Thanks Julien!
My doubt is related to the fact that the way of managing the timing of the two ToF types seems different. I hope I can explain my problem well. I have tried two strategies to manage different VL53L3CX ToF (let's consider the case of 6 ToF).
------------------FIRST STRATEGY--------------------
do
{
for(ToF=0; ToF<6;ToF++)
{
start = HAL_GetTick();
if(ToF==0)
{
printf("____________________________________________________________________________________");
}
status = VL53LX_GetMeasurementDataReady(Dev[ToF], &NewDataReady);
while (NewDataReady == 0)
{
status = VL53LX_GetMeasurementDataReady(Dev[ToF], &NewDataReady);
}
if((!status)&&(NewDataReady!=0)){
status = VL53LX_GetMultiRangingData(Dev[ToF], pMultiRangingData);
no_of_object_found=pMultiRangingData->NumberOfObjectsFound;
printf("\n\r ToF %d Count=%5d, ", ToF, pMultiRangingData->StreamCount);
printf("#Objs=%1d ", no_of_object_found);
for(j=0;j<no_of_object_found;j++){
if(j!=0)printf("\n\r\t\t\t ");
printf("status=%d, D=%5dmm, Signal=%2.2f Mcps, Ambient=%2.2f Mcps",
pMultiRangingData->RangeData[j].RangeStatus,
pMultiRangingData->RangeData[j].RangeMilliMeter,
pMultiRangingData->RangeData[j].SignalRateRtnMegaCps/65536.0,
pMultiRangingData->RangeData[j].AmbientRateRtnMegaCps/65536.0);
}
if (status==0){
status = VL53LX_ClearInterruptAndStartMeasurement(Dev[ToF]);
}
}
}
}
while (1);
-----------------------SECOND STRATEGY------------------------
for( ; ; )
{
for(ToF=0; ToF<6; ToF++)
{
status = VL53LX_GetMeasurementDataReady(Dev[ToF], &NewDataReady[ToF]);
while (NewDataReady[ToF] == 0)
{
status = VL53LX_GetMeasurementDataReady(Dev[ToF], &NewDataReady[ToF]);
}
if(status !=0)
{
while(1)
{
printf("\n\rERROR!!!");
}
}
}
for(ToF=0; ToF<6; ToF++)
{
if(NewDataReady[ToF]!=0)
{
status = VL53LX_GetMultiRangingData(Dev[ToF], pMultiRangingData);
if(status !=0)
{
while(1)
{
printf("\n\rERROR!!!");
}
}
no_of_object_found=pMultiRangingData->NumberOfObjectsFound;
printf("ToF %d Count=%5d, ",ToF, pMultiRangingData->StreamCount);
printf("#Objs=%1d ", no_of_object_found);
for(j=0;j<no_of_object_found;j++)
{
if(j!=0)printf("\n\r\t\t\t ");
printf("status=%d, D=%5dmm, Signal=%2.2f Mcps, Ambient=%2.2f Mcps",
pMultiRangingData->RangeData[j].RangeStatus,
pMultiRangingData->RangeData[j].RangeMilliMeter,
pMultiRangingData->RangeData[j].SignalRateRtnMegaCps/65536.0,
pMultiRangingData->RangeData[j].AmbientRateRtnMegaCps/65536.0);
}
printf("\n\r");
}
}
for(ToF=0; ToF<6; ToF++)
{
status = VL53LX_ClearInterruptAndStartMeasurement(Dev[ToF]);
if(status !=0)
{
while(1)
{
printf("\n\rERROR!!!");
}
}
}
printf("\n\r__________________________________________________________________________________\n\r");
}
Both strategies are preceded by reset, set, initialization of the devices and the launch of the StartMeasurement driver function for each of the ToF.
In the first strategy I would like to execute the flow of instructions: VL53LX_GetMeasurementDataReady (Dev [ToF], & NewDataReady) -> VL53LX_GetMultiRangingData (Dev [ToF], pMultiRangingData) -> VL53LX_ClearInterruptAndStart [ToFeasurement] one ToF at a time
In the second strategy, on the other hand, I throw every single instruction 6 times before moving on to the next instruction.
Both of these strategies seem to work well for small timing budgets (8-30 ms), but when setting high timing budgets the ToFs don't work well. I believe this means that I am mishandling the 6 ToFs.
I could not verify if this also happens for the ToF VL53L1X, but comparing the two User Manuals I realized that while the VL53L3CX provide the information of the i-th measurement while the measurement (i + 1) is carried out, in the case of the VL53L1X the information of the i-th measurement is obtained during the inter-measured.period preceding the measurement (i + 1).
Considering all this, I would like to know if the performance problem, in the case of 6 ToF, is related to different aspects of timing compared to the VL53L1X or if I did not write the code well and I did not respect the ranging flow for the VL53L3CX.
Thanks again for answering my question
Vincenzo
I have captured two images of my desktop while TeraTerm shows the ranging information. In the first case there are 6 ToF with Timing Budget = 20 ms, in the second case always 6 ToF with Timing Budget = 500 ms. The initial conditions, excluding TB, are practically the same. 6 sensors placed in line and an object placed at a distance of about 7-10 cm from the 6 sensors. What I don't understand is why in the first case the measurement is clean, with no "holes", while in the second case there are "holes" and some range status different from zero (often status = 12 which should means that there is a target but the signal is too low)
I hope that this will make it clearer
