VL53L1X_calibration.c File Reference

#include "VL53L1X_api.h"
#include "VL53L1X_calibration.h"

Go to the source code of this file.

Macros
#define	ALGO__PART_TO_PART_RANGE_OFFSET_MM   0x001E
#define	MM_CONFIG__INNER_OFFSET_MM   0x0020
#define	MM_CONFIG__OUTER_OFFSET_MM   0x0022

Functions
int8_t	VL53L1X_CalibrateOffset (uint16_t dev, uint16_t TargetDistInMm, int16_t *offset)
	This function performs the offset calibration. The function returns the offset value found and programs the offset compensation into the device. More...
int8_t	VL53L1X_CalibrateXtalk (uint16_t dev, uint16_t TargetDistInMm, uint16_t *xtalk)
	This function performs the xtalk calibration. The function returns the xtalk value found and programs the xtalk compensation to the device. More...

Macro Definition Documentation

ALGO__PART_TO_PART_RANGE_OFFSET_MM

#define ALGO__PART_TO_PART_RANGE_OFFSET_MM   0x001E

Definition at line 69 of file VL53L1X_calibration.c.

MM_CONFIG__INNER_OFFSET_MM

#define MM_CONFIG__INNER_OFFSET_MM   0x0020

Definition at line 70 of file VL53L1X_calibration.c.

MM_CONFIG__OUTER_OFFSET_MM

#define MM_CONFIG__OUTER_OFFSET_MM   0x0022

Definition at line 71 of file VL53L1X_calibration.c.

Function Documentation

VL53L1X_CalibrateOffset()

int8_t VL53L1X_CalibrateOffset	(	uint16_t	dev,
		uint16_t	TargetDistInMm,
		int16_t *	offset
	)

This function performs the offset calibration.
The function returns the offset value found and programs the offset compensation into the device.

Parameters

TargetDistInMm

target distance in mm, ST recommended 100 mm Target reflectance = grey17%

Returns

0:success, !=0: failed

offset pointer contains the offset found in mm

Definition at line 73 of file VL53L1X_calibration.c.

{
    uint8_t i, tmp;
    int16_t AverageDistance = 0;
    uint16_t distance;
    VL53L1X_ERROR status = 0;

    status = VL53L1_WrWord(dev, ALGO__PART_TO_PART_RANGE_OFFSET_MM, 0x0);
    status = VL53L1_WrWord(dev, MM_CONFIG__INNER_OFFSET_MM, 0x0);
    status = VL53L1_WrWord(dev, MM_CONFIG__OUTER_OFFSET_MM, 0x0);
    status = VL53L1X_StartRanging(dev); /* Enable VL53L1X sensor */
    for (i = 0; i < 50; i++) {
        tmp = 0;
        while (tmp == 0){
            status = VL53L1X_CheckForDataReady(dev, &tmp);
        }
        status = VL53L1X_GetDistance(dev, &distance);
        status = VL53L1X_ClearInterrupt(dev);
        AverageDistance = AverageDistance + distance;
    }
    status = VL53L1X_StopRanging(dev);
    AverageDistance = AverageDistance / 50;
    *offset = TargetDistInMm - AverageDistance;
    status = VL53L1_WrWord(dev, ALGO__PART_TO_PART_RANGE_OFFSET_MM, *offset*4);
    return status;
}

VL53L1X_CalibrateXtalk()

int8_t VL53L1X_CalibrateXtalk	(	uint16_t	dev,
		uint16_t	TargetDistInMm,
		uint16_t *	xtalk
	)

This function performs the xtalk calibration.
The function returns the xtalk value found and programs the xtalk compensation to the device.

Parameters

TargetDistInMm

target distance in mm The target distance : the distance where the sensor start to "under range" due to the influence of the photons reflected back from the cover glass becoming strong It's also called inflection point Target reflectance = grey 17%

Returns

0: success, !=0: failed

xtalk pointer contains the xtalk value found in cps (number of photons in count per second)

Definition at line 100 of file VL53L1X_calibration.c.

{
    uint8_t i, tmp;
    float AverageSignalRate = 0;
    float AverageDistance = 0;
    float AverageSpadNb = 0;
    uint16_t distance = 0, spadNum;
    uint16_t sr;
    VL53L1X_ERROR status = 0;
    uint32_t calXtalk;

    status = VL53L1_WrWord(dev, 0x0016,0);
    status = VL53L1X_StartRanging(dev);
    for (i = 0; i < 50; i++) {
        tmp = 0;
        while (tmp == 0){
            status = VL53L1X_CheckForDataReady(dev, &tmp);
        }
        status= VL53L1X_GetSignalRate(dev, &sr);
        status= VL53L1X_GetDistance(dev, &distance);
        status = VL53L1X_ClearInterrupt(dev);
        AverageDistance = AverageDistance + distance;
        status = VL53L1X_GetSpadNb(dev, &spadNum);
        AverageSpadNb = AverageSpadNb + spadNum;
        AverageSignalRate =
            AverageSignalRate + sr;
    }
    status = VL53L1X_StopRanging(dev);
    AverageDistance = AverageDistance / 50;
    AverageSpadNb = AverageSpadNb / 50;
    AverageSignalRate = AverageSignalRate / 50;
    /* Calculate Xtalk value */
    calXtalk = (uint16_t)(512*(AverageSignalRate*(1-(AverageDistance/TargetDistInMm)))/AverageSpadNb);
    *xtalk = (uint16_t)(calXtalk*1000)>>9;
    status = VL53L1_WrWord(dev, 0x0016, calXtalk);
    return status;
}