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pimoroni-pico/drivers/vl53l1x/vl53l1x.cpp

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// Most of the functionality of this library is based on the VL53L1X API
// provided by ST (STSW-IMG007), and some of the explanatory comments are quoted
// or paraphrased from the API source code, API user manual (UM2356), and
// VL53L1X datasheet. Therefore, the license terms for the API source code
// (BSD 3-clause "New" or "Revised" License) also apply to this derivative work.
// Based on the code in https://github.com/pololu/vl53l1x-arduino
// Modified by https://github.com/simon3270/driver-vl53l1x
#include "vl53l1x.hpp"
// Constructors ////////////////////////////////////////////////////////////////
namespace pimoroni {
// Public Methods //////////////////////////////////////////////////////////////
// Initialize sensor using settings taken mostly from VL53L1_DataInit() and
// VL53L1_StaticInit().
// We are running a breakout, so will definitely configure the sensor for 2V8 mode
uint16_t VL53L1X::getid() {
return readReg16Bit(IDENTIFICATION__MODEL_ID);
}
uint16_t VL53L1X::getosc() {
return readReg16Bit(OSC_MEASURED__FAST_OSC__FREQUENCY);
}
void VL53L1X::setosc(uint16_t value) {
writeReg16Bit(OSC_MEASURED__FAST_OSC__FREQUENCY, value);
}
bool VL53L1X::init(bool io_2v8)
{
// Set some defaults
setTimeout(0);
did_timeout = false;
calibrated = true;
saved_vhv_init = 0;
saved_vhv_timeout = 0;
// distance_mode = 1;
last_status = 0;
// check model ID and module type registers (values specified in datasheet)
if (readReg16Bit(IDENTIFICATION__MODEL_ID) != 0xEACC) { return false; }
// VL53L1_software_reset() begin
writeReg(SOFT_RESET, 0x00);
sleep_us(100);
writeReg(SOFT_RESET, 0x01);
// give it some time to boot; otherwise the sensor NACKs during the readReg()
// call below and the Arduino 101 doesn't seem to handle that well
sleep_ms(1000);
// VL53L1_poll_for_boot_completion() begin
startTimeout();
// check last_status in case we still get a NACK to try to deal with it correctly
while ((readReg(FIRMWARE__SYSTEM_STATUS) & 0x01) == 0 || last_status != 0)
{
if (checkTimeoutExpired())
{
did_timeout = true;
return false;
}
}
// VL53L1_poll_for_boot_completion() end
// VL53L1_software_reset() end
// VL53L1_DataInit() begin
// sensor uses 1V8 mode for I/O by default; switch to 2V8 mode if necessary
if (io_2v8)
{
writeReg(PAD_I2C_HV__EXTSUP_CONFIG,
readReg(PAD_I2C_HV__EXTSUP_CONFIG) | 0x01);
}
// store oscillator info for later use
fast_osc_frequency = readReg16Bit(OSC_MEASURED__FAST_OSC__FREQUENCY);
osc_calibrate_val = readReg16Bit(RESULT__OSC_CALIBRATE_VAL);
// VL53L1_DataInit() end
// VL53L1_StaticInit() begin
// Note that the API does not actually apply the configuration settings below
// when VL53L1_StaticInit() is called: it keeps a copy of the sensor's
// register contents in memory and doesn't actually write them until a
// measurement is started. Writing the configuration here means we don't have
// to keep it all in memory and avoids a lot of redundant writes later.
// the API sets the preset mode to LOWPOWER_AUTONOMOUS here:
// VL53L1_set_preset_mode() begin
// VL53L1_preset_mode_standard_ranging() begin
// values labeled "tuning parm default" are from vl53l1_tuning_parm_defaults.h
// (API uses these in VL53L1_init_tuning_parm_storage_struct())
// static config
// API resets PAD_I2C_HV__EXTSUP_CONFIG here, but maybe we don't want to do
// that? (seems like it would disable 2V8 mode)
writeReg16Bit(DSS_CONFIG__TARGET_TOTAL_RATE_MCPS, TargetRate); // should already be this value after reset
writeReg(GPIO__TIO_HV_STATUS, 0x02);
writeReg(SIGMA_ESTIMATOR__EFFECTIVE_PULSE_WIDTH_NS, 8); // tuning parm default
writeReg(SIGMA_ESTIMATOR__EFFECTIVE_AMBIENT_WIDTH_NS, 16); // tuning parm default
writeReg(ALGO__CROSSTALK_COMPENSATION_VALID_HEIGHT_MM, 0x01);
writeReg(ALGO__RANGE_IGNORE_VALID_HEIGHT_MM, 0xFF);
writeReg(ALGO__RANGE_MIN_CLIP, 0); // tuning parm default
writeReg(ALGO__CONSISTENCY_CHECK__TOLERANCE, 2); // tuning parm default
// general config
writeReg16Bit(SYSTEM__THRESH_RATE_HIGH, 0x0000);
writeReg16Bit(SYSTEM__THRESH_RATE_LOW, 0x0000);
writeReg(DSS_CONFIG__APERTURE_ATTENUATION, 0x38);
// timing config
// most of these settings will be determined later by distance and timing
// budget configuration
writeReg16Bit(RANGE_CONFIG__SIGMA_THRESH, 360); // tuning parm default
writeReg16Bit(RANGE_CONFIG__MIN_COUNT_RATE_RTN_LIMIT_MCPS, 192); // tuning parm default
// dynamic config
writeReg(SYSTEM__GROUPED_PARAMETER_HOLD_0, 0x01);
writeReg(SYSTEM__GROUPED_PARAMETER_HOLD_1, 0x01);
writeReg(SD_CONFIG__QUANTIFIER, 2); // tuning parm default
// VL53L1_preset_mode_standard_ranging() end
// from VL53L1_preset_mode_timed_ranging_*
// GPH is 0 after reset, but writing GPH0 and GPH1 above seem to set GPH to 1,
// and things don't seem to work if we don't set GPH back to 0 (which the API
// does here).
writeReg(SYSTEM__GROUPED_PARAMETER_HOLD, 0x00);
writeReg(SYSTEM__SEED_CONFIG, 1); // tuning parm default
// from VL53L1_config_low_power_auto_mode
writeReg(SYSTEM__SEQUENCE_CONFIG, 0x8B); // VHV, PHASECAL, DSS1, RANGE
writeReg16Bit(DSS_CONFIG__MANUAL_EFFECTIVE_SPADS_SELECT, 200 << 8);
writeReg(DSS_CONFIG__ROI_MODE_CONTROL, 2); // REQUESTED_EFFFECTIVE_SPADS
// VL53L1_set_preset_mode() end
// default to long range, 50 ms timing budget
// note that this is different than what the API defaults to
setDistanceMode(Long);
setMeasurementTimingBudget(50000);
// VL53L1_StaticInit() end
// the API triggers this change in VL53L1_init_and_start_range() once a
// measurement is started; assumes MM1 and MM2 are disabled
writeReg16Bit(ALGO__PART_TO_PART_RANGE_OFFSET_MM,
readReg16Bit(MM_CONFIG__OUTER_OFFSET_MM) * 4);
return true;
}
// Write an 8-bit register
void VL53L1X::writeReg(uint16_t reg, uint8_t value)
{
uint8_t buffer[3] = {(reg >> 8) & 0xFF, reg & 0xFF, value};
i2c->write_blocking(address, buffer, 3, false);
}
// Write a 16-bit register
void VL53L1X::writeReg16Bit(uint16_t reg, uint16_t value)
{
uint8_t buffer[4] = {(reg >> 8) & 0xFF, reg & 0xFF, (value >> 8) & 0xFF, value & 0xFF};
i2c->write_blocking(address, buffer, 4, false);
}
// Write a 32-bit register
void VL53L1X::writeReg32Bit(uint16_t reg, uint32_t value)
{
uint8_t buffer[6] = {(reg >> 8) & 0xFF, reg & 0xFF,
(value >> 24) & 0xFF, (value >> 16) & 0xFF, (value >> 8) & 0xFF, value & 0xFF};
i2c->write_blocking(address, buffer, 6, false);
}
// Read an 8-bit register
uint8_t VL53L1X::readReg(regAddr reg)
{
uint8_t regbuf[2] = {((uint8_t)reg >> 8) & 0xFF, (uint8_t)reg & 0xFF};
uint8_t buffer[1];
uint8_t value;
i2c->write_blocking(address, regbuf, 2, true);
i2c->read_blocking(address, buffer, 1, false);
value = buffer[0];
return value;
}
// Read a 16-bit register
uint16_t VL53L1X::readReg16Bit(uint16_t reg)
{
uint8_t regbuf[2] = {(reg >> 8) & 0xFF, reg & 0xFF};
uint8_t buffer[2];
uint16_t value;
reg= (reg << 8) + (reg >> 8);
i2c->write_blocking(address, regbuf, 2, true);
i2c->read_blocking(address, buffer, 2, false);
value= (buffer[0] << 8) + buffer[1];
return value;
}
// Read a 32-bit register
uint32_t VL53L1X::readReg32Bit(uint16_t reg)
{
uint8_t regbuf[2] = {(reg >> 8) & 0xFF, reg & 0xFF};
uint8_t buffer[4];
uint32_t value;
reg= (reg << 8) + (reg >> 8);
i2c->write_blocking(address, regbuf, 2, true);
i2c->read_blocking(address, buffer, 4, false);
value= (buffer[0] << 24) + (buffer[1] << 16) + (buffer[2] << 8) + buffer[3];
return value;
}
// set distance mode to Short, Medium, or Long
// based on VL53L1_SetDistanceMode()
bool VL53L1X::setDistanceMode(DistanceMode mode)
{
// save existing timing budget
uint32_t budget_us = getMeasurementTimingBudget();
switch (mode)
{
case Short:
// from VL53L1_preset_mode_standard_ranging_short_range()
// timing config
writeReg(RANGE_CONFIG__VCSEL_PERIOD_A, 0x07);
writeReg(RANGE_CONFIG__VCSEL_PERIOD_B, 0x05);
writeReg(RANGE_CONFIG__VALID_PHASE_HIGH, 0x38);
// dynamic config
writeReg(SD_CONFIG__WOI_SD0, 0x07);
writeReg(SD_CONFIG__WOI_SD1, 0x05);
writeReg(SD_CONFIG__INITIAL_PHASE_SD0, 6); // tuning parm default
writeReg(SD_CONFIG__INITIAL_PHASE_SD1, 6); // tuning parm default
break;
case Medium:
// from VL53L1_preset_mode_standard_ranging()
// timing config
writeReg(RANGE_CONFIG__VCSEL_PERIOD_A, 0x0B);
writeReg(RANGE_CONFIG__VCSEL_PERIOD_B, 0x09);
writeReg(RANGE_CONFIG__VALID_PHASE_HIGH, 0x78);
// dynamic config
writeReg(SD_CONFIG__WOI_SD0, 0x0B);
writeReg(SD_CONFIG__WOI_SD1, 0x09);
writeReg(SD_CONFIG__INITIAL_PHASE_SD0, 10); // tuning parm default
writeReg(SD_CONFIG__INITIAL_PHASE_SD1, 10); // tuning parm default
break;
case Long: // long
// from VL53L1_preset_mode_standard_ranging_long_range()
// timing config
writeReg(RANGE_CONFIG__VCSEL_PERIOD_A, 0x0F);
writeReg(RANGE_CONFIG__VCSEL_PERIOD_B, 0x0D);
writeReg(RANGE_CONFIG__VALID_PHASE_HIGH, 0xB8);
// dynamic config
writeReg(SD_CONFIG__WOI_SD0, 0x0F);
writeReg(SD_CONFIG__WOI_SD1, 0x0D);
writeReg(SD_CONFIG__INITIAL_PHASE_SD0, 14); // tuning parm default
writeReg(SD_CONFIG__INITIAL_PHASE_SD1, 14); // tuning parm default
break;
default:
// unrecognized mode - do nothing
return false;
}
// reapply timing budget
setMeasurementTimingBudget(budget_us);
// save mode so it can be returned by getDistanceMode()
distance_mode = mode;
return true;
}
bool VL53L1X::setDistanceModeInt(uint8_t mode)
{
// Map the mode here to the internal Enum - must be a better way!
switch (mode)
{
case 0:
// Do nothing
break;
case 1:
setDistanceMode(Short);
break;
case 2:
setDistanceMode(Medium);
break;
case 3:
setDistanceMode(Long);
break;
}
return true;
}
// Set the measurement timing budget in microseconds, which is the time allowed
// for one measurement. A longer timing budget allows for more accurate
// measurements.
// based on VL53L1_SetMeasurementTimingBudgetMicroSeconds()
bool VL53L1X::setMeasurementTimingBudget(uint32_t budget_us)
{
// assumes PresetMode is LOWPOWER_AUTONOMOUS
if (budget_us <= TimingGuard) { return false; }
uint32_t range_config_timeout_us = budget_us -= TimingGuard;
if (range_config_timeout_us > 1100000) { return false; } // FDA_MAX_TIMING_BUDGET_US * 2
range_config_timeout_us /= 2;
// VL53L1_calc_timeout_register_values() begin
uint32_t macro_period_us;
// "Update Macro Period for Range A VCSEL Period"
macro_period_us = calcMacroPeriod(readReg(RANGE_CONFIG__VCSEL_PERIOD_A));
// "Update Phase timeout - uses Timing A"
// Timeout of 1000 is tuning parm default (TIMED_PHASECAL_CONFIG_TIMEOUT_US_DEFAULT)
// via VL53L1_get_preset_mode_timing_cfg().
uint32_t phasecal_timeout_mclks = timeoutMicrosecondsToMclks(1000, macro_period_us);
if (phasecal_timeout_mclks > 0xFF) { phasecal_timeout_mclks = 0xFF; }
writeReg(PHASECAL_CONFIG__TIMEOUT_MACROP, phasecal_timeout_mclks);
// "Update MM Timing A timeout"
// Timeout of 1 is tuning parm default (LOWPOWERAUTO_MM_CONFIG_TIMEOUT_US_DEFAULT)
// via VL53L1_get_preset_mode_timing_cfg(). With the API, the register
// actually ends up with a slightly different value because it gets assigned,
// retrieved, recalculated with a different macro period, and reassigned,
// but it probably doesn't matter because it seems like the MM ("mode
// mitigation"?) sequence steps are disabled in low power auto mode anyway.
writeReg16Bit(MM_CONFIG__TIMEOUT_MACROP_A, encodeTimeout(
timeoutMicrosecondsToMclks(1, macro_period_us)));
// "Update Range Timing A timeout"
writeReg16Bit(RANGE_CONFIG__TIMEOUT_MACROP_A, encodeTimeout(
timeoutMicrosecondsToMclks(range_config_timeout_us, macro_period_us)));
// "Update Macro Period for Range B VCSEL Period"
macro_period_us = calcMacroPeriod(readReg(RANGE_CONFIG__VCSEL_PERIOD_B));
// "Update MM Timing B timeout"
// (See earlier comment about MM Timing A timeout.)
writeReg16Bit(MM_CONFIG__TIMEOUT_MACROP_B, encodeTimeout(
timeoutMicrosecondsToMclks(1, macro_period_us)));
// "Update Range Timing B timeout"
writeReg16Bit(RANGE_CONFIG__TIMEOUT_MACROP_B, encodeTimeout(
timeoutMicrosecondsToMclks(range_config_timeout_us, macro_period_us)));
// VL53L1_calc_timeout_register_values() end
return true;
}
// Get the measurement timing budget in microseconds
// based on VL53L1_SetMeasurementTimingBudgetMicroSeconds()
uint32_t VL53L1X::getMeasurementTimingBudget()
{
// assumes PresetMode is LOWPOWER_AUTONOMOUS and these sequence steps are
// enabled: VHV, PHASECAL, DSS1, RANGE
// VL53L1_get_timeouts_us() begin
// "Update Macro Period for Range A VCSEL Period"
uint32_t macro_period_us = calcMacroPeriod(readReg(RANGE_CONFIG__VCSEL_PERIOD_A));
// "Get Range Timing A timeout"
uint32_t range_config_timeout_us = timeoutMclksToMicroseconds(decodeTimeout(
readReg16Bit(RANGE_CONFIG__TIMEOUT_MACROP_A)), macro_period_us);
// VL53L1_get_timeouts_us() end
return 2 * range_config_timeout_us + TimingGuard;
}
// Start continuous ranging measurements, with the given inter-measurement
// period in milliseconds determining how often the sensor takes a measurement.
void VL53L1X::startContinuous(uint32_t period_ms)
{
// from VL53L1_set_inter_measurement_period_ms()
writeReg32Bit(SYSTEM__INTERMEASUREMENT_PERIOD, period_ms * osc_calibrate_val);
writeReg(SYSTEM__INTERRUPT_CLEAR, 0x01); // sys_interrupt_clear_range
writeReg(SYSTEM__MODE_START, 0x40); // mode_range__timed
}
// Stop continuous measurements
// based on VL53L1_stop_range()
void VL53L1X::stopContinuous()
{
writeReg(SYSTEM__MODE_START, 0x80); // mode_range__abort
// VL53L1_low_power_auto_data_stop_range() begin
calibrated = false;
// "restore vhv configs"
if (saved_vhv_init != 0)
{
writeReg(VHV_CONFIG__INIT, saved_vhv_init);
}
if (saved_vhv_timeout != 0)
{
writeReg(VHV_CONFIG__TIMEOUT_MACROP_LOOP_BOUND, saved_vhv_timeout);
}
// "remove phasecal override"
writeReg(PHASECAL_CONFIG__OVERRIDE, 0x00);
// VL53L1_low_power_auto_data_stop_range() end
}
// Returns a range reading in millimeters when continuous mode is active. If
// blocking is true (the default), this function waits for a new measurement to
// be available. If blocking is false, it will try to return data immediately.
// (readSingle() also calls this function after starting a single-shot range
// measurement)
uint16_t VL53L1X::read(bool blocking)
{
if (blocking)
{
startTimeout();
while (!dataReady())
{
if (checkTimeoutExpired())
{
did_timeout = true;
return 0;
}
sleep_us(100);
}
}
readResults();
if (!calibrated)
{
setupManualCalibration();
calibrated = true;
}
updateDSS();
getRangingData();
writeReg(SYSTEM__INTERRUPT_CLEAR, 0x01); // sys_interrupt_clear_range
return ranging_data.range_mm;
}
// Starts a single-shot range measurement. If blocking is true (the default),
// this function waits for the measurement to finish and returns the reading.
// Otherwise, it returns 0 immediately.
uint16_t VL53L1X::readSingle(bool blocking)
{
writeReg(SYSTEM__INTERRUPT_CLEAR, 0x01); // sys_interrupt_clear_range
writeReg(SYSTEM__MODE_START, 0x10); // mode_range__single_shot
if (blocking)
{
return read(true);
}
else
{
return 0;
}
}
// convert a RangeStatus to a readable string
// Note that on an AVR, these strings are stored in RAM (dynamic memory), which
// makes working with them easier but uses up 200+ bytes of RAM (many AVR-based
// Arduinos only have about 2000 bytes of RAM). You can avoid this memory usage
// if you do not call this function in your sketch.
const char * VL53L1X::rangeStatusToString(RangeStatus status)
{
switch (status)
{
case RangeValid:
return "range valid";
case SigmaFail:
return "sigma fail";
case SignalFail:
return "signal fail";
case RangeValidMinRangeClipped:
return "range valid, min range clipped";
case OutOfBoundsFail:
return "out of bounds fail";
case HardwareFail:
return "hardware fail";
case RangeValidNoWrapCheckFail:
return "range valid, no wrap check fail";
case WrapTargetFail:
return "wrap target fail";
case XtalkSignalFail:
return "xtalk signal fail";
case SynchronizationInt:
return "synchronization int";
case MinRangeFail:
return "min range fail";
case None:
return "no update";
default:
return "unknown status";
}
}
// Did a timeout occur in one of the read functions since the last call to
// timeoutOccurred()?
bool VL53L1X::timeoutOccurred()
{
bool tmp = did_timeout;
did_timeout = false;
return tmp;
}
// Private Methods /////////////////////////////////////////////////////////////
// "Setup ranges after the first one in low power auto mode by turning off
// FW calibration steps and programming static values"
// based on VL53L1_low_power_auto_setup_manual_calibration()
void VL53L1X::setupManualCalibration()
{
// "save original vhv configs"
saved_vhv_init = readReg(VHV_CONFIG__INIT);
saved_vhv_timeout = readReg(VHV_CONFIG__TIMEOUT_MACROP_LOOP_BOUND);
// "disable VHV init"
writeReg(VHV_CONFIG__INIT, saved_vhv_init & 0x7F);
// "set loop bound to tuning param"
writeReg(VHV_CONFIG__TIMEOUT_MACROP_LOOP_BOUND,
(saved_vhv_timeout & 0x03) + (3 << 2)); // tuning parm default (LOWPOWERAUTO_VHV_LOOP_BOUND_DEFAULT)
// "override phasecal"
writeReg(PHASECAL_CONFIG__OVERRIDE, 0x01);
writeReg(CAL_CONFIG__VCSEL_START, readReg(PHASECAL_RESULT__VCSEL_START));
}
// read measurement results into buffer
void VL53L1X::readResults()
{
uint16_t reg = RESULT__RANGE_STATUS;
uint8_t regbuf[2] = {(reg >> 8) & 0xFF, reg & 0xFF};
uint8_t buffer[17];
i2c->write_blocking(address, regbuf, 2, true);
i2c->read_blocking(address, buffer, 17, false);
results.range_status = buffer[0];
// bus->read(); // report_status: not used
results.stream_count = buffer[2];
results.dss_actual_effective_spads_sd0 = (uint16_t)buffer[3] << 8; // high byte
results.dss_actual_effective_spads_sd0 |= buffer[4]; // low byte
// bus->read(); // peak_signal_count_rate_mcps_sd0: not used
// bus->read();
results.ambient_count_rate_mcps_sd0 = (uint16_t)buffer[7] << 8; // high byte
results.ambient_count_rate_mcps_sd0 |= buffer[8]; // low byte
// bus->read(); // sigma_sd0: not used
// bus->read();
// bus->read(); // phase_sd0: not used
// bus->read();
results.final_crosstalk_corrected_range_mm_sd0 = (uint16_t)buffer[13] << 8; // high byte
results.final_crosstalk_corrected_range_mm_sd0 |= buffer[14]; // low byte
results.peak_signal_count_rate_crosstalk_corrected_mcps_sd0 = (uint16_t)buffer[15] << 8; // high byte
results.peak_signal_count_rate_crosstalk_corrected_mcps_sd0 |= buffer[16]; // low byte
}
// perform Dynamic SPAD Selection calculation/update
// based on VL53L1_low_power_auto_update_DSS()
void VL53L1X::updateDSS()
{
uint16_t spadCount = results.dss_actual_effective_spads_sd0;
if (spadCount != 0)
{
// "Calc total rate per spad"
uint32_t totalRatePerSpad =
(uint32_t)results.peak_signal_count_rate_crosstalk_corrected_mcps_sd0 +
results.ambient_count_rate_mcps_sd0;
// "clip to 16 bits"
if (totalRatePerSpad > 0xFFFF) { totalRatePerSpad = 0xFFFF; }
// "shift up to take advantage of 32 bits"
totalRatePerSpad <<= 16;
totalRatePerSpad /= spadCount;
if (totalRatePerSpad != 0)
{
// "get the target rate and shift up by 16"
uint32_t requiredSpads = ((uint32_t)TargetRate << 16) / totalRatePerSpad;
// "clip to 16 bit"
if (requiredSpads > 0xFFFF) { requiredSpads = 0xFFFF; }
// "override DSS config"
writeReg16Bit(DSS_CONFIG__MANUAL_EFFECTIVE_SPADS_SELECT, requiredSpads);
// DSS_CONFIG__ROI_MODE_CONTROL should already be set to REQUESTED_EFFFECTIVE_SPADS
return;
}
}
// If we reached this point, it means something above would have resulted in a
// divide by zero.
// "We want to gracefully set a spad target, not just exit with an error"
// "set target to mid point"
writeReg16Bit(DSS_CONFIG__MANUAL_EFFECTIVE_SPADS_SELECT, 0x8000);
}
// get range, status, rates from results buffer
// based on VL53L1_GetRangingMeasurementData()
void VL53L1X::getRangingData()
{
// VL53L1_copy_sys_and_core_results_to_range_results() begin
uint16_t range = results.final_crosstalk_corrected_range_mm_sd0;
// "apply correction gain"
// gain factor of 2011 is tuning parm default (VL53L1_TUNINGPARM_LITE_RANGING_GAIN_FACTOR_DEFAULT)
// Basically, this appears to scale the result by 2011/2048, or about 98%
// (with the 1024 added for proper rounding).
ranging_data.range_mm = ((uint32_t)range * 2011 + 0x0400) / 0x0800;
// VL53L1_copy_sys_and_core_results_to_range_results() end
// set range_status in ranging_data based on value of RESULT__RANGE_STATUS register
// mostly based on ConvertStatusLite()
switch(results.range_status)
{
case 17: // MULTCLIPFAIL
case 2: // VCSELWATCHDOGTESTFAILURE
case 1: // VCSELCONTINUITYTESTFAILURE
case 3: // NOVHVVALUEFOUND
// from SetSimpleData()
ranging_data.range_status = HardwareFail;
break;
case 13: // USERROICLIP
// from SetSimpleData()
ranging_data.range_status = MinRangeFail;
break;
case 18: // GPHSTREAMCOUNT0READY
ranging_data.range_status = SynchronizationInt;
break;
case 5: // RANGEPHASECHECK
ranging_data.range_status = OutOfBoundsFail;
break;
case 4: // MSRCNOTARGET
ranging_data.range_status = SignalFail;
break;
case 6: // SIGMATHRESHOLDCHECK
ranging_data.range_status = SigmaFail;
break;
case 7: // PHASECONSISTENCY
ranging_data.range_status = WrapTargetFail;
break;
case 12: // RANGEIGNORETHRESHOLD
ranging_data.range_status = XtalkSignalFail;
break;
case 8: // MINCLIP
ranging_data.range_status = RangeValidMinRangeClipped;
break;
case 9: // RANGECOMPLETE
// from VL53L1_copy_sys_and_core_results_to_range_results()
if (results.stream_count == 0)
{
ranging_data.range_status = RangeValidNoWrapCheckFail;
}
else
{
ranging_data.range_status = RangeValid;
}
break;
default:
ranging_data.range_status = None;
}
// from SetSimpleData()
ranging_data.peak_signal_count_rate_MCPS =
countRateFixedToFloat(results.peak_signal_count_rate_crosstalk_corrected_mcps_sd0);
ranging_data.ambient_count_rate_MCPS =
countRateFixedToFloat(results.ambient_count_rate_mcps_sd0);
}
// Decode sequence step timeout in MCLKs from register value
// based on VL53L1_decode_timeout()
uint32_t VL53L1X::decodeTimeout(uint16_t reg_val)
{
return ((uint32_t)(reg_val & 0xFF) << (reg_val >> 8)) + 1;
}
// Encode sequence step timeout register value from timeout in MCLKs
// based on VL53L1_encode_timeout()
uint16_t VL53L1X::encodeTimeout(uint32_t timeout_mclks)
{
// encoded format: "(LSByte * 2^MSByte) + 1"
uint32_t ls_byte = 0;
uint16_t ms_byte = 0;
if (timeout_mclks > 0)
{
ls_byte = timeout_mclks - 1;
while ((ls_byte & 0xFFFFFF00) > 0)
{
ls_byte >>= 1;
ms_byte++;
}
return (ms_byte << 8) | (ls_byte & 0xFF);
}
else { return 0; }
}
// Convert sequence step timeout from macro periods to microseconds with given
// macro period in microseconds (12.12 format)
// based on VL53L1_calc_timeout_us()
uint32_t VL53L1X::timeoutMclksToMicroseconds(uint32_t timeout_mclks, uint32_t macro_period_us)
{
return ((uint64_t)timeout_mclks * macro_period_us + 0x800) >> 12;
}
// Convert sequence step timeout from microseconds to macro periods with given
// macro period in microseconds (12.12 format)
// based on VL53L1_calc_timeout_mclks()
uint32_t VL53L1X::timeoutMicrosecondsToMclks(uint32_t timeout_us, uint32_t macro_period_us)
{
return (((uint32_t)timeout_us << 12) + (macro_period_us >> 1)) / macro_period_us;
}
// Calculate macro period in microseconds (12.12 format) with given VCSEL period
// assumes fast_osc_frequency has been read and stored
// based on VL53L1_calc_macro_period_us()
uint32_t VL53L1X::calcMacroPeriod(uint8_t vcsel_period)
{
// from VL53L1_calc_pll_period_us()
// fast osc frequency in 4.12 format; PLL period in 0.24 format
uint32_t pll_period_us = ((uint32_t)0x01 << 30) / fast_osc_frequency;
// from VL53L1_decode_vcsel_period()
uint8_t vcsel_period_pclks = (vcsel_period + 1) << 1;
// VL53L1_MACRO_PERIOD_VCSEL_PERIODS = 2304
uint32_t macro_period_us = (uint32_t)2304 * pll_period_us;
macro_period_us >>= 6;
macro_period_us *= vcsel_period_pclks;
macro_period_us >>= 6;
return macro_period_us;
}
}
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