#ifndef SENS_VL53L0X_H #define SENS_VL53L0X_H #include "../../io/SoftI2C.h" #include "../../Debug.h" /** * TOF distance measurement sensor * * there seems to be no register-map from the vendor. only a poor API.. * used values from this library: * https://github.com/pololu/vl53l0x-arduino/blob/master/VL53L0X.h * https://github.com/pololu/vl53l0x-arduino/blob/master/VL53L0X.cpp */ class VL53L0X { private: static constexpr const char* NAME = "VL53L0X"; static constexpr uint8_t ADDR = 0b0101001 ; bool inited = false; enum Register { SYSRANGE_START = 0x00, SYSTEM_THRESH_HIGH = 0x0C, SYSTEM_THRESH_LOW = 0x0E, SYSTEM_SEQUENCE_CONFIG = 0x01, SYSTEM_RANGE_CONFIG = 0x09, SYSTEM_INTERMEASUREMENT_PERIOD = 0x04, SYSTEM_INTERRUPT_CONFIG_GPIO = 0x0A, GPIO_HV_MUX_ACTIVE_HIGH = 0x84, SYSTEM_INTERRUPT_CLEAR = 0x0B, RESULT_INTERRUPT_STATUS = 0x13, RESULT_RANGE_STATUS = 0x14, RESULT_CORE_AMBIENT_WINDOW_EVENTS_RTN = 0xBC, RESULT_CORE_RANGING_TOTAL_EVENTS_RTN = 0xC0, RESULT_CORE_AMBIENT_WINDOW_EVENTS_REF = 0xD0, RESULT_CORE_RANGING_TOTAL_EVENTS_REF = 0xD4, RESULT_PEAK_SIGNAL_RATE_REF = 0xB6, ALGO_PART_TO_PART_RANGE_OFFSET_MM = 0x28, I2C_SLAVE_DEVICE_ADDRESS = 0x8A, MSRC_CONFIG_CONTROL = 0x60, PRE_RANGE_CONFIG_MIN_SNR = 0x27, PRE_RANGE_CONFIG_VALID_PHASE_LOW = 0x56, PRE_RANGE_CONFIG_VALID_PHASE_HIGH = 0x57, PRE_RANGE_MIN_COUNT_RATE_RTN_LIMIT = 0x64, FINAL_RANGE_CONFIG_MIN_SNR = 0x67, FINAL_RANGE_CONFIG_VALID_PHASE_LOW = 0x47, FINAL_RANGE_CONFIG_VALID_PHASE_HIGH = 0x48, FINAL_RANGE_CONFIG_MIN_COUNT_RATE_RTN_LIMIT = 0x44, PRE_RANGE_CONFIG_SIGMA_THRESH_HI = 0x61, PRE_RANGE_CONFIG_SIGMA_THRESH_LO = 0x62, PRE_RANGE_CONFIG_VCSEL_PERIOD = 0x50, PRE_RANGE_CONFIG_TIMEOUT_MACROP_HI = 0x51, PRE_RANGE_CONFIG_TIMEOUT_MACROP_LO = 0x52, SYSTEM_HISTOGRAM_BIN = 0x81, HISTOGRAM_CONFIG_INITIAL_PHASE_SELECT = 0x33, HISTOGRAM_CONFIG_READOUT_CTRL = 0x55, FINAL_RANGE_CONFIG_VCSEL_PERIOD = 0x70, FINAL_RANGE_CONFIG_TIMEOUT_MACROP_HI = 0x71, FINAL_RANGE_CONFIG_TIMEOUT_MACROP_LO = 0x72, CROSSTALK_COMPENSATION_PEAK_RATE_MCPS = 0x20, MSRC_CONFIG_TIMEOUT_MACROP = 0x46, SOFT_RESET_GO2_SOFT_RESET_N = 0xBF, IDENTIFICATION_MODEL_ID = 0xC0, IDENTIFICATION_REVISION_ID = 0xC2, OSC_CALIBRATE_VAL = 0xF8, GLOBAL_CONFIG_VCSEL_WIDTH = 0x32, GLOBAL_CONFIG_SPAD_ENABLES_REF_0 = 0xB0, GLOBAL_CONFIG_SPAD_ENABLES_REF_1 = 0xB1, GLOBAL_CONFIG_SPAD_ENABLES_REF_2 = 0xB2, GLOBAL_CONFIG_SPAD_ENABLES_REF_3 = 0xB3, GLOBAL_CONFIG_SPAD_ENABLES_REF_4 = 0xB4, GLOBAL_CONFIG_SPAD_ENABLES_REF_5 = 0xB5, GLOBAL_CONFIG_REF_EN_START_SELECT = 0xB6, DYNAMIC_SPAD_NUM_REQUESTED_REF_SPAD = 0x4E, DYNAMIC_SPAD_REF_EN_START_OFFSET = 0x4F, POWER_MANAGEMENT_GO1_POWER_FORCE = 0x80, VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV = 0x89, ALGO_PHASECAL_LIM = 0x30, ALGO_PHASECAL_CONFIG_TIMEOUT = 0x30, }; // Calculate macro period in *nanoseconds* from VCSEL period in PCLKs // based on VL53L0X_calc_macro_period_ps() // PLL_period_ps = 1655; macro_period_vclks = 2304 #define calcMacroPeriod(vcsel_period_pclks) ((((uint32_t)2304 * (vcsel_period_pclks) * 1655) + 500) / 1000) // Decode VCSEL (vertical cavity surface emitting laser) pulse period in PCLKs // from register value // based on VL53L0X_decode_vcsel_period() #define decodeVcselPeriod(reg_val) (((reg_val) + 1) << 1) // Encode VCSEL pulse period register value from period in PCLKs // based on VL53L0X_encode_vcsel_period() #define encodeVcselPeriod(period_pclks) (((period_pclks) >> 1) - 1) uint8_t stop_variable; uint32_t measurement_timing_budget_us; struct SequenceStepEnables { bool tcc, msrc, dss, pre_range, final_range; }; struct SequenceStepTimeouts { uint16_t pre_range_vcsel_period_pclks, final_range_vcsel_period_pclks; uint16_t msrc_dss_tcc_mclks, pre_range_mclks, final_range_mclks; uint32_t msrc_dss_tcc_us, pre_range_us, final_range_us; }; enum vcselPeriodType { VcselPeriodPreRange, VcselPeriodFinalRange }; private: bool init() { debugMod(NAME, "init()"); // VL53L0X_DataInit() begin // // sensor uses 1V8 mode for I/O by default; switch to 2V8 mode if necessary // if (io_2v8) // { // writeReg8(VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV, // readReg8(VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV) | 0x01); // set bit 0 // } // "Set I2C standard mode" writeReg8(0x88, 0x00); writeReg8(0x80, 0x01); writeReg8(0xFF, 0x01); writeReg8(0x00, 0x00); stop_variable = readReg8(0x91); writeReg8(0x00, 0x01); writeReg8(0xFF, 0x00); writeReg8(0x80, 0x00); // disable SIGNAL_RATE_MSRC (bit 1) and SIGNAL_RATE_PRE_RANGE (bit 4) limit checks writeReg8(MSRC_CONFIG_CONTROL, readReg8(MSRC_CONFIG_CONTROL) | 0x12); // set final range signal rate limit to 0.25 MCPS (million counts per second) ////////setSignalRateLimit(0.25); writeReg8(SYSTEM_SEQUENCE_CONFIG, 0xFF); // VL53L0X_DataInit() end // VL53L0X_StaticInit() begin debugMod(NAME, "getting SPAD info"); uint8_t spad_count; bool spad_type_is_aperture; if (!getSpadInfo(&spad_count, &spad_type_is_aperture)) { debugMod(NAME, "failed to get SPAD info"); return false; } // The SPAD map (RefGoodSpadMap) is read by VL53L0X_get_info_from_device() in // the API, but the same data seems to be more easily readable from // GLOBAL_CONFIG_SPAD_ENABLES_REF_0 through _6, so read it from there uint8_t ref_spad_map[6]; readRegN(GLOBAL_CONFIG_SPAD_ENABLES_REF_0, ref_spad_map, 6); // -- VL53L0X_set_reference_spads() begin (assume NVM values are valid) writeReg8(0xFF, 0x01); writeReg8(DYNAMIC_SPAD_REF_EN_START_OFFSET, 0x00); writeReg8(DYNAMIC_SPAD_NUM_REQUESTED_REF_SPAD, 0x2C); writeReg8(0xFF, 0x00); writeReg8(GLOBAL_CONFIG_REF_EN_START_SELECT, 0xB4); uint8_t first_spad_to_enable = spad_type_is_aperture ? 12 : 0; // 12 is the first aperture spad uint8_t spads_enabled = 0; for (uint8_t i = 0; i < 48; i++) { if (i < first_spad_to_enable || spads_enabled == spad_count) { // This bit is lower than the first one that should be enabled, or // (reference_spad_count) bits have already been enabled, so zero this bit ref_spad_map[i / 8] &= ~(1 << (i % 8)); } else if ((ref_spad_map[i / 8] >> (i % 8)) & 0x1) { spads_enabled++; } } debugMod1(NAME, "enabled SPADs: %d", spads_enabled); writeRegN(GLOBAL_CONFIG_SPAD_ENABLES_REF_0, ref_spad_map, 6); // -- VL53L0X_set_reference_spads() end // -- VL53L0X_load_tuning_settings() begin // DefaultTuningSettings from vl53l0x_tuning.h writeReg8(0xFF, 0x01); writeReg8(0x00, 0x00); writeReg8(0xFF, 0x00); writeReg8(0x09, 0x00); writeReg8(0x10, 0x00); writeReg8(0x11, 0x00); writeReg8(0x24, 0x01); writeReg8(0x25, 0xFF); writeReg8(0x75, 0x00); writeReg8(0xFF, 0x01); writeReg8(0x4E, 0x2C); writeReg8(0x48, 0x00); writeReg8(0x30, 0x20); writeReg8(0xFF, 0x00); writeReg8(0x30, 0x09); writeReg8(0x54, 0x00); writeReg8(0x31, 0x04); writeReg8(0x32, 0x03); writeReg8(0x40, 0x83); writeReg8(0x46, 0x25); writeReg8(0x60, 0x00); writeReg8(0x27, 0x00); writeReg8(0x50, 0x06); writeReg8(0x51, 0x00); writeReg8(0x52, 0x96); writeReg8(0x56, 0x08); writeReg8(0x57, 0x30); writeReg8(0x61, 0x00); writeReg8(0x62, 0x00); writeReg8(0x64, 0x00); writeReg8(0x65, 0x00); writeReg8(0x66, 0xA0); writeReg8(0xFF, 0x01); writeReg8(0x22, 0x32); writeReg8(0x47, 0x14); writeReg8(0x49, 0xFF); writeReg8(0x4A, 0x00); writeReg8(0xFF, 0x00); writeReg8(0x7A, 0x0A); writeReg8(0x7B, 0x00); writeReg8(0x78, 0x21); writeReg8(0xFF, 0x01); writeReg8(0x23, 0x34); writeReg8(0x42, 0x00); writeReg8(0x44, 0xFF); writeReg8(0x45, 0x26); writeReg8(0x46, 0x05); writeReg8(0x40, 0x40); writeReg8(0x0E, 0x06); writeReg8(0x20, 0x1A); writeReg8(0x43, 0x40); writeReg8(0xFF, 0x00); writeReg8(0x34, 0x03); writeReg8(0x35, 0x44); writeReg8(0xFF, 0x01); writeReg8(0x31, 0x04); writeReg8(0x4B, 0x09); writeReg8(0x4C, 0x05); writeReg8(0x4D, 0x04); writeReg8(0xFF, 0x00); writeReg8(0x44, 0x00); writeReg8(0x45, 0x20); writeReg8(0x47, 0x08); writeReg8(0x48, 0x28); writeReg8(0x67, 0x00); writeReg8(0x70, 0x04); writeReg8(0x71, 0x01); writeReg8(0x72, 0xFE); writeReg8(0x76, 0x00); writeReg8(0x77, 0x00); writeReg8(0xFF, 0x01); writeReg8(0x0D, 0x01); writeReg8(0xFF, 0x00); writeReg8(0x80, 0x01); writeReg8(0x01, 0xF8); writeReg8(0xFF, 0x01); writeReg8(0x8E, 0x01); writeReg8(0x00, 0x01); writeReg8(0xFF, 0x00); writeReg8(0x80, 0x00); // -- VL53L0X_load_tuning_settings() end // "Set interrupt config to new sample ready" // -- VL53L0X_SetGpioConfig() begin writeReg8(SYSTEM_INTERRUPT_CONFIG_GPIO, 0x04); writeReg8(GPIO_HV_MUX_ACTIVE_HIGH, readReg8(GPIO_HV_MUX_ACTIVE_HIGH) & ~0x10); // active low writeReg8(SYSTEM_INTERRUPT_CLEAR, 0x01); // -- VL53L0X_SetGpioConfig() end measurement_timing_budget_us = getMeasurementTimingBudget(); debugMod1(NAME, "timing budget: %d", measurement_timing_budget_us) // "Disable MSRC and TCC by default" // MSRC = Minimum Signal Rate Check // TCC = Target CentreCheck // -- VL53L0X_SetSequenceStepEnable() begin writeReg8(SYSTEM_SEQUENCE_CONFIG, 0xE8); // -- VL53L0X_SetSequenceStepEnable() end // KAZU setVcselPulsePeriod(VcselPeriodPreRange, 18); setVcselPulsePeriod(VcselPeriodFinalRange, 14); // "Recalculate timing budget" debugMod(NAME, "new setting timing budget"); bool ok = setMeasurementTimingBudget(measurement_timing_budget_us); if (!ok) { debugMod(NAME, "failed to set timing budget"); return false; } // VL53L0X_StaticInit() end // VL53L0X_PerformRefCalibration() begin (VL53L0X_perform_ref_calibration()) // -- VL53L0X_perform_vhv_calibration() begin debugMod(NAME, "VHV calibration"); writeReg8(SYSTEM_SEQUENCE_CONFIG, 0x01); if (!performSingleRefCalibration(0x40)) { debugMod(NAME, "VHV calibration failed"); return false; } else { debugMod(NAME, "VHV calibration OK"); } // -- VL53L0X_perform_vhv_calibration() end // -- VL53L0X_perform_phase_calibration() begin debugMod(NAME, "PHASE calibration"); writeReg8(SYSTEM_SEQUENCE_CONFIG, 0x02); if (!performSingleRefCalibration(0x00)) { debugMod(NAME, "PHASE calibration failed"); return false; } else { debugMod(NAME, "PHASE calibration OK"); } // -- VL53L0X_perform_phase_calibration() end // "restore the previous Sequence Config" writeReg8(SYSTEM_SEQUENCE_CONFIG, 0xE8); // VL53L0X_PerformRefCalibration() end return true; } // Get reference SPAD (single photon avalanche diode) count and type // based on VL53L0X_get_info_from_device(), // but only gets reference SPAD count and type bool getSpadInfo(uint8_t * count, bool * type_is_aperture) { uint8_t tmp; writeReg8(0x80, 0x01); writeReg8(0xFF, 0x01); writeReg8(0x00, 0x00); writeReg8(0xFF, 0x06); writeReg8(0x83, readReg8(0x83) | 0x04); writeReg8(0xFF, 0x07); writeReg8(0x81, 0x01); writeReg8(0x80, 0x01); writeReg8(0x94, 0x6b); writeReg8(0x83, 0x00); int cnt = 0; while (readReg8(0x83) == 0x00) { if (++cnt > 100) { debugMod(NAME, "SPAD timeout"); return false; } } writeReg8(0x83, 0x01); tmp = readReg8(0x92); *count = tmp & 0x7f; *type_is_aperture = (tmp >> 7) & 0x01; writeReg8(0x81, 0x00); writeReg8(0xFF, 0x06); writeReg8(0x83, readReg8(0x83) & ~0x04); writeReg8(0xFF, 0x01); writeReg8(0x00, 0x01); writeReg8(0xFF, 0x00); writeReg8(0x80, 0x00); return true; } // Get the measurement timing budget in microseconds // based on VL53L0X_get_measurement_timing_budget_micro_seconds() // in us uint32_t getMeasurementTimingBudget(void) { SequenceStepEnables enables; SequenceStepTimeouts timeouts; uint16_t const StartOverhead = 1910; // note that this is different than the value in set_ uint16_t const EndOverhead = 960; uint16_t const MsrcOverhead = 660; uint16_t const TccOverhead = 590; uint16_t const DssOverhead = 690; uint16_t const PreRangeOverhead = 660; uint16_t const FinalRangeOverhead = 550; // "Start and end overhead times always present" uint32_t budget_us = StartOverhead + EndOverhead; getSequenceStepEnables(&enables); getSequenceStepTimeouts(&enables, &timeouts); if (enables.tcc) { budget_us += (timeouts.msrc_dss_tcc_us + TccOverhead); } if (enables.dss) { budget_us += 2 * (timeouts.msrc_dss_tcc_us + DssOverhead); } else if (enables.msrc) { budget_us += (timeouts.msrc_dss_tcc_us + MsrcOverhead); } if (enables.pre_range) { budget_us += (timeouts.pre_range_us + PreRangeOverhead); } if (enables.final_range) { budget_us += (timeouts.final_range_us + FinalRangeOverhead); } measurement_timing_budget_us = budget_us; // store for internal reuse return budget_us; } // Set the measurement timing budget in microseconds, which is the time allowed // for one measurement; the ST API and this library take care of splitting the // timing budget among the sub-steps in the ranging sequence. A longer timing // budget allows for more accurate measurements. Increasing the budget by a // factor of N decreases the range measurement standard deviation by a factor of // sqrt(N). Defaults to about 33 milliseconds; the minimum is 20 ms. // based on VL53L0X_set_measurement_timing_budget_micro_seconds() bool setMeasurementTimingBudget(uint32_t budget_us) { SequenceStepEnables enables; SequenceStepTimeouts timeouts; uint16_t const StartOverhead = 1320; // note that this is different than the value in get_ uint16_t const EndOverhead = 960; uint16_t const MsrcOverhead = 660; uint16_t const TccOverhead = 590; uint16_t const DssOverhead = 690; uint16_t const PreRangeOverhead = 660; uint16_t const FinalRangeOverhead = 550; uint32_t const MinTimingBudget = 20000; if (budget_us < MinTimingBudget) { return false; } uint32_t used_budget_us = StartOverhead + EndOverhead; getSequenceStepEnables(&enables); getSequenceStepTimeouts(&enables, &timeouts); if (enables.tcc) { used_budget_us += (timeouts.msrc_dss_tcc_us + TccOverhead); } if (enables.dss) { used_budget_us += 2 * (timeouts.msrc_dss_tcc_us + DssOverhead); } else if (enables.msrc) { used_budget_us += (timeouts.msrc_dss_tcc_us + MsrcOverhead); } if (enables.pre_range) { used_budget_us += (timeouts.pre_range_us + PreRangeOverhead); } if (enables.final_range) { used_budget_us += FinalRangeOverhead; // "Note that the final range timeout is determined by the timing // budget and the sum of all other timeouts within the sequence. // If there is no room for the final range timeout, then an error // will be set. Otherwise the remaining time will be applied to // the final range." if (used_budget_us > budget_us) { // "Requested timeout too big." return false; } uint32_t final_range_timeout_us = budget_us - used_budget_us; // set_sequence_step_timeout() begin // (SequenceStepId == VL53L0X_SEQUENCESTEP_FINAL_RANGE) // "For the final range timeout, the pre-range timeout // must be added. To do this both final and pre-range // timeouts must be expressed in macro periods MClks // because they have different vcsel periods." uint16_t final_range_timeout_mclks = timeoutMicrosecondsToMclks(final_range_timeout_us, timeouts.final_range_vcsel_period_pclks); if (enables.pre_range) { final_range_timeout_mclks += timeouts.pre_range_mclks; } writeReg16(FINAL_RANGE_CONFIG_TIMEOUT_MACROP_HI, encodeTimeout(final_range_timeout_mclks)); // set_sequence_step_timeout() end measurement_timing_budget_us = budget_us; // store for internal reuse } return true; } // Get sequence step enables // based on VL53L0X_GetSequenceStepEnables() void getSequenceStepEnables(SequenceStepEnables* enables) { uint8_t sequence_config = readReg8(SYSTEM_SEQUENCE_CONFIG); enables->tcc = (sequence_config >> 4) & 0x1; enables->dss = (sequence_config >> 3) & 0x1; enables->msrc = (sequence_config >> 2) & 0x1; enables->pre_range = (sequence_config >> 6) & 0x1; enables->final_range = (sequence_config >> 7) & 0x1; } // Get sequence step timeouts // based on get_sequence_step_timeout(), // but gets all timeouts instead of just the requested one, and also stores // intermediate values void getSequenceStepTimeouts(SequenceStepEnables const* enables, SequenceStepTimeouts* timeouts) { timeouts->pre_range_vcsel_period_pclks = getVcselPulsePeriod(VcselPeriodPreRange); timeouts->msrc_dss_tcc_mclks = readReg8(MSRC_CONFIG_TIMEOUT_MACROP) + 1; timeouts->msrc_dss_tcc_us = timeoutMclksToMicroseconds(timeouts->msrc_dss_tcc_mclks, timeouts->pre_range_vcsel_period_pclks); timeouts->pre_range_mclks = decodeTimeout(readReg16(PRE_RANGE_CONFIG_TIMEOUT_MACROP_HI)); timeouts->pre_range_us = timeoutMclksToMicroseconds(timeouts->pre_range_mclks, timeouts->pre_range_vcsel_period_pclks); timeouts->final_range_vcsel_period_pclks = getVcselPulsePeriod(VcselPeriodFinalRange); timeouts->final_range_mclks = decodeTimeout(readReg16(FINAL_RANGE_CONFIG_TIMEOUT_MACROP_HI)); if (enables->pre_range) { timeouts->final_range_mclks -= timeouts->pre_range_mclks; } timeouts->final_range_us = timeoutMclksToMicroseconds(timeouts->final_range_mclks, timeouts->final_range_vcsel_period_pclks); debugMod2(NAME, "current timing is pre: %d, final: %d", timeouts->pre_range_vcsel_period_pclks, timeouts->final_range_vcsel_period_pclks); } // based on VL53L0X_perform_single_ref_calibration() bool performSingleRefCalibration(uint8_t vhv_init_byte) { writeReg8(SYSRANGE_START, 0x01 | vhv_init_byte); // VL53L0X_REG_SYSRANGE_MODE_START_STOP int cnt = 0; while ((readReg8(RESULT_INTERRUPT_STATUS) & 0x07) == 0) { if (++cnt > 100) { debugMod(NAME, "calibration timeout"); return false; } } writeReg8(SYSTEM_INTERRUPT_CLEAR, 0x01); writeReg8(SYSRANGE_START, 0x00); return true; } // Convert sequence step timeout from MCLKs to microseconds with given VCSEL period in PCLKs // based on VL53L0X_calc_timeout_us() uint32_t timeoutMclksToMicroseconds(uint16_t timeout_period_mclks, uint8_t vcsel_period_pclks) { uint32_t macro_period_ns = calcMacroPeriod(vcsel_period_pclks); return ((timeout_period_mclks * macro_period_ns) + (macro_period_ns / 2)) / 1000; } // Convert sequence step timeout from microseconds to MCLKs with given VCSEL period in PCLKs // based on VL53L0X_calc_timeout_mclks() uint32_t timeoutMicrosecondsToMclks(uint32_t timeout_period_us, uint8_t vcsel_period_pclks) { uint32_t macro_period_ns = calcMacroPeriod(vcsel_period_pclks); return (((timeout_period_us * 1000) + (macro_period_ns / 2)) / macro_period_ns); } // Get the VCSEL pulse period in PCLKs for the given period type. // based on VL53L0X_get_vcsel_pulse_period() uint8_t getVcselPulsePeriod(vcselPeriodType type) { if (type == VcselPeriodPreRange) { return decodeVcselPeriod(readReg8(PRE_RANGE_CONFIG_VCSEL_PERIOD)); } else if (type == VcselPeriodFinalRange) { return decodeVcselPeriod(readReg8(FINAL_RANGE_CONFIG_VCSEL_PERIOD)); } else { return 255; } } // Decode sequence step timeout in MCLKs from register value // based on VL53L0X_decode_timeout() // Note: the original function returned a uint32_t, but the return value is // always stored in a uint16_t. uint16_t decodeTimeout(uint16_t reg_val) { // format: "(LSByte * 2^MSByte) + 1" return (uint16_t)((reg_val & 0x00FF) << (uint16_t)((reg_val & 0xFF00) >> 8)) + 1; } // Encode sequence step timeout register value from timeout in MCLKs // based on VL53L0X_encode_timeout() // Note: the original function took a uint16_t, but the argument passed to it // is always a uint16_t. uint16_t encodeTimeout(uint16_t timeout_mclks) { // 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; } } // Set the VCSEL (vertical cavity surface emitting laser) pulse period for the // given period type (pre-range or final range) to the given value in PCLKs. // Longer periods seem to increase the potential range of the sensor. // Valid values are (even numbers only): // pre: 12 to 18 (initialized default: 14) // final: 8 to 14 (initialized default: 10) // based on VL53L0X_set_vcsel_pulse_period() bool setVcselPulsePeriod(vcselPeriodType type, uint8_t period_pclks) { uint8_t vcsel_period_reg = encodeVcselPeriod(period_pclks); SequenceStepEnables enables; SequenceStepTimeouts timeouts; getSequenceStepEnables(&enables); getSequenceStepTimeouts(&enables, &timeouts); // "Apply specific settings for the requested clock period" // "Re-calculate and apply timeouts, in macro periods" // "When the VCSEL period for the pre or final range is changed, // the corresponding timeout must be read from the device using // the current VCSEL period, then the new VCSEL period can be // applied. The timeout then must be written back to the device // using the new VCSEL period. // // For the MSRC timeout, the same applies - this timeout being // dependant on the pre-range vcsel period." if (type == VcselPeriodPreRange) { // "Set phase check limits" switch (period_pclks) { case 12: writeReg8(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x18); break; case 14: writeReg8(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x30); break; case 16: writeReg8(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x40); break; case 18: writeReg8(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x50); break; default: // invalid period return false; } writeReg8(PRE_RANGE_CONFIG_VALID_PHASE_LOW, 0x08); // apply new VCSEL period writeReg8(PRE_RANGE_CONFIG_VCSEL_PERIOD, vcsel_period_reg); // update timeouts // set_sequence_step_timeout() begin // (SequenceStepId == VL53L0X_SEQUENCESTEP_PRE_RANGE) uint16_t new_pre_range_timeout_mclks = timeoutMicrosecondsToMclks(timeouts.pre_range_us, period_pclks); writeReg16(PRE_RANGE_CONFIG_TIMEOUT_MACROP_HI, encodeTimeout(new_pre_range_timeout_mclks)); // set_sequence_step_timeout() end // set_sequence_step_timeout() begin // (SequenceStepId == VL53L0X_SEQUENCESTEP_MSRC) uint16_t new_msrc_timeout_mclks = timeoutMicrosecondsToMclks(timeouts.msrc_dss_tcc_us, period_pclks); writeReg8(MSRC_CONFIG_TIMEOUT_MACROP, (new_msrc_timeout_mclks > 256) ? 255 : (new_msrc_timeout_mclks - 1)); // set_sequence_step_timeout() end } else if (type == VcselPeriodFinalRange) { switch (period_pclks) { case 8: writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x10); writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08); writeReg8(GLOBAL_CONFIG_VCSEL_WIDTH, 0x02); writeReg8(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x0C); writeReg8(0xFF, 0x01); writeReg8(ALGO_PHASECAL_LIM, 0x30); writeReg8(0xFF, 0x00); break; case 10: writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x28); writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08); writeReg8(GLOBAL_CONFIG_VCSEL_WIDTH, 0x03); writeReg8(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x09); writeReg8(0xFF, 0x01); writeReg8(ALGO_PHASECAL_LIM, 0x20); writeReg8(0xFF, 0x00); break; case 12: writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x38); writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08); writeReg8(GLOBAL_CONFIG_VCSEL_WIDTH, 0x03); writeReg8(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x08); writeReg8(0xFF, 0x01); writeReg8(ALGO_PHASECAL_LIM, 0x20); writeReg8(0xFF, 0x00); break; case 14: writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x48); writeReg8(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08); writeReg8(GLOBAL_CONFIG_VCSEL_WIDTH, 0x03); writeReg8(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x07); writeReg8(0xFF, 0x01); writeReg8(ALGO_PHASECAL_LIM, 0x20); writeReg8(0xFF, 0x00); break; default: // invalid period return false; } // apply new VCSEL period writeReg8(FINAL_RANGE_CONFIG_VCSEL_PERIOD, vcsel_period_reg); // update timeouts // set_sequence_step_timeout() begin // (SequenceStepId == VL53L0X_SEQUENCESTEP_FINAL_RANGE) // "For the final range timeout, the pre-range timeout // must be added. To do this both final and pre-range // timeouts must be expressed in macro periods MClks // because they have different vcsel periods." uint16_t new_final_range_timeout_mclks = timeoutMicrosecondsToMclks(timeouts.final_range_us, period_pclks); if (enables.pre_range) { new_final_range_timeout_mclks += timeouts.pre_range_mclks; } writeReg16(FINAL_RANGE_CONFIG_TIMEOUT_MACROP_HI, encodeTimeout(new_final_range_timeout_mclks)); // set_sequence_step_timeout end } else { // invalid type return false; } // "Finally, the timing budget must be re-applied" setMeasurementTimingBudget(measurement_timing_budget_us); // "Perform the phase calibration. This is needed after changing on vcsel period." // VL53L0X_perform_phase_calibration() begin uint8_t sequence_config = readReg8(SYSTEM_SEQUENCE_CONFIG); writeReg8(SYSTEM_SEQUENCE_CONFIG, 0x02); performSingleRefCalibration(0x0); writeReg8(SYSTEM_SEQUENCE_CONFIG, sequence_config); // VL53L0X_perform_phase_calibration() end return true; } private: uint8_t readReg8(const uint8_t reg) { beginReadRegister(reg); uint8_t res = 0; i2c::readBytes(&res, 1); i2c::stop(); return res; } uint16_t readReg16(const uint8_t reg) { beginReadRegister(reg); uint8_t buf[2]; i2c::readBytes(buf, 2); i2c::stop(); uint16_t res = buf[0]; res <<= 8; res |= buf[1]; return res; } void readRegN(const uint8_t reg, uint8_t* dst, const size_t len) { beginReadRegister(reg); i2c::readBytes(dst, len); i2c::stop(); } /** internal helper method. begin writing to the device */ void beginWriteRegister(const uint8_t reg) { bool ok; // select device for writing ok = i2c::startWrite(ADDR); if (!ok) {debugMod(NAME, "failed startWrite()");} // select register to write to ok = i2c::writeByteAndCheck(reg); if (!ok) {debugMod1(NAME, "failed to select register %d", reg);} } /** internal helper method. begin reading from the device */ void beginReadRegister(const uint8_t reg) { bool ok; // select device for writing ok = i2c::startWrite(ADDR); if (!ok) {debugMod(NAME, "failed startWrite()");} // select register to read from ok = i2c::writeByteAndCheck(reg); if (!ok) {debugMod1(NAME, "failed to select register %d", reg);} i2c::stop(); // re-address in read mode ok = i2c::startRead(ADDR); if (!ok) {debugMod(NAME, "failed startRead()");} } void writeReg8(const uint8_t reg, const uint8_t val) { beginWriteRegister(reg); bool ok = i2c::writeByteAndCheck(val); if (!ok) {debugMod(NAME, "failed to write byte");} i2c::stop(); } void writeReg16(const uint8_t reg, const uint16_t val) { beginWriteRegister(reg); bool ok; ok = i2c::writeByteAndCheck(val >> 8); if (!ok) {debugMod(NAME, "failed to write 1st byte");} ok = i2c::writeByteAndCheck(val >> 0); if (!ok) {debugMod(NAME, "failed to write 2nd byte");} i2c::stop(); } void writeReg32(const uint8_t reg, const uint32_t val) { beginWriteRegister(reg); bool ok; ok = i2c::writeByteAndCheck(val >> 24); if (!ok) {debugMod(NAME, "failed to write 1st byte");} ok = i2c::writeByteAndCheck(val >> 16); if (!ok) {debugMod(NAME, "failed to write 2nd byte");} ok = i2c::writeByteAndCheck(val >> 8); if (!ok) {debugMod(NAME, "failed to write 3rd byte");} ok = i2c::writeByteAndCheck(val >> 0); if (!ok) {debugMod(NAME, "failed to write 4th byte");} i2c::stop(); } void writeRegN(const uint8_t reg, const uint8_t* data, const size_t len) { beginWriteRegister(reg); for (size_t i = 0; i < len; ++i) { bool ok = i2c::writeByteAndCheck(data[i]); if (!ok) {debugMod(NAME, "failed to write byte"); break;} } i2c::stop(); } public: void initOnce() { if (inited) {return;} init(); inited = true; } bool isPresent() { return i2c::query(ADDR); } /** check whether the sensor responds with some known values */ bool check() { const uint8_t v1 = readReg8(0xC0); // should be 0xEE const uint8_t v2 = readReg8(0xC1); // should be 0xAA const uint8_t v3 = readReg8(0xC2); // should be 0x10 const bool ok = (v1 == 0xEE) && (v2 == 0xAA) && (v3 == 0x10); os_printf("res. %d %d %d\n\n", v1, v2, v3); return ok; } // Start continuous ranging measurements. If period_ms (optional) is 0 or not // given, continuous back-to-back mode is used (the sensor takes measurements as // often as possible); otherwise, continuous timed mode is used, with the given // inter-measurement period in milliseconds determining how often the sensor // takes a measurement. // based on VL53L0X_StartMeasurement() void startContinuous(uint32_t period_ms) { writeReg8(0x80, 0x01); writeReg8(0xFF, 0x01); writeReg8(0x00, 0x00); writeReg8(0x91, stop_variable); writeReg8(0x00, 0x01); writeReg8(0xFF, 0x00); writeReg8(0x80, 0x00); if (period_ms != 0) { // continuous timed mode // VL53L0X_SetInterMeasurementPeriodMilliSeconds() begin uint16_t osc_calibrate_val = readReg16(OSC_CALIBRATE_VAL); if (osc_calibrate_val != 0) { period_ms *= osc_calibrate_val; } writeReg32(SYSTEM_INTERMEASUREMENT_PERIOD, period_ms); // VL53L0X_SetInterMeasurementPeriodMilliSeconds() end writeReg8(SYSRANGE_START, 0x04); // VL53L0X_REG_SYSRANGE_MODE_TIMED } else { // continuous back-to-back mode writeReg8(SYSRANGE_START, 0x02); // VL53L0X_REG_SYSRANGE_MODE_BACKTOBACK } } // Stop continuous measurements // based on VL53L0X_StopMeasurement() void stopContinuous(void) { writeReg8(SYSRANGE_START, 0x01); // VL53L0X_REG_SYSRANGE_MODE_SINGLESHOT writeReg8(0xFF, 0x01); writeReg8(0x00, 0x00); writeReg8(0x91, 0x00); writeReg8(0x00, 0x01); writeReg8(0xFF, 0x00); } // Returns a range reading in millimeters when continuous mode is active // (readRangeSingleMillimeters() also calls this function after starting a // single-shot range measurement) uint16_t readRangeContinuousMillimeters(void) { int cnt = 0; while ((readReg8(RESULT_INTERRUPT_STATUS) & 0x07) == 0) { if (++cnt > 100) { debugMod(NAME, "measurement timeout!"); return 65535; } } // assumptions: Linearity Corrective Gain is 1000 (default); // fractional ranging is not enabled uint16_t range = readReg16(RESULT_RANGE_STATUS + 10); writeReg8(SYSTEM_INTERRUPT_CLEAR, 0x01); return range; } }; #endif // VL53L0X