LFACLK - set LFACLKles clock divisor for LF timer.

sl_hal_lesense_channel_config_all#

void sl_hal_lesense_channel_config_all (const sl_hal_lesense_channel_all_t * config_all_channel)

Configure all (16) LESENSE sensor channels.

This function configures all sensor channels of the LESENSE interface. See the configuration parameter type definition (sl_hal_lesense_channel_all_t) for more details.

Note

• Channels can be configured individually using sl_hal_lesense_channel_config() function. Notice that pins used by the LESENSE module must be properly configured by the user explicitly for LESENSE to work as intended. (When configuring pins, consider the sequence of the configuration to avoid unintended pulses/glitches on output pins.)

sl_hal_lesense_channel_config#

void sl_hal_lesense_channel_config (const sl_hal_lesense_channel_descriptor_t * config_channel, uint32_t channel_index)

Configure a single LESENSE sensor channel.

This function configures a single sensor channel of the LESENSE interface. See the configuration parameter type definition (sl_hal_lesense_channel_descriptor_t) for more details.

Note

• This function has been designed to minimize the effects of sensor channel reconfiguration while LESENSE is in operation. However, be aware of these effects and the right timing to call this function. Parameter pin_alternate_excite must be true in the channel configuration to use alternate excitation pins. LESENSE needs to be disabled before configuring any register.

sl_hal_lesense_channel_enable#

void sl_hal_lesense_channel_enable (uint8_t channel_index, bool enable_scan_channel, bool enable_pin)

Enable/disable LESENSE scan channel and the pin assigned to it.

Use this function to enable/disable a selected LESENSE scan channel and the pin assigned to it.

Note

• Users can enable/disable scan channels and the channel pin with the sl_hal_lesense_channel_config() function, but only with a significant overhead. This simple function controls these parameters after the channel has been configured.

sl_hal_lesense_channel_enable_mask#

void sl_hal_lesense_channel_enable_mask (uint16_t channel_mask, uint16_t pin_mask)

Enable/disable LESENSE scan channel and the pin assigned to it.

Use this function to enable/disable LESENSE scan channels and the pins assigned to them using a mask.

Note

• Users can enable/disable scan channels and channel pins by using the sl_hal_lesense_channel_config_all() function, but only with a significant overhead. This function controls these parameters after the channel has been configured.

sl_hal_lesense_channel_set_threshold#

void sl_hal_lesense_channel_set_threshold (uint8_t channel_index, uint16_t acmp_threshold, uint16_t count_threshold)

Set LESENSE channel threshold parameters.

Use this function to set threshold parameters on a selected LESENSE channel.

Note

• Users can configure the channel threshold parameters with the sl_hal_lesense_channel_config() function, but only with a significant overhead. This function serves controls these parameters after the channel has been configured. LESENSE needs to be disabled before configuring INTERACT register and needs to be enabled when configuring EVALTHRES register.

• If per_control.dac_channel0_data is set to SL_HAL_LESENSE_DAC_CH_DATA, acmp_threshold defines the 12-bit DAC data in the corresponding data register of the DAC interface (DACn_CH0DATA and DACn_CH1DATA). In this case, the valid range is 0-4095 (12 bits).

sl_hal_lesense_channel_config_sliding_window#

void sl_hal_lesense_channel_config_sliding_window (uint8_t channel_index, uint32_t window_size, uint32_t init_value)

Configure a Sliding Window evaluation mode for a specific channel.

This function will configure the evaluation mode, the initial sensor measurement (COMPTHRES), and the window size. For other channel-related configuration, see the sl_hal_lesense_channel_config() function.

Note

• LESENSE needs to be disabled before configuring EVALCFG register and needs to be enabled when configuring EVALTHRES register.

Warnings

• Note that the step size and window size configuration are global to all LESENSE channels and use the same register field in the hardware. This means that any window_size configuration passed to this function will apply for all channels and override all other step_size/window_size configurations.

sl_hal_lesense_channel_config_step_detection#

void sl_hal_lesense_channel_config_step_detection (uint8_t channel_index, uint32_t step_size, uint32_t init_value)

Configure the step detection evaluation mode for a specific channel.

This function will configure the evaluation mode, the initial sensor measurement (COMPTHRES) and the window size. For other channel-related configuration, see the sl_hal_lesense_channel_config() function.

Warnings

• Note that the step size and window size configuration are global to all LESENSE channels and use the same register field in the hardware. This means that any step_size configuration passed to this function will apply for all channels and override all other step_size/window_size configurations. LESENSE needs to be disabled before configuring EVALCFG register and needs to be enabled when configuring EVALTHRES register.

sl_hal_lesense_config_alternate_excitation#

void sl_hal_lesense_config_alternate_excitation (const sl_hal_lesense_channel_alternate_excitation_t * config_alternate_excitation)

Configure the LESENSE alternate excitation modes.

This function enable/disable the alternate excitation channels of the LESENSE interface. See the configuration parameter type definition (sl_hal_lesense_channel_alternate_excitation_t) for more details.

Note

• The config_alternate_excitation parameter must be true in the channel configuration structure (sl_hal_lesense_channel_descriptor_t) to use alternate excitation pins on the channel.

sl_hal_lesense_decoder_config_all_arcs#

void sl_hal_lesense_decoder_config_all_arcs (const sl_hal_lesense_all_transition_arcs_t * config_all_arcs)

Configure all LESENSE transition ARCs.

This function configures all the transition ARC of the LESENSE interface. See the configuration parameter type definition (sl_hal_lesense_all_transition_arcs_t) for more details.

sl_hal_lesense_enable#

void sl_hal_lesense_enable (void )

Enable the LESENSE module.

sl_hal_lesense_wait_sync#

void sl_hal_lesense_wait_sync (void )

Wait for ongoing sync of register(s) to complete before writing to any other register.

sl_hal_lesense_wait_ready#

void sl_hal_lesense_wait_ready (void )

Wait for disabling to finish.

sl_hal_lesense_disable#

void sl_hal_lesense_disable (void )

Disable the LESENSE module.

sl_hal_lesense_decoder_start#

void sl_hal_lesense_decoder_start (void )

Start the LESENSE decoder.

Note

• This function will wait for any pending previous write operation to the CMD register to complete before accessing the CMD register. It will also wait for the write operation to the CMD register to complete before returning. Each write operation to the CMD register may take up to 3 LF clock cycles, so expect some delay. The user may implement a separate function to write multiple command bits in the CMD register in one single operation to optimize an application.

sl_hal_lesense_decoder_stop#

void sl_hal_lesense_decoder_stop (void )

Stop LESENSE decoder.

Disables LESENSE decoder by setting the command to LESENSE_DECCTRL register.

sl_hal_lesense_set_scan_mode#

void sl_hal_lesense_set_scan_mode (sl_hal_lesense_scan_mode_t scan_mode)

Set scan mode of the LESENSE channels.

This function configures how the scan start is triggered. It can be used for re-configuring the scan mode while running the application but it is also used by sl_hal_lesense_init() for initialization.

Note

• Users can configure the scan mode by sl_hal_lesense_init() function, but only with a significant overhead. This simple function serves the purpose of controlling this parameter after the channel has been configured. Be aware of the effects of the non-atomic Read-Modify-Write cycle. LESENSE needs to be disabled before configuring any register.

• SL_HAL_LESENSE_SCAN_START_PERIODIC - A new scan is started each time the period counter overflows.

• SL_HAL_LESENSE_SCAN_START_ONESHOT - A single scan is performed when sl_hal_lesense_start_scan() function is called.

• SL_HAL_LESENSE_SCAN_START_PRS - A new scan is triggered by pulse on the PRS channel.

sl_hal_lesense_start_scan#

void sl_hal_lesense_start_scan (void )

Start scanning sensors.

Note

• This function will wait for any pending previous write operation to the CMD register to complete before accessing the CMD register. It will also wait for the write operation to the CMD register to complete before returning. Each write operation to the CMD register may take up to 3 LF clock cycles, so expect some delay. The user may implement a separate function to write multiple command bits in the CMD register in one single operation to optimize an application.

sl_hal_lesense_stop_scan#

void sl_hal_lesense_stop_scan (void )

Stop scanning sensors.

Note

• This function will wait for any pending previous write operation to the CMD register to complete before accessing the CMD register. It will also wait for the write operation to the CMD register to complete before returning. Each write operation to the CMD register may take up to 3 LF clock cycles, so the user should expect some delay. The user may implement a separate function to write multiple command bits in the CMD register in one single operation in order to optimize an application. If issued during a scan, the command takes effect after scan completion.

sl_hal_lesense_set_start_delay#

void sl_hal_lesense_set_start_delay (uint8_t start_delay)

Set the start delay of the sensor interaction on each channel.

This function sets the start delay of the sensor interaction on each channel. It can be used for adjusting the start delay while running the application but it is also used by sl_hal_lesense_init() for initialization.

Note

• Users can configure the start delay by sl_hal_lesense_init() function, but only with a significant overhead. This simple function serves the purpose of controlling this parameter after the channel has been configured. Be aware of the effects of the non-atomic Read-Modify-Write cycle. LESENSE needs to be disabled before configuring any register.

sl_hal_lesense_set_window_size#

void sl_hal_lesense_set_window_size (uint32_t window_size)

Set the window size for all LESENSE channels.

The window size is used by all channels that are configured as SL_HAL_LESENSE_EVALUATION_MODE_SLIDING_WINDOW.

Note

• LESENSE needs to be disabled before configuring EVALCTRL register.

Warnings

• The window size configuration is using the same register field as the step detection size. As a result, the window size configuration will have an effect on channels configured with the SL_HAL_LESENSE_EVALUATION_MODE_STEP_DETECTION evaluation mode as well.

sl_hal_lesense_set_step_size#

void sl_hal_lesense_set_step_size (uint32_t step_size)

Set the step size for all LESENSE channels.

The step size is configured using the same register field as used to configure window size. Therefore, calling this function will overwrite any previously configured window size as done by the sl_hal_lesense_set_window_size() function.

sl_hal_lesense_decoder_config_arc#

void sl_hal_lesense_decoder_config_arc (const sl_hal_lesense_transition_arc_t * config_arc, uint32_t arc_index)

Configure a single LESENSE transition ARC.

This function configures a transition ARC of the LESENSE interface. See the configuration parameter type definition sl_hal_lesense_transition_arc_t for more details.

Note

• LESENSE needs to be disabled before configuring STx_ARC register.

sl_hal_lesense_decoder_enable_prs_output#

void sl_hal_lesense_decoder_enable_prs_output (uint32_t decoder_mask, uint32_t decoder_compare)

Enable the PRS output from the LESENSE decoder.

sl_hal_lesense_decoder_disable_prs_output#

void sl_hal_lesense_decoder_disable_prs_output (void )

Disable the PRS output from the LESENSE decoder.

sl_hal_lesense_get_status#

uint32_t sl_hal_lesense_get_status (void )

Get the current status of LESENSE.

Returns

• Returns the value of the LESENSE_STATUS register that contains the OR combination of the following status bits for EFR series 2:

  • LESENSE_STATUS_RESFIFOV - Result Fifo valid. Set when data is available in result Fifo. Cleared when Fifo is empty.

  • LESENSE_STATUS_RESFIFOFULL - Result Fifo full. Set when result Fifo is full.

  • LESENSE_STATUS_RUNNING - LESENSE is active.

  • LESENSE_STATUS_SCANACTIVE - LESENSE is currently interfacing sensors.

  • LESENSE_STATUS_FLUSHING - Fifo flushing

  • LESENSE_STATUS_READBUSY - Fifo Read busy

sl_hal_lesense_channel_set_timing#

void sl_hal_lesense_channel_set_timing (uint8_t channel_index, uint8_t excitation_time, uint8_t sample_delay, uint16_t measure_delay)

Set LESENSE channel timing parameters.

Use this function to set timing parameters on a selected LESENSE channel.

Note

• Users can configure the channel timing parameters with the sl_hal_lesense_channel_config() function, but only with a significant overhead. This function controls these parameters after the channel has been configured. LESENSE needs to be disabled before configuring any register.

sl_hal_lesense_wait_status#

void sl_hal_lesense_wait_status (uint32_t flag)

Wait until status of LESENSE is equal to what was requested.

Polls LESENSE_STATUS register and waits until requested combination of flags are set.

sl_hal_lesense_channel_get_active#

uint32_t sl_hal_lesense_channel_get_active (void )

Get the currently active channel index.

Returns

• Returns the value of the LESENSE_CHINDEX register that contains the index of currently active channel (0-15).

sl_hal_lesense_get_scan_result#

uint32_t sl_hal_lesense_get_scan_result (void )

Get the latest scan comparison result (1 bit / channel).

Returns

• Returns the value of the LESENSE_SCANRES register that contains the comparison result of last scan on all channels. Bit x is set if a comparison triggered on channel x, which means that LESENSE counter met the comparison criteria set in LESENSE_CHx_EVAL by COMPMODE and CNTTHRES.

sl_hal_lesense_get_scan_result_data#

uint32_t sl_hal_lesense_get_scan_result_data (void )

Get the oldest unread data from the result buffer.

Note

• Make sure that the STORERES bit is set in LESENSE_CHx_EVAL, or the STRSCANRES bit is set in LESENSE_CTRL; otherwise, returns the undefined value.

Returns

• Returns the value of LESENSE_RESDATA register that contains the oldest unread counter result from result buffer.

sl_hal_lesense_clear_result_buffer#

void sl_hal_lesense_clear_result_buffer (void )

Clear the result buffer.

Note

• This function will wait for any pending previous write operation to the CMD register to complete before accessing the CMD register. It will also wait for the write operation to the CMD register to complete before returning. Each write operation to the CMD register may take up to 3 LF clock cycles, so expect some delay. The user may implement a separate function to write multiple command bits in the CMD register in one single operation to optimize an application.

sl_hal_lesense_decoder_get_state#

uint32_t sl_hal_lesense_decoder_get_state (void )

Get the current state of the LESENSE decoder.

Returns

• This function returns the value of the LESENSE_DECSTATE register that represents the current state of the LESENSE decoder.

sl_hal_lesense_get_sensor_state#

uint32_t sl_hal_lesense_get_sensor_state (void )

Get the current state of the LESENSE sensor.

Returns

• Returns the value of LESENSE_SENSORSTATE register that represents the current state of the LESENSE sensor.

sl_hal_lesense_reset#

void sl_hal_lesense_reset (void )

Reset the LESENSE module.

Use this function to reset LESENSE registers.

Note

• Resetting LESENSE registers is required in each reset or power-on cycle to configure the default values of the RAM mapped LESENSE registers. sl_hal_lesense_reset() can be called on initialization by setting the req_reset parameter to true in sl_hal_lesense_init(). Starting from Series 2 Config 3 (xG23 and higher), this function leaves LESENSE in the disabled state.

sl_hal_lesense_clear_interrupts#

void sl_hal_lesense_clear_interrupts (uint32_t flags)

Clear one or more pending LESENSE interrupts.

sl_hal_lesense_enable_interrupts#

void sl_hal_lesense_enable_interrupts (uint32_t flags)

Enable one or more LESENSE interrupts.

sl_hal_lesense_disable_interrupts#

void sl_hal_lesense_disable_interrupts (uint32_t flags)

Disable one or more LESENSE interrupts.

sl_hal_lesense_set_interrupts#

void sl_hal_lesense_set_interrupts (uint32_t flags)

Set one or more pending LESENSE interrupts from SW.

sl_hal_lesense_get_pending_interrupts#

uint32_t sl_hal_lesense_get_pending_interrupts (void )

Get pending LESENSE interrupt flags.

Note

• Event bits are not cleared by the use of this function.

Returns

• Pending LESENSE interrupt sources. The OR combination of valid interrupt flags of the LESENSE module (LESENSE_IF_nnn).

sl_hal_lesense_get_enabled_pending_interrupts#

uint32_t sl_hal_lesense_get_enabled_pending_interrupts (void )

Get enabled and pending LESENSE interrupt flags.

Useful for handling more interrupt sources in the same interrupt handler.

Note

• Event bits are not cleared by the use of this function.

Returns

• Pending and enabled LESENSE interrupt sources. Return value is the bitwise AND combination of

  • the OR combination of enabled interrupt sources in LESENSE_IEN_nnn register (LESENSE_IEN_nnn).

  • the OR combination of valid interrupt flags of LESENSE module (LESENSE_IF_nnn).