SHENG-HEN HSIEH
/
VL53L0X_STM32compatible
Modified from arduino library https://github.com/pololu/vl53l0x-arduino
Revision 0:d738e3a03cf8, committed 2017-02-16
- Comitter:
- open4416
- Date:
- Thu Feb 16 08:45:17 2017 +0000
- Commit message:
- works fine on STM32 without state check but high speed ; >200Hz
Changed in this revision
diff -r 000000000000 -r d738e3a03cf8 VL53L0X_SH.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/VL53L0X_SH.cpp Thu Feb 16 08:45:17 2017 +0000 @@ -0,0 +1,983 @@ +// 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 <VL53L0X_SH.h> +#include "mbed.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 + +// 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 && ((short)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) ((((long)2304 * (vcsel_period_pclks) * 1655) + 500) / 1000) + +// Constructors //////////////////////////////////////////////////////////////// +I2C i2c(D14, D15); //I2C reg(SDA, SCL) + +VL53L0X::VL53L0X(void) + : address(ADDRESS_DEFAULT) + , io_timeout(0) // no timeout + , did_timeout(false) +{ +} + +// Public Methods ////////////////////////////////////////////////////////////// + +void VL53L0X::setAddress(char new_addr) +{ + writeReg(I2C_SLAVE_DEVICE_ADDRESS, new_addr & 0x7F); + address = new_addr; +} + +// 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) +{ + 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 + + char 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 + char 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); + + char first_spad_to_enable = spad_type_is_aperture ? 12 : 0; // 12 is the first aperture spad + char spads_enabled = 0; + + for (char 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(char reg, char value) +{ + data_w_2[0] = reg; + data_w_2[1] = value; + i2c.write( address<<1 | 0x00, data_w_2, 2, 0); +} + +// Write a 16-bit register +void VL53L0X::writeReg16Bit(char reg, short value) +{ + data_w_3[0] = reg; + data_w_3[1] = (value >> 8) & 0xFF; + data_w_3[2] = (value ) & 0xFF; + i2c.write( address<<1 | 0x00, data_w_3, 3, 0); +} + +// Write a 32-bit register +void VL53L0X::writeReg32Bit(char reg, long value) +{ + data_w_5[0] = reg; + data_w_5[1] = (value >> 24) & 0xFF; + data_w_5[2] = (value >> 16) & 0xFF; + data_w_5[3] = (value >> 8) & 0xFF; + data_w_5[4] = (value ) & 0xFF; + i2c.write( address<<1 | 0x00, data_w_5, 5, 0); +} + +// Read an 8-bit register +char VL53L0X::readReg(char reg) +{ + char value[1]; + data_r_1[0] = reg; + i2c.write( address<<1 | 0x00, data_r_1, 1, 0); + i2c.read ( address<<1 | 0x01, value, 1, 0); + return value[0]; +} + +// Read a 16-bit register +short VL53L0X::readReg16Bit(char reg) +{ + short value; + data_r_1[0] = reg; + i2c.write( address<<1 | 0x00, data_r_1, 1, 0); + i2c.read ( address<<1 | 0x01, data_r_2, 2, 0); + value = data_r_2[0] << 8 | data_r_2[1]; + return value; +} + +// Read a 32-bit register +long VL53L0X::readReg32Bit(char reg) +{ + long value; + data_r_1[0] = reg; + i2c.write( address<<1 | 0x00, data_r_1, 1, 0); + i2c.read ( address<<1 | 0x01, data_r_4, 4, 0); + value = data_r_4[0] << 24; + value |= data_r_4[1] << 16; + value |= data_r_4[2] << 8; + value |= data_r_4[3] ; + return value; +} + +// Write an arbitrary number of bytes from the given array to the sensor, +// starting at the given register +void VL53L0X::writeMulti(char reg, char const * src, char count) +{ + char data_w_n[count]; + data_w_n[0] = reg; + for(int i=0; i<count; i++) { + data_w_n[i+1] = *(src+i); + } + i2c.write( address<<1 | 0x00, data_w_n, count, 0); +} + +// Read an arbitrary number of bytes from the sensor, starting at the given +// register, into the given array +void VL53L0X::readMulti(char reg, char * dst, char count) +{ + char data_r_n[count]; + data_r_1[0] = reg; + i2c.write( address<<1 | 0x00, data_r_1, 1, 0); + i2c.read ( address<<1 | 0x01, data_r_n, count, 0); + for(int i=0; i<count; i++) { + *(dst+i) = data_r_n[i]; + } +} + +// 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 > 511.99f) { + 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(long budget_us) +{ + SequenceStepEnables enables; + SequenceStepTimeouts timeouts; + + short const StartOverhead = 1320; // note that this is different than the value in get_ + short const EndOverhead = 960; + short const MsrcOverhead = 660; + short const TccOverhead = 590; + short const DssOverhead = 690; + short const PreRangeOverhead = 660; + short const FinalRangeOverhead = 550; + + long const MinTimingBudget = 20000; + + if (budget_us < MinTimingBudget) { + return false; + } + + long 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; + } + + long 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." + + short 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 +long VL53L0X::getMeasurementTimingBudget(void) +{ + SequenceStepEnables enables; + SequenceStepTimeouts timeouts; + + short const StartOverhead = 1910; // note that this is different than the value in set_ + short const EndOverhead = 960; + short const MsrcOverhead = 660; + short const TccOverhead = 590; + short const DssOverhead = 690; + short const PreRangeOverhead = 660; + short const FinalRangeOverhead = 550; + + // "Start and end overhead times always present" + long 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, char period_pclks) +{ + char 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) + + short 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) + + short 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." + + short 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 + + char 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() +char 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(long 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 + + short 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) +short VL53L0X::readRangeContinuousMillimeters(void) +{ +// startTimeout(); +// while ((readReg(RESULT_INTERRUPT_STATUS) & 0x07) == 0) { +// if (checkTimeoutExpired()) { +// did_timeout = true; +// return 32767; +// } +// } + + // assumptions: Linearity Corrective Gain is 1000 (default); + // fractional ranging is not enabled + short 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() +short 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 32767; +// } +// } + + 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(char * count, bool * type_is_aperture) +{ + char 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(); + wait_ms(1); + 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) +{ + char 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 long, but the return value is +// always stored in a short. +short VL53L0X::decodeTimeout(short reg_val) +{ + // format: "(LSByte * 2^MSByte) + 1" + return (short)((reg_val & 0x00FF) << + (short)((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 short, but the argument passed to it +// is always a short. +short VL53L0X::encodeTimeout(short timeout_mclks) +{ + // format: "(LSByte * 2^MSByte) + 1" + + long ls_byte = 0; + short 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() +long VL53L0X::timeoutMclksToMicroseconds(short timeout_period_mclks, char vcsel_period_pclks) +{ + long 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() +long VL53L0X::timeoutMicrosecondsToMclks(long timeout_period_us, char vcsel_period_pclks) +{ + long 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(char vhv_init_byte) +{ + writeReg(SYSRANGE_START, 0x01 | vhv_init_byte); // VL53L0X_REG_SYSRANGE_MODE_START_STOP + +// startTimeout(); + wait_ms(1); + while ((readReg(RESULT_INTERRUPT_STATUS) & 0x07) == 0) { +// if (checkTimeoutExpired()) { +// return false; +// } + } + + writeReg(SYSTEM_INTERRUPT_CLEAR, 0x01); + + writeReg(SYSRANGE_START, 0x00); + + return true; +}
diff -r 000000000000 -r d738e3a03cf8 VL53L0X_SH.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/VL53L0X_SH.h Thu Feb 16 08:45:17 2017 +0000 @@ -0,0 +1,182 @@ +#ifndef VL53L0X_SH_h +#define VL53L0X_SH_h +#include "mbed.h" + +extern I2C i2c; +class VL53L0X +{ +public: + // register addresses from API vl53l0x_device.h (ordered as listed there) + 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, + }; + + enum vcselPeriodType { VcselPeriodPreRange, VcselPeriodFinalRange }; + + char last_status; // status of last I2C transmission + + VL53L0X(void); + + void setAddress(char new_addr); + inline char getAddress(void) { + return address; + } + + bool init(bool io_2v8 = true); + + void writeReg(char reg, char value); + void writeReg16Bit(char reg, short value); + void writeReg32Bit(char reg, long value); + char readReg(char reg); + short readReg16Bit(char reg); + long readReg32Bit(char reg); + + void writeMulti(char reg, char const * src, char count); + void readMulti(char reg, char * dst, char count); + + bool setSignalRateLimit(float limit_Mcps); + float getSignalRateLimit(void); + + bool setMeasurementTimingBudget(long budget_us); + long getMeasurementTimingBudget(void); + + bool setVcselPulsePeriod(vcselPeriodType type, char period_pclks); + char getVcselPulsePeriod(vcselPeriodType type); + + void startContinuous(long period_ms = 0); + void stopContinuous(void); + short readRangeContinuousMillimeters(void); + short readRangeSingleMillimeters(void); + + inline void setTimeout(short timeout) { + io_timeout = timeout; + } + inline short getTimeout(void) { + return io_timeout; + } + bool timeoutOccurred(void); + +private: + // TCC: Target CentreCheck + // MSRC: Minimum Signal Rate Check + // DSS: Dynamic Spad Selection + + struct SequenceStepEnables { + bool tcc, msrc, dss, pre_range, final_range; + }; + + struct SequenceStepTimeouts { + short pre_range_vcsel_period_pclks, final_range_vcsel_period_pclks; + + short msrc_dss_tcc_mclks, pre_range_mclks, final_range_mclks; + long msrc_dss_tcc_us, pre_range_us, final_range_us; + }; + + char data_w_2[2]; //buff for write + char data_w_3[3]; //buff for write + char data_w_5[5]; //buff for write + char data_r_1[1]; //buff for read + char data_r_2[2]; //buff for read + char data_r_4[4]; //buff for read + char address; + short io_timeout; + bool did_timeout; + short timeout_start_ms; + + char stop_variable; // read by init and used when starting measurement; is StopVariable field of VL53L0X_DevData_t structure in API + long measurement_timing_budget_us; + + bool getSpadInfo(char * count, bool * type_is_aperture); + + void getSequenceStepEnables(SequenceStepEnables * enables); + void getSequenceStepTimeouts(SequenceStepEnables const * enables, SequenceStepTimeouts * timeouts); + + bool performSingleRefCalibration(char vhv_init_byte); + + static short decodeTimeout(short value); + static short encodeTimeout(short timeout_mclks); + static long timeoutMclksToMicroseconds(short timeout_period_mclks, char vcsel_period_pclks); + static long timeoutMicrosecondsToMclks(long timeout_period_us, char vcsel_period_pclks); +}; + +#endif \ No newline at end of file
diff -r 000000000000 -r d738e3a03cf8 main.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Thu Feb 16 08:45:17 2017 +0000 @@ -0,0 +1,84 @@ +#include "mbed.h" +#include "VL53L0X_SH.h" + +#define Rms 5000 //TT rate +#define dt 0.005f +#define NN 200 + +#define constrain(amt,low,high) ((amt)<(low)?(low):((amt)>(high)?(high):(amt))) + +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓GPIO registor↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +//~~~structure~~~// +DigitalOut led(D13); //detection +DigitalOut TT_ext(D12); + +//~~~VL53L0X_I2C~~~// +//I2C i2c(D14, D15); //I2C reg(SDA, SCL) +VL53L0X sensor; +//~~~Serial~~~// +Serial pc(D1, D0); //Serial reg(TX RX) +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of GPIO registor↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓Varible registor↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +//~~~globle~~~// +Ticker TT; //call a timer +int count = 0; //one second counter for extrenal led blink + +//~~~VL53L0X_I2C~~~// +int Distance = 0; +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of Varible registor↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓Function registor↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +void init_TIMER(); //set TT_main() rate +void TT_main(); //timebase function rated by TT +void init_IO(); //initialize IO state +float lpf(float input, float output_old, float frequency); //lpf discrete +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of Function registor↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓main funtion↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +int main() +{ + init_IO(); //initialized value + sensor.init(); //init SENSOR + sensor.setTimeout(500); + sensor.startContinuous(); + NVIC_SetPriority(TIM5_IRQn, 51); //!!!!!!!!!!!!!!!!!!!!!!!!! + init_TIMER(); //start TT_main + + while(1) { //main() loop + if(count >= NN) { //check if main working + count=0; + led = !led; + } + } + +} +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of main funtion↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓Timebase funtion↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +void init_TIMER() //set TT_main{} rate +{ + TT.attach_us(&TT_main, Rms); +} +void TT_main() //interrupt function by TT +{ + TT_ext = !TT_ext; //indicate TT_main() function working + count = count+1; //one second counter + Distance = sensor.readRangeContinuousMillimeters(); + +//for Serial-Oscilloscope + pc.printf("%d\r", Distance); +} +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of Timebase funtion↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓init_IO funtion↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +void init_IO(void) //initialize +{ + pc.baud(9600); //set baud rate + TT_ext = 0; + led = 0; +} +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of init_IO funtion↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// +//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓lpf funtion↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓// +float lpf(float input, float output_old, float frequency) +{ + float output = 0; + output = (output_old + frequency*dt*input) / (1 + frequency*dt); + return output; +} +//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑end of lpf funtion↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑// \ No newline at end of file
diff -r 000000000000 -r d738e3a03cf8 mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Thu Feb 16 08:45:17 2017 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/176b8275d35d \ No newline at end of file