ardupilot/libraries/AP_RangeFinder/AP_RangeFinder_VL53L0X.cpp

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/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
driver for ST VL53L0X lidar
Many thanks to Pololu, https://github.com/pololu/vl53l0x-arduino and
the ST example code
*/
#include "AP_RangeFinder_VL53L0X.h"
#if AP_RANGEFINDER_VL53L0X_ENABLED
#include <utility>
#include <AP_HAL/AP_HAL.h>
#include <AP_HAL/utility/sparse-endian.h>
#include <stdio.h>
extern const AP_HAL::HAL& hal;
enum regAddr
{
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,
};
// tuning register settings
const AP_RangeFinder_VL53L0X::RegData AP_RangeFinder_VL53L0X::tuning_data[] =
{
{ 0xFF, 0x01 },
{ 0x00, 0x00 },
{ 0xFF, 0x00 },
{ 0x09, 0x00 },
{ 0x10, 0x00 },
{ 0x11, 0x00 },
{ 0x24, 0x01 },
{ 0x25, 0xFF },
{ 0x75, 0x00 },
{ 0xFF, 0x01 },
{ 0x4E, 0x2C },
{ 0x48, 0x00 },
{ 0x30, 0x20 },
{ 0xFF, 0x00 },
{ 0x30, 0x09 },
{ 0x54, 0x00 },
{ 0x31, 0x04 },
{ 0x32, 0x03 },
{ 0x40, 0x83 },
{ 0x46, 0x25 },
{ 0x60, 0x00 },
{ 0x27, 0x00 },
{ 0x50, 0x06 },
{ 0x51, 0x00 },
{ 0x52, 0x96 },
{ 0x56, 0x08 },
{ 0x57, 0x30 },
{ 0x61, 0x00 },
{ 0x62, 0x00 },
{ 0x64, 0x00 },
{ 0x65, 0x00 },
{ 0x66, 0xA0 },
{ 0xFF, 0x01 },
{ 0x22, 0x32 },
{ 0x47, 0x14 },
{ 0x49, 0xFF },
{ 0x4A, 0x00 },
{ 0xFF, 0x00 },
{ 0x7A, 0x0A },
{ 0x7B, 0x00 },
{ 0x78, 0x21 },
{ 0xFF, 0x01 },
{ 0x23, 0x34 },
{ 0x42, 0x00 },
{ 0x44, 0xFF },
{ 0x45, 0x26 },
{ 0x46, 0x05 },
{ 0x40, 0x40 },
{ 0x0E, 0x06 },
{ 0x20, 0x1A },
{ 0x43, 0x40 },
{ 0xFF, 0x00 },
{ 0x34, 0x03 },
{ 0x35, 0x44 },
{ 0xFF, 0x01 },
{ 0x31, 0x04 },
{ 0x4B, 0x09 },
{ 0x4C, 0x05 },
{ 0x4D, 0x04 },
{ 0xFF, 0x00 },
{ 0x44, 0x00 },
{ 0x45, 0x20 },
{ 0x47, 0x08 },
{ 0x48, 0x28 },
{ 0x67, 0x00 },
{ 0x70, 0x04 },
{ 0x71, 0x01 },
{ 0x72, 0xFE },
{ 0x76, 0x00 },
{ 0x77, 0x00 },
{ 0xFF, 0x01 },
{ 0x0D, 0x01 },
{ 0xFF, 0x00 },
{ 0x80, 0x01 },
{ 0x01, 0xF8 },
{ 0xFF, 0x01 },
{ 0x8E, 0x01 },
{ 0x00, 0x01 },
{ 0xFF, 0x00 },
{ 0x80, 0x00 },
};
AP_RangeFinder_VL53L0X::AP_RangeFinder_VL53L0X(RangeFinder::RangeFinder_State &_state, AP_RangeFinder_Params &_params, AP_HAL::OwnPtr<AP_HAL::I2CDevice> _dev)
: AP_RangeFinder_Backend(_state, _params)
, dev(std::move(_dev)) {}
/*
detect if a VL53L0X rangefinder is connected. We'll detect by
trying to take a reading on I2C. If we get a result the sensor is
there.
*/
AP_RangeFinder_Backend *AP_RangeFinder_VL53L0X::detect(RangeFinder::RangeFinder_State &_state, AP_RangeFinder_Params &_params, AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev)
{
if (!dev) {
return nullptr;
}
AP_RangeFinder_VL53L0X *sensor
= new AP_RangeFinder_VL53L0X(_state, _params, std::move(dev));
if (!sensor) {
delete sensor;
return nullptr;
}
sensor->dev->get_semaphore()->take_blocking();
if (!sensor->check_id() || !sensor->init()) {
sensor->dev->get_semaphore()->give();
delete sensor;
return nullptr;
}
sensor->dev->get_semaphore()->give();
return sensor;
}
// check sensor ID registers
bool AP_RangeFinder_VL53L0X::check_id(void)
{
uint8_t v1, v2;
if (!dev->read_registers(0xC0, &v1, 1) ||
!dev->read_registers(0xC1, &v2, 1) ||
v1 != 0xEE ||
v2 != 0xAA) {
return false;
}
printf("Detected VL53L0X on bus 0x%x\n", dev->get_bus_id());
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 AP_RangeFinder_VL53L0X::get_SPAD_info(uint8_t * count, bool *type_is_aperture)
{
uint8_t tmp;
write_register(0x80, 0x01);
write_register(0xFF, 0x01);
write_register(0x00, 0x00);
write_register(0xFF, 0x06);
write_register(0x83, read_register(0x83) | 0x04);
write_register(0xFF, 0x07);
write_register(0x81, 0x01);
write_register(0x80, 0x01);
write_register(0x94, 0x6b);
write_register(0x83, 0x00);
uint8_t tries = 50;
while (read_register(0x83) == 0x00) {
tries--;
if (tries == 0) {
return false;
}
hal.scheduler->delay(1);
}
write_register(0x83, 0x01);
tmp = read_register(0x92);
*count = tmp & 0x7f;
*type_is_aperture = (tmp >> 7) & 0x01;
write_register(0x81, 0x00);
write_register(0xFF, 0x06);
write_register(0x83, read_register(0x83) & ~0x04);
write_register(0xFF, 0x01);
write_register(0x00, 0x01);
write_register(0xFF, 0x00);
write_register(0x80, 0x00);
return true;
}
// Get sequence step enables
// based on VL53L0X_GetSequenceStepEnables()
void AP_RangeFinder_VL53L0X::getSequenceStepEnables(SequenceStepEnables * enables)
{
uint8_t sequence_config = read_register(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 the VCSEL pulse period in PCLKs for the given period type.
// based on VL53L0X_get_vcsel_pulse_period()
uint8_t AP_RangeFinder_VL53L0X::getVcselPulsePeriod(vcselPeriodType _type)
{
#define decodeVcselPeriod(reg_val) (((reg_val) + 1) << 1)
if (_type == VcselPeriodPreRange) {
return decodeVcselPeriod(read_register(PRE_RANGE_CONFIG_VCSEL_PERIOD));
} else if (_type == VcselPeriodFinalRange) {
return decodeVcselPeriod(read_register(FINAL_RANGE_CONFIG_VCSEL_PERIOD));
}
return 255;
}
// Convert sequence step timeout from MCLKs to microseconds with given VCSEL period in PCLKs
// based on VL53L0X_calc_timeout_us()
uint32_t AP_RangeFinder_VL53L0X::timeoutMclksToMicroseconds(uint16_t timeout_period_mclks, uint8_t vcsel_period_pclks)
{
#define calcMacroPeriod(vcsel_period_pclks) ((((uint32_t)2304 * (vcsel_period_pclks) * 1655) + 500) / 1000)
uint32_t macro_period_ns = calcMacroPeriod(vcsel_period_pclks);
return ((timeout_period_mclks * macro_period_ns) + (macro_period_ns / 2)) / 1000;
}
// 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 AP_RangeFinder_VL53L0X::decodeTimeout(uint16_t reg_val)
{
// format: "(LSByte * 2^MSByte) + 1"
return (uint16_t)((reg_val & 0x00FF) <<
(uint16_t)((reg_val & 0xFF00) >> 8)) + 1;
}
// 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 AP_RangeFinder_VL53L0X::getSequenceStepTimeouts(SequenceStepEnables const * enables, SequenceStepTimeouts * timeouts)
{
timeouts->pre_range_vcsel_period_pclks = getVcselPulsePeriod(VcselPeriodPreRange);
timeouts->msrc_dss_tcc_mclks = read_register(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(read_register16(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(read_register16(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);
}
// Get the measurement timing budget in microseconds
// based on VL53L0X_get_measurement_timing_budget_micro_seconds()
// in us
uint32_t AP_RangeFinder_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;
}
// Convert sequence step timeout from microseconds to MCLKs with given VCSEL period in PCLKs
// based on VL53L0X_calc_timeout_mclks()
uint32_t AP_RangeFinder_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);
}
// 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 AP_RangeFinder_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);
}
return 0;
}
// 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 AP_RangeFinder_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;
}
write_register16(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;
}
bool AP_RangeFinder_VL53L0X::init()
{
// setup for 2.8V operation
write_register(VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV,
read_register(VHV_CONFIG_PAD_SCL_SDA__EXTSUP_HV) | 0x01);
// "Set I2C standard mode"
write_register(0x88, 0x00);
write_register(0x80, 0x01);
write_register(0xFF, 0x01);
write_register(0x00, 0x00);
stop_variable = read_register(0x91);
write_register(0x00, 0x01);
write_register(0xFF, 0x00);
write_register(0x80, 0x00);
// disable SIGNAL_RATE_MSRC (bit 1) and SIGNAL_RATE_PRE_RANGE (bit 4) limit checks
write_register(MSRC_CONFIG_CONTROL, read_register(MSRC_CONFIG_CONTROL) | 0x12);
// set final range signal rate limit to 0.25 MCPS (million counts per second)
write_register16(FINAL_RANGE_CONFIG_MIN_COUNT_RATE_RTN_LIMIT, uint16_t(0.25 * (1 << 7)));
write_register(SYSTEM_SEQUENCE_CONFIG, 0xFF);
uint8_t spad_count;
bool spad_type_is_aperture;
if (!get_SPAD_info(&spad_count, &spad_type_is_aperture)) {
printf("VL53L0X: Failed to get SPAD info\n");
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];
if (!dev->read_registers(GLOBAL_CONFIG_SPAD_ENABLES_REF_0, ref_spad_map, 6)) {
printf("VL53L0X: Failed to read SPAD map\n");
return false;
}
// -- VL53L0X_set_reference_spads() begin (assume NVM values are valid)
write_register(0xFF, 0x01);
write_register(DYNAMIC_SPAD_REF_EN_START_OFFSET, 0x00);
write_register(DYNAMIC_SPAD_NUM_REQUESTED_REF_SPAD, 0x2C);
write_register(0xFF, 0x00);
write_register(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++;
}
}
uint8_t reg_spad_map[7] = { GLOBAL_CONFIG_SPAD_ENABLES_REF_0, };
memcpy(&reg_spad_map[1], ref_spad_map, 6);
dev->transfer(reg_spad_map, 7, nullptr, 0);
for (uint16_t i=0; i<ARRAY_SIZE(tuning_data); i++) {
write_register(tuning_data[i].reg, tuning_data[i].value);
}
write_register(SYSTEM_INTERRUPT_CONFIG_GPIO, 0x04);
write_register(GPIO_HV_MUX_ACTIVE_HIGH, read_register(GPIO_HV_MUX_ACTIVE_HIGH) & ~0x10); // active low
write_register(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
write_register(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
write_register(SYSTEM_SEQUENCE_CONFIG, 0x01);
if (!performSingleRefCalibration(0x40)) {
printf("VL53L0X: Failed SingleRefCalibration1\n");
return false;
}
// -- VL53L0X_perform_vhv_calibration() end
// -- VL53L0X_perform_phase_calibration() begin
write_register(SYSTEM_SEQUENCE_CONFIG, 0x02);
if (!performSingleRefCalibration(0x00)) {
printf("VL53L0X: Failed SingleRefCalibration2\n");
return false;
}
// -- VL53L0X_perform_phase_calibration() end
// "restore the previous Sequence Config"
write_register(SYSTEM_SEQUENCE_CONFIG, 0xE8);
start_continuous();
// call timer() every 33ms. We expect new data to be available every 33ms
dev->register_periodic_callback(33000,
FUNCTOR_BIND_MEMBER(&AP_RangeFinder_VL53L0X::timer, void));
return true;
}
// based on VL53L0X_perform_single_ref_calibration()
bool AP_RangeFinder_VL53L0X::performSingleRefCalibration(uint8_t vhv_init_byte)
{
write_register(SYSRANGE_START, 0x01 | vhv_init_byte); // VL53L0X_REG_SYSRANGE_MODE_START_STOP
uint8_t tries = 200;
while ((read_register(RESULT_INTERRUPT_STATUS) & 0x07) == 0) {
if (tries-- == 0) {
return false;
}
hal.scheduler->delay(1);
}
write_register(SYSTEM_INTERRUPT_CLEAR, 0x01);
write_register(SYSRANGE_START, 0x00);
return true;
}
// Start continuous ranging measurements
void AP_RangeFinder_VL53L0X::start_continuous(void)
{
write_register(0x80, 0x01);
write_register(0xFF, 0x01);
write_register(0x00, 0x00);
write_register(0x91, stop_variable);
write_register(0x00, 0x01);
write_register(0xFF, 0x00);
write_register(0x80, 0x00);
// continuous back-to-back mode
write_register(SYSRANGE_START, 0x02); // VL53L0X_REG_SYSRANGE_MODE_BACKTOBACK
start_ms = AP_HAL::millis();
}
// read - return last value measured by sensor
bool AP_RangeFinder_VL53L0X::get_reading(uint16_t &reading_mm)
{
if ((read_register(RESULT_INTERRUPT_STATUS) & 0x07) == 0) {
if (AP_HAL::millis() - start_ms > 200) {
start_continuous();
}
return false;
}
// assumptions: Linearity Corrective Gain is 1000 (default);
// fractional ranging is not enabled
reading_mm = read_register16(RESULT_RANGE_STATUS + 10);
write_register(SYSTEM_INTERRUPT_CLEAR, 0x01);
return true;
}
void AP_RangeFinder_VL53L0X::write_register16(uint8_t reg, uint16_t value)
{
uint8_t b[3] = { reg, uint8_t(value>>8), uint8_t(value) };
dev->transfer(b, 3, nullptr, 0);
}
void AP_RangeFinder_VL53L0X::write_register(uint8_t reg, uint8_t value)
{
dev->write_register(reg, value);
}
uint8_t AP_RangeFinder_VL53L0X::read_register(uint8_t reg)
{
uint8_t v = 0;
dev->read_registers(reg, &v, 1);
return v;
}
uint16_t AP_RangeFinder_VL53L0X::read_register16(uint8_t reg)
{
uint16_t v = 0;
dev->transfer(&reg, 1, (uint8_t *)&v, 2);
return be16toh(v);
}
/*
update the state of the sensor
*/
void AP_RangeFinder_VL53L0X::update(void)
{
if (counter > 0) {
state.distance_m = (sum_mm * 0.001f) / counter;
state.last_reading_ms = AP_HAL::millis();
sum_mm = 0;
counter = 0;
update_status();
} else {
set_status(RangeFinder::Status::NoData);
}
}
void AP_RangeFinder_VL53L0X::timer(void)
{
uint16_t range_mm;
if (get_reading(range_mm) && range_mm < 8000) {
sum_mm += range_mm;
counter++;
}
}
#endif // AP_RANGEFINDER_VL53L0X_ENABLED