Sense.BP

uint8_t tile_sense_bp_find(tiles_pal_t *hal, uint8_t instance)

Check if a Sense.BP is present on the bus.

hal

Platform HAL handle.

instance

0 = default address (0x5D), 1 = alternate (0x5C).

Returns 1 if device ACKs and WHO_AM_I matches, 0 otherwise.

void tile_sense_bp_init(tiles_pal_t *hal, uint8_t instance, tile_t *tile, const sense_bp_cfg_t *cfg)

Probes the device, verifies WHO_AM_I, configures ODR/AVG/FS/LPF/BDU, disables AH/Qvar for lower power, and sets tile state to READY.

hal

Platform HAL handle.

instance

0 = default (0x5D), 1 = alternate (0x5C).

tile

Tile handle to initialise.

cfg

Configuration (NULL for defaults).

void tile_sense_bp_sleep(tile_t *tile)

Enter power-down mode (ODR = 0).

void tile_sense_bp_wake(tile_t *tile)

Resume from power-down using cached ODR/AVG settings.

void tile_sense_bp_reset(tile_t *tile)

All registers return to defaults. Call init() again after reset.

int32_t tile_sense_bp_get_pressure_raw(tile_t *tile)

Read the raw 24-bit pressure output (two's complement).

Returns Raw 24-bit signed value, sign-extended to int32_t.

int32_t tile_sense_bp_get_pressure_mhpa(tile_t *tile)

Returns pressure * 1000 in mhPa units. For example, 1013250 = 1013.250 hPa. Accounts for the current full-scale mode setting.

Returns Pressure in milli-hPa (mhPa).

int16_t tile_sense_bp_get_temp_raw(tile_t *tile)

Read the raw 16-bit temperature output (two's complement).

Returns Raw 16-bit signed value, sign-extended to int16_t.

int32_t tile_sense_bp_get_temp_cdeg(tile_t *tile)

Returns temperature * 100. For example, 2534 = 25.34 °C. Sensor sensitivity is 100 LSB/°C, so this is (raw * 100) / 100 = raw.

Returns Temperature in centi-°C.

void tile_sense_bp_oneshot(tile_t *tile)

ODR must be POWERDOWN. Sets the ONESHOT bit in CTRL_REG2. The bit self-clears when the measurement is complete.

uint8_t tile_sense_bp_get_status(tile_t *tile)

Read the STATUS register.

Returns Raw STATUS byte (use ILPS22QS_STATUS_* masks).

uint8_t tile_sense_bp_pressure_ready(tile_t *tile)

Check if new pressure data is available.

Returns 1 if P_DA is set, 0 otherwise.

uint8_t tile_sense_bp_temp_ready(tile_t *tile)

Check if new temperature data is available.

Returns 1 if T_DA is set, 0 otherwise.

uint8_t tile_sense_bp_is_boot_complete(tile_t *tile)

After VDD ramps, the ILPS22QS reloads its trim parameters from NVM. The BOOT_ON bit in INT_SOURCE reads 1 during this phase and 0 once the chip is ready to be configured. Reads of this getter are non-clearing (the BOOT_ON bit is preserved across the read; only the threshold/IA flags clear on read). Useful when interrogating the chip immediately after VDD comes up, or after software reset. A typical pattern: tile_sense_bp_reset(&baro); while (!tile_sense_bp_is_boot_complete(&baro)) core_delay_ms(1); // chip is now ready for re-configuration

Returns 1 if boot complete (BOOT_ON cleared), 0 if still booting.

int32_t tile_sense_bp_read_altitude_mm(tile_t *tile, uint32_t sea_level_pa)

Pure-integer linear approximation around the reference pressure: h_mm = 8430 * (P0_pa - P_pa) / 100 which corresponds to ~8.43 mm of altitude per pascal of pressure decrease — the standard-atmosphere lapse-rate slope near sea level. Accuracy regime: this is a first-order linearisation valid for roughly ±1500 m around the supplied reference (i.e. the kind of range you care about for indoor floor detection, ascent-rate estimation, or short-baseline relative-altitude tracking). Error grows with the cube of altitude — at ±3000 m the underlying exponential law diverges from the linear fit by tens of metres, and outside the ILPS22QS's pressure range (260–1260 hPa or 260–4060 hPa depending on FS mode) the result is meaningless. For absolute geodetic altitude over wide ranges, use a full barometric-formula library on a host with floats. The reference is supplied in pascals (not hPa) for the convenience of callers that already have a recent QNH/QFE figure handy. Pass `101325` for the ICAO standard sea level reference. the reference. Negative when the measured pressure exceeds the reference (deeper than the reference altitude).

sea_level_pa

[26000..406000] Pa Reference pressure (e.g. 101325).

Returns Altitude in millimetres above (positive) or below (negative)

uint8_t tile_sense_bp_wait_for_pressure_change(tile_t *tile, uint16_t threshold_hpa, uint32_t timeout_ms)

Captures the current pressure at call time, then polls at the chip's configured ODR cadence until either: - |pressure - baseline| >= threshold_hpa, or - timeout_ms elapses with no qualifying change. This is a blocking helper. The polling cadence is derived from the cached CTRL_REG1 ODR field — the function sleeps for one ODR period between samples (or 10 ms as a fallback if ODR is power-down or unrecognised). For one-shot users, configure a non-power-down ODR before calling. Useful for "tap-to-wake" altitude triggers, ascent/descent detection, or pressure-step-driven UI events — without committing to the full threshold-interrupt configuration in CTRL_REG3 / INTERRUPT_CFG.

threshold_hpa

[1..4060] hPa Absolute deviation that triggers return.

timeout_ms

[0..600000] ms Maximum wait.

Returns 1 if the threshold was crossed, 0 if the call timed out.

void tile_sense_bp_set_odr(tile_t *tile, sense_bp_odr_t odr)

SENSE_BP_ODR_POWERDOWN stops conversions (use oneshot() to take a reading), so Studio offers only the running rates. init() default: 25 Hz.

odr

Desired output data rate.

void tile_sense_bp_set_avg(tile_t *tile, sense_bp_avg_t avg)

Trades noise for current: at 25 Hz with the LPF at ODR/4 the pressure noise falls from 2.87 Pa RMS (4 samples) to 0.44 Pa (512), while the supply current rises from 23 µA to 784 µA (datasheet Tables 22, 24). init() default: 4 samples.

avg

Desired averaging.

void tile_sense_bp_set_fullscale(tile_t *tile, sense_bp_fs_t fs)

Mode 1 (up to 1260 hPa) has twice the resolution and about half the noise of mode 2 (up to 4060 hPa). init() default: mode 1.

fs

Full-scale selection.

void tile_sense_bp_set_lpf(tile_t *tile, uint8_t enable, sense_bp_lpf_bw_t bw)

The filter on the pressure output (CTRL_REG2 EN_LPFP / LFPF_CFG) cuts the noise further at no current cost: at 25 Hz with 4-sample averaging, 4.26 Pa RMS unfiltered, 2.87 at ODR/4, 2.20 at ODR/9 (datasheet Table 24). init() default: on, at ODR/4.

enable

[0..1] 1 = enable, 0 = disable.

bw

Bandwidth selection (only used if enable = 1).

void tile_sense_bp_set_threshold_hpa(tile_t *tile, uint16_t ths_hpa)

The threshold is applied to the differential pressure (P_DIFF_IN), so it needs AUTOREFP or AUTOZERO. Enable PHE/PLE bits in INTERRUPT_CFG to generate interrupts. THS_P is 15 bits (hPa × 16 in mode 1, × 8 in mode 2); values past 2047 hPa (mode 1) / 4095 hPa (mode 2) saturate.

ths_hpa

[0..2047] hPa Threshold (unsigned, applied symmetrically).

void tile_sense_bp_set_interrupt_cfg(tile_t *tile, uint8_t cfg)

Configure the interrupt source register.

cfg

[0..255] Raw INTERRUPT_CFG byte (use ILPS22QS_INTCFG_* masks).

uint8_t tile_sense_bp_get_int_source(tile_t *tile)

Read the interrupt source register (clears latched flags).

Returns Raw INT_SOURCE byte (use ILPS22QS_INT_SRC_* masks).

void tile_sense_bp_set_autozero(tile_t *tile)

Captures current pressure as REF_P. Output registers then show the difference from reference. Reset with reset_autozero().

void tile_sense_bp_reset_autozero(tile_t *tile)

Reset autozero mode to normal operation.

void tile_sense_bp_set_autorefp(tile_t *tile)

Captures current pressure as REF_P for interrupt threshold comparison. Output registers are not affected. Reset with reset_autorefp().

void tile_sense_bp_reset_autorefp(tile_t *tile)

Reset autorefp mode to normal operation.

void tile_sense_bp_set_pressure_offset(tile_t *tile, int16_t offset)

The offset is in raw LSB units (signed 16-bit) and is subtracted from the measured pressure before output.

offset

[-32768..32767] Raw offset value (two's complement).

int16_t tile_sense_bp_get_ref_pressure(tile_t *tile)

Read the reference pressure registers (REF_P).

Returns 16-bit signed reference pressure value.

void tile_sense_bp_set_fifo_mode(tile_t *tile, sense_bp_fifo_mode_t mode)

Configure the FIFO mode.

mode

FIFO mode selection.

void tile_sense_bp_set_fifo_watermark(tile_t *tile, uint8_t watermark)

Set the FIFO watermark threshold (0–127).

watermark

[0..127] Threshold level.

uint8_t tile_sense_bp_get_fifo_level(tile_t *tile)

Read the number of unread FIFO samples.

Returns Number of unread samples (0–128).

uint8_t tile_sense_bp_get_fifo_status(tile_t *tile)

Read FIFO status flags.

Returns Raw FIFO_STATUS2 byte (use ILPS22QS_FIFO_* masks).

int32_t tile_sense_bp_read_fifo_raw(tile_t *tile)

Read one raw 24-bit pressure sample from the FIFO.

Returns Raw 24-bit signed pressure value, sign-extended to int32_t.

uint8_t tile_sense_bp_read_fifo_batch(tile_t *tile, int32_t *buf, uint8_t count)

24-bit signed values (sign-extended to int32_t). many samples and returns the actual count.

buf

Caller-allocated buffer the driver fills with raw

count

Capacity of `buf` — the driver fills up to this

Returns Number of samples actually read.