Vl53l0x - high accuracy mode (tcc)

Other Hardware Sensors
1

Good morning, afternoon or evening!

I am using the VL53L0X sensor in my measurement related TCC.

I'm carrying out some tests, but I couldn't get precision with the sensor, apparently after 100mm it loses precision and sometimes in measurements smaller than that there are variations.

I installed the following code:

#include "Adafruit_VL53L0X.h"
const byte VL53LOX_InterruptPin = 6;
const byte VL53LOX_ShutdownPin = 9;
volatile byte VL53LOX_State = LOW;
Adafruit_VL53L0X lox = Adafruit_VL53L0X();

//--------  PINOS UNO -----//
// SDA ADC4
// SCL ADC5

const int numSamples = 10;     // Número de amostras para o filtro de média móvel
int distances[numSamples];     // Array para armazenar as amostras

void setup() {
  //Serial.begin(115200);
  Serial.begin(9600);
  // wait until serial port opens for native USB devices
  while (!Serial) {
    delay(1);
  }
  Serial.println(F("VL53L0X API Interrupt Ranging example\n\n"));

  pinMode(VL53LOX_ShutdownPin, INPUT_PULLUP);
  pinMode(VL53LOX_InterruptPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(VL53LOX_InterruptPin), VL53LOXISR,
                  CHANGE);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, LOW);

  // if lox.begin failes its becasue it was a warm boot and the VL53LOX is in
  // continues mesurement mode we can use an IO pin to reset the device in case
  // we get stuck in this mode
  while (!lox.begin()) {
    Serial.println(F("Failed to boot VL53L0X"));
    Serial.println("Adafruit VL53L0X XShut set Low to Force HW Reset");
    digitalWrite(VL53LOX_ShutdownPin, LOW);
    delay(100);
    digitalWrite(VL53LOX_ShutdownPin, HIGH);
    Serial.println("Adafruit VL53L0X XShut set high to Allow Boot");
    delay(100);
  }

  Serial.println("Set GPIO Config so if range is lower the LowThreshold "
                 "trigger Gpio Pin ");
  lox.setGpioConfig(VL53L0X_DEVICEMODE_CONTINUOUS_RANGING,
                    VL53L0X_GPIOFUNCTIONALITY_THRESHOLD_CROSSED_LOW,
                    VL53L0X_INTERRUPTPOLARITY_LOW);

  // Set Interrupt Treashholds
  // Low reading set to 50mm  High Set to 100mm
  FixPoint1616_t LowThreashHold = (50 * 65536.0);
  FixPoint1616_t HighThreashHold = (100 * 65536.0);
  Serial.println("Set Interrupt Threasholds... ");
  lox.setInterruptThresholds(LowThreashHold, HighThreashHold, true);

  // Enable Continous Measurement Mode
  Serial.println("Set Mode VL53L0X_DEVICEMODE_CONTINUOUS_RANGING... ");
  lox.setDeviceMode(VL53L0X_DEVICEMODE_CONTINUOUS_RANGING, false);

  Serial.println("StartMeasurement... ");
  lox.startMeasurement();
}//---FINAL SETUP

void VL53LOXISR() {
  // Read if we are high or low
  VL53LOX_State = digitalRead(VL53LOX_InterruptPin);
  // set the built in LED to reflect in range on for Out of range off for in
  // range
  digitalWrite(LED_BUILTIN, VL53LOX_State);
}


//---------------------------------------------------------------------------------------//
//---------------------------------------------------------------------------------------//
void loop() {
  if (VL53LOX_State == LOW) {
    VL53L0X_RangingMeasurementData_t measure;
    lox.getRangingMeasurement(
      &measure, false); // pass in 'true' to get debug data printout!
    lox.clearInterruptMask(false);

    ////////////////////////////////////////////////////////////////////////////////////////////
    // Adicionar nova amostra no início do array
    for (int i = numSamples - 1; i > 0; i--) {
      distances[i] = distances[i - 1];
    }

    // Armazenar a nova medição na posição 0 do array
    distances[0] = (measure.RangeMilliMeter);

    // Calcular a média das amostras
    int sum = 0;
    for (int i = 0; i < numSamples; i++) {
      sum += distances[i];
    }
    int averageDistance = sum / numSamples;

    // Serial.print("Distancia suavizada: ");
    Serial.println(averageDistance / 1 + (averageDistance % 100) * 0.01, 2);  // Exibir em mm com duas casas decimais
    //Serial.print("Distance (mm): ");
    //Serial.println(averageDistance);  // Exibir em mm com duas casas decimais
    //Serial.println(" mm");
    delay(80);

  } else {

    delay(1);
  }

}//-------------//

//----------------------------//

Please, can anyone tell me to what extent this sensor can return accuracy, in this case the idea would be to measure pieces in up to a maximum of 30cm, I would position the sensor on a base where it would be at the top and the piece at the base bottom, returning me the height of the object.

I tried to implement two decimal places and make a moving average filter, but it's still not giving me a convincing result.

2

Olá! Pode não ser a solução para o seu problema, mas sugiro verificar essas linhas aqui:

Ao declarar sum e averageDistance como int, você pode estar perdendo a precisão na medição.

3

Fiz a alteração, conforme mencionado porem ainda não obtive uma precisão do sensor.
Alem de tudo ele tem não tem uma repetibilidade muito boa, sempre alterna nos resultados.

Não sei o que fazer, não gostaria de trocar o tema do TCC.

4

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