Greetings.
I am using the VL53L1CB and I am seeing it report valid range data when it shouldn’t.
I place a target in front of the VL53L1CB and it reports the distance to the target without any problems. However, when I remove the target and the VL53L1CB points off into an out-of-range distance, it will continue to report the same value for a while before it decides that it can no longer acquire the range (i.e. rangeData.RangeStatus is still reporting success after the target is removed).
This duration of this behavior seems to be dependent on what is behind the target.
Is there a way to always immediately report when the target has been removed?
Thank you
Scott Wild
This is the data I'm seeing. Note that I remove the target at 3.2 seconds.
Here is my sampling code (note: I updated the code snippet by adding the ROI setting code because it seems to make the problem easier to duplicate)
VL53L1_software_reset( &vl53l1Dev );
VL53L1_DataInit( &vl53l1Dev );
VL53L1_StaticInit( &vl53l1Dev );
VL53L1_SetPresetMode( &vl53l1Dev, VL53L1_PRESETMODE_RANGING );
VL53L1_SetDistanceMode( &vl53l1Dev, VL53L1_DISTANCEMODE_MEDIUM );
// Move ROI higher to reduce reflections from the floor
VL53L1_RoiConfig_t roiConfig;
roiConfig.NumberOfRoi = 1;
roiConfig.UserRois[0].TopLeftX = 6;
roiConfig.UserRois[0].TopLeftY = 15;
roiConfig.UserRois[0].BotRightX = 9;
roiConfig.UserRois[0].BotRightY = 12;
VL53L1_SetROI(&vl53l1Dev, &roiConfig);
while (1)
{
// If we're not taking a reading, start a measurement
if( !takingReading )
{
if( VL53L1_ClearInterruptAndStartMeasurement( &vl53l1Dev ) == 0 )
takingReading = true;
else
range = 0;
}
else // Waiting for a reading to complete
{
// If the reading has completed
uint8_t ready = 0;
VL53L1_GetMeasurementDataReady( &vl53l1Dev, &ready );
if( ready )
{
VL53L1_RangingMeasurementData_t rangeData;
if( VL53L1_GetRangingMeasurementData( &vl53l1Dev, &rangeData ) == 0 )
{
// If the sensor chip returned a valid value
if( rangeData.RangeStatus == 0 )
range = rangeData.RangeMilliMeter;
else
range = 0;
}
else
range = 0;
takingReading = false;
}
}
}