ST VL53L3CX - Offset Calibration

6.2.3 Getting crosstalk calibration results
Calibration results consist, among others, of an histogram and a parameter called “plane offset”. The plane offset
represents the amount of correction applied, and the histogram is the repartition of the correction on each bin.
The function VL53LX_GetCalibrationData() returns all the calibration data. The returned structure
VL53LX_CalibrationData_t contains other structures. The plane offset is contained in
VL53LX_customer_nvm_managed_t:
algo_crosstalk_compensation_plane_offset_kcps is a fixed point 7.9 coded value. It has to be divided by 512 to
get the actual number.
The other relevant structure returned is VL53LX_xtalk_histogram_data_t.
6.2.4 Setting crosstalk calibration data
Once the VL53LX_DataInit() function is called, the customer can load the crosstalk calibration data using:
VL53LX_SetCalibrationData()
It is better to call VL53LX_GetCalibrationData(), modify the parameters described in previous section,
xtalk_histogram structure included, and call VL53LX_SetCalibrationData()
6.2.5 Enable/disable crosstalk compensation
The function VL53LX_SetXTalkCompensationEnable() enables or disables the crosstalk compensation
Note: Crosstalk compensation is disabled by default.
To enable the crosstalk compensation call V53LX_SetXTalkCompensationEnable&VL53L3Dev, 1);
To disable the crosstalk compensation call VL53LX_SetXTalkCompensationEnable&VL53L3Dev, 0);
Note: This function does not perform any calibration or crosstalk data loading, it only enables the compensation.
Note: Calibration or loading of calibration data functions have to be called separately from this enable/disable function
(see sections above).
6.3 Offset calibration
Soldering the device on the customer board or adding a coverglass can introduce an offset in the ranging
distance. This part to part offset has to be measured during the offset calibration.
Offset calibration also allows to calibrate the dmax value, using the same calibration conditions than the offset
calibration.
6.3.1 Offset calibration functions
The following two functions are available for the offset calibration:
• VL53LX_PerformOffsetSimpleCalibration(Dev, CalDistanceMilliMeter)
• VL53LX_PerformOffsetPerVCSELCalibration(Dev, CalDistanceMilliMeter)
The arguments of the functions is the target distance in millimeters. Offset calibration has to be performed after
crosstalk correction.
VL53LX_PerformOffsetPerVCSELCalibration is the most accurate function, but it takes longer to perform the
calibration (time multiplied by 3)
UM2778
Offset calibration
UM2778 - Rev 1
page 16/25