Lh2#

group bsp_lh2: Control the LH2 sensor.

Author: Filip Maksimovic filip.maksimovic@inria.fr
Author: Said Alvarado-Marin said-alexander.alvarado-marin@inria.fr
Author: Alexandre Abadie alexandre.abadie@inria.fr
Copyright: Inria, 2022-present

Defines

LH2_BASESTATION_COUNT#: Number of supported concurrent basestations.

LH2_POLYNOMIAL_COUNT#: Number of supported LFSR polynomials, two per basestation.

LH2_SWEEP_COUNT#: Number of laser sweeps per basestations rotation.

Enums

enum db_lh2_data_ready_state_t#

LH2 data ready buffer state.

Values:

enumerator DB_LH2_NO_NEW_DATA#: The data occupying this spot of the buffer has already been sent.

enumerator DB_LH2_RAW_DATA_AVAILABLE#: The data occupying this spot of the buffer is new and ready to send.

enumerator DB_LH2_PROCESSED_DATA_AVAILABLE#: The data occupying this spot of the buffer is new and ready to send.

Functions

void db_lh2_init(db_lh2_t *lh2, const gpio_t *gpio_d, const gpio_t *gpio_e)#

Initialize LH2.

Parameters:

lh2 – [in] pointer to the lh2 instance
gpio_d – [in] pointer to gpio data
gpio_e – [in] pointer to gpio event

void db_lh2_process_raw_data(db_lh2_t *lh2)#

Process raw data coming from the lighthouse, but skip the polynomial count calculation.

Parameters:

lh2 – [in] pointer to the lh2 instance

void db_lh2_process_location(db_lh2_t *lh2)#

Compute the location based on raw data coming from the lighthouse.

Parameters:

lh2 – [in] pointer to the lh2 instance

void db_lh2_start(void)#: Start the LH2 frame acquisition.

void db_lh2_stop(void)#: Stop the LH2 frame acquisition.

void db_lh2_reset(db_lh2_t *lh2)#

Reset the lh2 internal state so new location computation can be made.

Parameters:

lh2 – [in] pointer to the lh2 instance

struct db_lh2_raw_data_t#

LH2 raw data.

Public Members

uint64_t bits_sweep#: bits sweep is the result of the demodulation, sweep_N indicates which SPI transfer those bits are associated with

uint8_t selected_polynomial#: selected poly is the polyomial # (between 0 and 31) that the demodulation code thinks the demodulated bits are a part of, initialize to error state

int8_t bit_offset#: bit_offset indicates an offset between the start of the packet, as indicated by envelope dropping, and the 17-bit sequence that is verified to be in a known LFSR sequence

struct db_lh2_location_t#

LH2 raw data location.

Public Members

uint8_t selected_polynomial#: selected poly is the polyomial # (between 0 and 31) that the demodulation code thinks the demodulated bits are a part of, initialize to error state

uint32_t lfsr_location#: LFSR location is the position in a given polynomial’s LFSR that the decoded data is, initialize to error state.

struct db_lh2_t#

LH2 instance (one row per laser sweep, and one column per basestation)

Public Members

db_lh2_raw_data_t raw_data[LH2_SWEEP_COUNT][LH2_BASESTATION_COUNT]#: raw data decoded from the lighthouse

db_lh2_location_t locations[LH2_SWEEP_COUNT][LH2_BASESTATION_COUNT]#: buffer holding the computed locations

uint32_t timestamps[LH2_SWEEP_COUNT][LH2_BASESTATION_COUNT]#: timestamp of when the raw data was received

db_lh2_data_ready_state_t data_ready[LH2_SWEEP_COUNT][LH2_BASESTATION_COUNT]#: Is the data in the buffer ready to send over radio, or has it already been sent ?

uint8_t *spi_ring_buffer_count_ptr#: pointer to the SPI rung buffer packet count, so the user application can read how many spi captures are waiting to be processed.