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Compiler/OPT3101EVM: opt3101

user6095279
Prodigy 90 points
Part Number: OPT3101EVM

Tool/software: TI C/C++ Compiler

hi sir

I copied my own board according to the official development board OPT3101EVM.It can be used normally.But I have two questions for you to answer.
1. The phase will be negative for extremely close distance.Is it a dead zone?
2. How to distinguish between infinite distance and infinite distance? The state is that the signal strength is very small, and the phase outputs more than 60,000 such values.Since we are using a drone, we have to distinguish between the infinite near and the infinite far.

  • 0
    TI__Mastermind 25895 points

    Hi,

    Has this custom board been calibrated?

    Best,

    Alex

  • 0 in reply to Alex Bhandari-Young
    Prodigy 90 points

    hi

    Of course it's calibrated. The distance display is normal, I suspect it is my current setting problem. Please help me to see my configuration. I'd like to have a range of 5 meters above 15 percent reflectivity. My setting is. I use the SDK to calibrate four times, namely hdr0 ﹣ tx0, HDR1 ﹣ tx0, hdr0 ﹣ TX1 and HDR1 ﹣ TX1. But when hdr0 ﹣ tx0 and HDR1 ﹣ tx0 are in progress, it is difficult for the amp ﹣ out to reach 16000-24000

    this->reg.command0 = 0x108; // //Set Channel 1
     this->reg.command1 = 0xB02; // //COMP1.
     this->reg.command2 = 0x100; // //Set Channel 0
     this->reg.command3 = 0xC00; // //COMP1_INV
     this->reg.compare_reg1 = 28000; // //ThresholdH
     this->reg.compare_reg2 = 1750; // //ThresholdH
     this->reg.mux_sel_compin = 0; // //Selects Amplitude for Comparison
     this->reg.en_tx1_on_tx0 = 1; // //Setting TX1 register and connect to TX0
     this->reg.en_processor_values = 1; // //Enables processor values
     this->reg.en_sequencer = 1; // //Enables the Sequencer
     this->reg.hdr_thr_high = 27500; // //High Threshold
     this->reg.hdr_thr_low = 2250; // //Low Threshold
     this->reg.en_adaptive_hdr = 1; // //Enables adaptive HDR feature
     this->reg.illum_dac_h_tx0 = 4; // //High Current settings [011.2mA:5.6mA X 02]
     this->reg.illum_scale_h_tx0 = 0; // //Illum scale for H [011.2mA:5.6mA X 02]
     this->reg.illum_dac_l_tx0 = 2; // //High Current settings [002.8mA:2.8mA X 01]
     this->reg.illum_scale_l_tx0 = 2; // //Illum scale for H [002.8mA:2.8mA X 01]
     this->reg.illum_dac_h_tx1 = 31; // //High Current settings [173.6mA:5.6mA X 31]
     this->reg.illum_scale_h_tx1 = 0; // //Illum scale for H [173.6mA:5.6mA X 31]
     this->reg.illum_dac_l_tx1 = 31; // //High Current settings [043.4mA:1.4mA X 31]
     this->reg.illum_scale_l_tx1 = 3; // //Illum scale for H [043.4mA:1.4mA X 31]
  • 0 in reply to user6095279
    TI__Mastermind 25895 points

    Hi,

    To answer your questions,

    1) If phase goes negative this is not a dead zone but rather likely due to the phase offset calibration. If the phase offset was set such that 0m corresponds to some value x of phase then any phase less than x will wrap around and report a very large phase - is this what you mean by "going negative"? This would either be due to inaccuracy in calibration causing error or another source of error at close distance causing lower than expected phase. Depending on spacing between photodiode and LED there may also be triangulation error at very close distances. With the EVM design which is optimized for long range this can happen at very close distances (<5cm).

    2) Can you clarify what you mean by "infinite near and the infinite far." here

    Best,

    Alex

  • 0 in reply to Alex Bhandari-Young
    Prodigy 90 points

    HI

    1. Is there any good way to avoid this negative phase problem?I can feel that it is the calibration of the low current level. However, I also use reflective tape for this step, but it is almost impossible to reach the signal strength between 16000 and 24000. It is likely to be lower than the HDR switching limit 4929 that I set.What to do?

    2. Infinite near and infinite far are those that fully cover the lens and completely exceed the range.I understand that in principle it's all part of the same state of not being able to receive and send.But what if I want to differentiate this state?

  • 0 in reply to user6095279
    TI__Mastermind 25895 points

    Hi,

    1) You can see a workaround we use on the EVM here: https://e2e.ti.com/support/sensors/f/1023/p/905801/3350151

    2) "near infinite" usually needs a pretty good seal and IR blocking around the photodiode. If an object is placed against the sensor is there still some leakage? If so this would show up as amplitude codes from the device and could be used to distinguish from no targets at all "far infinite" where there would be no amplitude except for the residue crosstalk.

    Best,

    Alex