Deepana Ishtaweera
tof library
Diff: VL53L0X.cpp
- Revision:
- 0:1c8c01640f54
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/VL53L0X.cpp Tue Oct 01 12:33:27 2019 +0000
@@ -0,0 +1,1077 @@
+// Most of the functionality of this library is based on the VL53L0X API
+// provided by ST (STSW-IMG005), and some of the explanatory comments are quoted
+// or paraphrased from the API source code, API user manual (UM2039), and the
+// VL53L0X datasheet.
+
+#include <memory>
+#include <VL53L0X.h>
+
+// Defines /////////////////////////////////////////////////////////////////////
+
+// The Arduino two-wire interface uses a 7-bit number for the address,
+// and sets the last bit correctly based on reads and writes
+#define ADDRESS_DEFAULT (0b0101001 << 1)
+
+// Record the current time to check an upcoming timeout against
+#define startTimeout() (timeout_start_ms = millis())
+
+// Check if timeout is enabled (set to nonzero value) and has expired
+#define checkTimeoutExpired() (io_timeout > 0 && ((uint16_t)millis() - timeout_start_ms) > io_timeout)
+
+// 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)
+
+// 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)
+
+// Transmission status (https://www.arduino.cc/en/Reference/WireEndTransmission)
+#define ERR_OK 0
+#define ERR_NACK_ADDR 2 // received NACK on transmit of address
+#define ERR_NACK_DATA 3 // received NACK on transmit of data
+#define ERR_OTHER 4
+
+#define millis() timer->read_ms()
+
+// Constructors ////////////////////////////////////////////////////////////////
+
+VL53L0X::VL53L0X(I2C* i2c, Timer* timer)
+ : address(ADDRESS_DEFAULT)
+ , io_timeout(0) // no timeout
+ , did_timeout(false)
+ , i2c(i2c)
+ , timer(timer)
+{
+}
+
+// Public Methods //////////////////////////////////////////////////////////////
+
+void VL53L0X::setAddress(uint8_t new_addr)
+{
+ writeReg(I2C_SLAVE_DEVICE_ADDRESS, new_addr & 0x7F);
+ address = new_addr << 1;
+}
+
+// Initialize sensor using sequence based on VL53L0X_DataInit(),
+// VL53L0X_StaticInit(), and VL53L0X_PerformRefCalibration().
+// This function does not perform reference SPAD calibration
+// (VL53L0X_PerformRefSpadManagement()), since the API user manual says that it
+// is performed by ST on the bare modules; it seems like that should work well
+// enough unless a cover glass is added.
+// If io_2v8 (optional) is true or not given, the sensor is configured for 2V8
+// mode.
+bool VL53L0X::init(bool io_2v8)
+{
+ // VL53L0X_DataInit() begin
+
+ // sensor uses 1V8 mode for I/O by default; switch to 2V8 mode if necessary
+ if (io_2v8)
+ {
+ writeReg(VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV,
+ readReg(VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV) | 0x01); // set bit 0
+ }
+
+ // "Set I2C standard mode"
+ writeReg(0x88, 0x00);
+
+ writeReg(0x80, 0x01);
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x00);
+ stop_variable = readReg(0x91);
+ writeReg(0x00, 0x01);
+ writeReg(0xFF, 0x00);
+ writeReg(0x80, 0x00);
+
+ // disable SIGNAL_RATE_MSRC (bit 1) and SIGNAL_RATE_PRE_RANGE (bit 4) limit checks
+ writeReg(MSRC_CONFIG_CONTROL, readReg(MSRC_CONFIG_CONTROL) | 0x12);
+
+ // set final range signal rate limit to 0.25 MCPS (million counts per second)
+ setSignalRateLimit(0.25);
+
+ writeReg(SYSTEM_SEQUENCE_CONFIG, 0xFF);
+
+ // VL53L0X_DataInit() end
+
+ // VL53L0X_StaticInit() begin
+
+ uint8_t spad_count;
+ bool spad_type_is_aperture;
+ if (!getSpadInfo(&spad_count, &spad_type_is_aperture)) { 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];
+ readMulti(GLOBAL_CONFIG_SPAD_ENABLES_REF_0, ref_spad_map, 6);
+
+ // -- VL53L0X_set_reference_spads() begin (assume NVM values are valid)
+
+ writeReg(0xFF, 0x01);
+ writeReg(DYNAMIC_SPAD_REF_EN_START_OFFSET, 0x00);
+ writeReg(DYNAMIC_SPAD_NUM_REQUESTED_REF_SPAD, 0x2C);
+ writeReg(0xFF, 0x00);
+ writeReg(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++;
+ }
+ }
+
+ writeMulti(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
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x00);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x09, 0x00);
+ writeReg(0x10, 0x00);
+ writeReg(0x11, 0x00);
+
+ writeReg(0x24, 0x01);
+ writeReg(0x25, 0xFF);
+ writeReg(0x75, 0x00);
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x4E, 0x2C);
+ writeReg(0x48, 0x00);
+ writeReg(0x30, 0x20);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x30, 0x09);
+ writeReg(0x54, 0x00);
+ writeReg(0x31, 0x04);
+ writeReg(0x32, 0x03);
+ writeReg(0x40, 0x83);
+ writeReg(0x46, 0x25);
+ writeReg(0x60, 0x00);
+ writeReg(0x27, 0x00);
+ writeReg(0x50, 0x06);
+ writeReg(0x51, 0x00);
+ writeReg(0x52, 0x96);
+ writeReg(0x56, 0x08);
+ writeReg(0x57, 0x30);
+ writeReg(0x61, 0x00);
+ writeReg(0x62, 0x00);
+ writeReg(0x64, 0x00);
+ writeReg(0x65, 0x00);
+ writeReg(0x66, 0xA0);
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x22, 0x32);
+ writeReg(0x47, 0x14);
+ writeReg(0x49, 0xFF);
+ writeReg(0x4A, 0x00);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x7A, 0x0A);
+ writeReg(0x7B, 0x00);
+ writeReg(0x78, 0x21);
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x23, 0x34);
+ writeReg(0x42, 0x00);
+ writeReg(0x44, 0xFF);
+ writeReg(0x45, 0x26);
+ writeReg(0x46, 0x05);
+ writeReg(0x40, 0x40);
+ writeReg(0x0E, 0x06);
+ writeReg(0x20, 0x1A);
+ writeReg(0x43, 0x40);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x34, 0x03);
+ writeReg(0x35, 0x44);
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x31, 0x04);
+ writeReg(0x4B, 0x09);
+ writeReg(0x4C, 0x05);
+ writeReg(0x4D, 0x04);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x44, 0x00);
+ writeReg(0x45, 0x20);
+ writeReg(0x47, 0x08);
+ writeReg(0x48, 0x28);
+ writeReg(0x67, 0x00);
+ writeReg(0x70, 0x04);
+ writeReg(0x71, 0x01);
+ writeReg(0x72, 0xFE);
+ writeReg(0x76, 0x00);
+ writeReg(0x77, 0x00);
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x0D, 0x01);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x80, 0x01);
+ writeReg(0x01, 0xF8);
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x8E, 0x01);
+ writeReg(0x00, 0x01);
+ writeReg(0xFF, 0x00);
+ writeReg(0x80, 0x00);
+
+ // -- VL53L0X_load_tuning_settings() end
+
+ // "Set interrupt config to new sample ready"
+ // -- VL53L0X_SetGpioConfig() begin
+
+ writeReg(SYSTEM_INTERRUPT_CONFIG_GPIO, 0x04);
+ writeReg(GPIO_HV_MUX_ACTIVE_HIGH, readReg(GPIO_HV_MUX_ACTIVE_HIGH) & ~0x10); // active low
+ writeReg(SYSTEM_INTERRUPT_CLEAR, 0x01);
+
+ // -- VL53L0X_SetGpioConfig() end
+
+ measurement_timing_budget_us = getMeasurementTimingBudget();
+
+ // "Disable MSRC and TCC by default"
+ // MSRC = Minimum Signal Rate Check
+ // TCC = Target CentreCheck
+ // -- VL53L0X_SetSequenceStepEnable() begin
+
+ writeReg(SYSTEM_SEQUENCE_CONFIG, 0xE8);
+
+ // -- VL53L0X_SetSequenceStepEnable() end
+
+ // "Recalculate timing budget"
+ setMeasurementTimingBudget(measurement_timing_budget_us);
+
+ // VL53L0X_StaticInit() end
+
+ // VL53L0X_PerformRefCalibration() begin (VL53L0X_perform_ref_calibration())
+
+ // -- VL53L0X_perform_vhv_calibration() begin
+
+ writeReg(SYSTEM_SEQUENCE_CONFIG, 0x01);
+ if (!performSingleRefCalibration(0x40)) { return false; }
+
+ // -- VL53L0X_perform_vhv_calibration() end
+
+ // -- VL53L0X_perform_phase_calibration() begin
+
+ writeReg(SYSTEM_SEQUENCE_CONFIG, 0x02);
+ if (!performSingleRefCalibration(0x00)) { return false; }
+
+ // -- VL53L0X_perform_phase_calibration() end
+
+ // "restore the previous Sequence Config"
+ writeReg(SYSTEM_SEQUENCE_CONFIG, 0xE8);
+
+ // VL53L0X_PerformRefCalibration() end
+
+ return true;
+}
+
+// Write an 8-bit register
+void VL53L0X::writeReg(uint8_t reg, uint8_t value)
+{
+ char data[] = {
+ reg,
+ value
+ };
+ if (i2c->write(address, data, 2)) {
+ last_status = ERR_OTHER;
+ } else {
+ last_status = ERR_OK;
+ }
+}
+
+// Write a 16-bit register
+void VL53L0X::writeReg16Bit(uint8_t reg, uint16_t value)
+{
+ char data[] = {
+ reg,
+ static_cast<char>((value >> 8) & 0xFF), // value high byte
+ static_cast<char>(value & 0xFF) // value low byte
+ };
+ if (i2c->write(address, data, 3)) {
+ last_status = ERR_OTHER;
+ } else {
+ last_status = ERR_OK;
+ }
+}
+
+// Write a 32-bit register
+void VL53L0X::writeReg32Bit(uint8_t reg, uint32_t value)
+{
+ char data[] = {
+ reg,
+ static_cast<char>((value >> 24) & 0xFF), // value highest byte
+ static_cast<char>((value >> 16) & 0xFF),
+ static_cast<char>((value >> 8) & 0xFF),
+ static_cast<char>(value & 0xFF) // value lowest byte
+ };
+ if (i2c->write(address, data, 5)) {
+ last_status = ERR_OTHER;
+ } else {
+ last_status = ERR_OK;
+ }
+}
+
+// Read an 8-bit register
+uint8_t VL53L0X::readReg(uint8_t reg)
+{
+ uint8_t value;
+
+ if (i2c->write(address, reinterpret_cast<char *>(®), 1)) {
+ last_status = ERR_NACK_ADDR;
+ return 0;
+ }
+ if (i2c->read(address, reinterpret_cast<char *>(&value), 1)) {
+ last_status = ERR_NACK_DATA;
+ return 0;
+ }
+ last_status = ERR_OK;
+
+ return value;
+}
+
+// Read a 16-bit register
+uint16_t VL53L0X::readReg16Bit(uint8_t reg)
+{
+ uint16_t value;
+ uint8_t data[2];
+
+ if (i2c->write(address, reinterpret_cast<char *>(®), 1)) {
+ last_status = ERR_NACK_ADDR;
+ return 0;
+ }
+ if (i2c->read(address, reinterpret_cast<char *>(data), 2)) {
+ last_status = ERR_NACK_DATA;
+ return 0;
+ }
+ last_status = ERR_OK;
+
+ value = static_cast<uint16_t>(data[0] << 8); // value high byte
+ value |= data[1]; // value low byte
+
+ return value;
+}
+
+// Read a 32-bit register
+uint32_t VL53L0X::readReg32Bit(uint8_t reg)
+{
+ uint32_t value;
+ uint8_t data[4];
+
+ if (i2c->write(address, reinterpret_cast<char *>(®), 1)) {
+ last_status = ERR_NACK_ADDR;
+ return 0;
+ }
+ if (i2c->read(address, reinterpret_cast<char *>(data), 4)) {
+ last_status = ERR_NACK_DATA;
+ return 0;
+ }
+ last_status = ERR_OK;
+
+ value = static_cast<uint32_t>(data[0] << 24); // value highest byte
+ value |= static_cast<uint32_t>(data[1] << 16);
+ value |= static_cast<uint32_t>(data[2] << 8);
+ value |= data[3]; // value lowest byte
+
+ return value;
+}
+
+// Write an arbitrary number of bytes from the given array to the sensor,
+// starting at the given register
+void VL53L0X::writeMulti(uint8_t reg, uint8_t const * src, uint8_t count)
+{
+ if (i2c->write(address, reinterpret_cast<char *>(®), 1, true)) {
+ last_status = ERR_NACK_ADDR;
+ return;
+ }
+
+ if (i2c->write(address, const_cast<char *>(
+ reinterpret_cast<const char *>(src)), count)) {
+ last_status = ERR_NACK_DATA;
+ return;
+ }
+ last_status = ERR_OK;
+}
+
+// Read an arbitrary number of bytes from the sensor, starting at the given
+// register, into the given array
+void VL53L0X::readMulti(uint8_t reg, uint8_t * dst, uint8_t count)
+{
+ if (i2c->write(address, reinterpret_cast<char *>(®), 1)) {
+ last_status = ERR_NACK_ADDR;
+ return;
+ }
+ if (i2c->read(address, reinterpret_cast<char *>(dst), count)) {
+ last_status = ERR_NACK_DATA;
+ return;
+ }
+ last_status = ERR_OK;
+}
+
+// Set the return signal rate limit check value in units of MCPS (mega counts
+// per second). "This represents the amplitude of the signal reflected from the
+// target and detected by the device"; setting this limit presumably determines
+// the minimum measurement necessary for the sensor to report a valid reading.
+// Setting a lower limit increases the potential range of the sensor but also
+// seems to increase the likelihood of getting an inaccurate reading because of
+// unwanted reflections from objects other than the intended target.
+// Defaults to 0.25 MCPS as initialized by the ST API and this library.
+bool VL53L0X::setSignalRateLimit(float limit_Mcps)
+{
+ if (limit_Mcps < 0 || limit_Mcps > 511.99) { return false; }
+
+ // Q9.7 fixed point format (9 integer bits, 7 fractional bits)
+ writeReg16Bit(FINAL_RANGE_CONFIG_MIN_COUNT_RATE_RTN_LIMIT, limit_Mcps * (1 << 7));
+ return true;
+}
+
+// Get the return signal rate limit check value in MCPS
+float VL53L0X::getSignalRateLimit(void)
+{
+ return (float)readReg16Bit(FINAL_RANGE_CONFIG_MIN_COUNT_RATE_RTN_LIMIT) / (1 << 7);
+}
+
+// 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 VL53L0X::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;
+ }
+
+ writeReg16Bit(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 the measurement timing budget in microseconds
+// based on VL53L0X_get_measurement_timing_budget_micro_seconds()
+// in us
+uint32_t VL53L0X::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 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 VL53L0X::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:
+ writeReg(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x18);
+ break;
+
+ case 14:
+ writeReg(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x30);
+ break;
+
+ case 16:
+ writeReg(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x40);
+ break;
+
+ case 18:
+ writeReg(PRE_RANGE_CONFIG_VALID_PHASE_HIGH, 0x50);
+ break;
+
+ default:
+ // invalid period
+ return false;
+ }
+ writeReg(PRE_RANGE_CONFIG_VALID_PHASE_LOW, 0x08);
+
+ // apply new VCSEL period
+ writeReg(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);
+
+ writeReg16Bit(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);
+
+ writeReg(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:
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x10);
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08);
+ writeReg(GLOBAL_CONFIG_VCSEL_WIDTH, 0x02);
+ writeReg(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x0C);
+ writeReg(0xFF, 0x01);
+ writeReg(ALGO_PHASECAL_LIM, 0x30);
+ writeReg(0xFF, 0x00);
+ break;
+
+ case 10:
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x28);
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08);
+ writeReg(GLOBAL_CONFIG_VCSEL_WIDTH, 0x03);
+ writeReg(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x09);
+ writeReg(0xFF, 0x01);
+ writeReg(ALGO_PHASECAL_LIM, 0x20);
+ writeReg(0xFF, 0x00);
+ break;
+
+ case 12:
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x38);
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08);
+ writeReg(GLOBAL_CONFIG_VCSEL_WIDTH, 0x03);
+ writeReg(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x08);
+ writeReg(0xFF, 0x01);
+ writeReg(ALGO_PHASECAL_LIM, 0x20);
+ writeReg(0xFF, 0x00);
+ break;
+
+ case 14:
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_HIGH, 0x48);
+ writeReg(FINAL_RANGE_CONFIG_VALID_PHASE_LOW, 0x08);
+ writeReg(GLOBAL_CONFIG_VCSEL_WIDTH, 0x03);
+ writeReg(ALGO_PHASECAL_CONFIG_TIMEOUT, 0x07);
+ writeReg(0xFF, 0x01);
+ writeReg(ALGO_PHASECAL_LIM, 0x20);
+ writeReg(0xFF, 0x00);
+ break;
+
+ default:
+ // invalid period
+ return false;
+ }
+
+ // apply new VCSEL period
+ writeReg(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;
+ }
+
+ writeReg16Bit(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 = readReg(SYSTEM_SEQUENCE_CONFIG);
+ writeReg(SYSTEM_SEQUENCE_CONFIG, 0x02);
+ performSingleRefCalibration(0x0);
+ writeReg(SYSTEM_SEQUENCE_CONFIG, sequence_config);
+
+ // VL53L0X_perform_phase_calibration() end
+
+ return true;
+}
+
+// Get the VCSEL pulse period in PCLKs for the given period type.
+// based on VL53L0X_get_vcsel_pulse_period()
+uint8_t VL53L0X::getVcselPulsePeriod(vcselPeriodType type)
+{
+ if (type == VcselPeriodPreRange)
+ {
+ return decodeVcselPeriod(readReg(PRE_RANGE_CONFIG_VCSEL_PERIOD));
+ }
+ else if (type == VcselPeriodFinalRange)
+ {
+ return decodeVcselPeriod(readReg(FINAL_RANGE_CONFIG_VCSEL_PERIOD));
+ }
+ else { return 255; }
+}
+
+// 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 VL53L0X::startContinuous(uint32_t period_ms)
+{
+ writeReg(0x80, 0x01);
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x00);
+ writeReg(0x91, stop_variable);
+ writeReg(0x00, 0x01);
+ writeReg(0xFF, 0x00);
+ writeReg(0x80, 0x00);
+
+ if (period_ms != 0)
+ {
+ // continuous timed mode
+
+ // VL53L0X_SetInterMeasurementPeriodMilliSeconds() begin
+
+ uint16_t osc_calibrate_val = readReg16Bit(OSC_CALIBRATE_VAL);
+
+ if (osc_calibrate_val != 0)
+ {
+ period_ms *= osc_calibrate_val;
+ }
+
+ writeReg32Bit(SYSTEM_INTERMEASUREMENT_PERIOD, period_ms);
+
+ // VL53L0X_SetInterMeasurementPeriodMilliSeconds() end
+
+ writeReg(SYSRANGE_START, 0x04); // VL53L0X_REG_SYSRANGE_MODE_TIMED
+ }
+ else
+ {
+ // continuous back-to-back mode
+ writeReg(SYSRANGE_START, 0x02); // VL53L0X_REG_SYSRANGE_MODE_BACKTOBACK
+ }
+}
+
+// Stop continuous measurements
+// based on VL53L0X_StopMeasurement()
+void VL53L0X::stopContinuous(void)
+{
+ writeReg(SYSRANGE_START, 0x01); // VL53L0X_REG_SYSRANGE_MODE_SINGLESHOT
+
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x00);
+ writeReg(0x91, 0x00);
+ writeReg(0x00, 0x01);
+ writeReg(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 VL53L0X::readRangeContinuousMillimeters(void)
+{
+ startTimeout();
+ while ((readReg(RESULT_INTERRUPT_STATUS) & 0x07) == 0)
+ {
+ if (checkTimeoutExpired())
+ {
+ did_timeout = true;
+ return 65535;
+ }
+ }
+
+ // assumptions: Linearity Corrective Gain is 1000 (default);
+ // fractional ranging is not enabled
+ uint16_t range = readReg16Bit(RESULT_RANGE_STATUS + 10);
+
+ writeReg(SYSTEM_INTERRUPT_CLEAR, 0x01);
+
+ return range;
+}
+
+// Performs a single-shot range measurement and returns the reading in
+// millimeters
+// based on VL53L0X_PerformSingleRangingMeasurement()
+uint16_t VL53L0X::readRangeSingleMillimeters(void)
+{
+ writeReg(0x80, 0x01);
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x00);
+ writeReg(0x91, stop_variable);
+ writeReg(0x00, 0x01);
+ writeReg(0xFF, 0x00);
+ writeReg(0x80, 0x00);
+
+ writeReg(SYSRANGE_START, 0x01);
+
+ // "Wait until start bit has been cleared"
+ startTimeout();
+ while (readReg(SYSRANGE_START) & 0x01)
+ {
+ if (checkTimeoutExpired())
+ {
+ did_timeout = true;
+ return 65535;
+ }
+ }
+
+ return readRangeContinuousMillimeters();
+}
+
+// Did a timeout occur in one of the read functions since the last call to
+// timeoutOccurred()?
+bool VL53L0X::timeoutOccurred()
+{
+ bool tmp = did_timeout;
+ did_timeout = false;
+ return tmp;
+}
+
+// Private Methods /////////////////////////////////////////////////////////////
+
+// 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 VL53L0X::getSpadInfo(uint8_t * count, bool * type_is_aperture)
+{
+ uint8_t tmp;
+
+ writeReg(0x80, 0x01);
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x00);
+
+ writeReg(0xFF, 0x06);
+ writeReg(0x83, readReg(0x83) | 0x04);
+ writeReg(0xFF, 0x07);
+ writeReg(0x81, 0x01);
+
+ writeReg(0x80, 0x01);
+
+ writeReg(0x94, 0x6b);
+ writeReg(0x83, 0x00);
+ startTimeout();
+ while (readReg(0x83) == 0x00)
+ {
+ if (checkTimeoutExpired()) { return false; }
+ }
+ writeReg(0x83, 0x01);
+ tmp = readReg(0x92);
+
+ *count = tmp & 0x7f;
+ *type_is_aperture = (tmp >> 7) & 0x01;
+
+ writeReg(0x81, 0x00);
+ writeReg(0xFF, 0x06);
+ writeReg(0x83, readReg( 0x83 & ~0x04));
+ writeReg(0xFF, 0x01);
+ writeReg(0x00, 0x01);
+
+ writeReg(0xFF, 0x00);
+ writeReg(0x80, 0x00);
+
+ return true;
+}
+
+// Get sequence step enables
+// based on VL53L0X_GetSequenceStepEnables()
+void VL53L0X::getSequenceStepEnables(SequenceStepEnables * enables)
+{
+ uint8_t sequence_config = readReg(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 VL53L0X::getSequenceStepTimeouts(SequenceStepEnables const * enables, SequenceStepTimeouts * timeouts)
+{
+ timeouts->pre_range_vcsel_period_pclks = getVcselPulsePeriod(VcselPeriodPreRange);
+
+ timeouts->msrc_dss_tcc_mclks = readReg(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(readReg16Bit(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(readReg16Bit(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);
+}
+
+// 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 VL53L0X::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 VL53L0X::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; }
+}
+
+// Convert sequence step timeout from MCLKs to microseconds with given VCSEL period in PCLKs
+// based on VL53L0X_calc_timeout_us()
+uint32_t VL53L0X::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 VL53L0X::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);
+}
+
+
+// based on VL53L0X_perform_single_ref_calibration()
+bool VL53L0X::performSingleRefCalibration(uint8_t vhv_init_byte)
+{
+ writeReg(SYSRANGE_START, 0x01 | vhv_init_byte); // VL53L0X_REG_SYSRANGE_MODE_START_STOP
+
+ startTimeout();
+ while ((readReg(RESULT_INTERRUPT_STATUS) & 0x07) == 0)
+ {
+ if (checkTimeoutExpired()) { return false; }
+ }
+
+ writeReg(SYSTEM_INTERRUPT_CLEAR, 0x01);
+
+ writeReg(SYSRANGE_START, 0x00);
+
+ return true;
+}