NodeMCU ESP8266 read data from GP2Y1010AU0F not correct

Projects General Guidance
1

images
I use ESP8266 connect to GP2Y1010AU0F like image. I use this code for run ESP8266.

int dustPin = A0;
int ledPin = 4;    

float voltsMeasured = 0;
float calcVoltage = 0;
float dustDensity = 0;
  
void setup()
{
  Serial.begin(57600);
  pinMode(ledPin,OUTPUT);
}

void loop()
{
  digitalWrite(ledPin,LOW); // power on the LED
  delayMicroseconds(280);
  
  voltsMeasured = analogRead(dustPin); // read the dust value
  
  delayMicroseconds(40);
  digitalWrite(ledPin,HIGH); // turn the LED off
  delayMicroseconds(9680);
  
  //measure your 5v and change below
  calcVoltage = voltsMeasured * (3.3 / 1024.0);
  dustDensity = 0.17 * calcVoltage - 0.1;
  Serial.println("GP2Y1010AU0F readings"); 
  Serial.print("Raw Signal Value = ");
  Serial.println(voltsMeasured); 
  Serial.print("Voltage = ");
  Serial.println(calcVoltage);
  Serial.print("Dust Density = ");
  Serial.println(dustDensity); // mg/m3
  Serial.println("");
  delay(1000);
}

It show output like this which Dust Density is not correct.

GP2Y1010AU0F readings
Raw Signal Value = 104.00
Voltage = 0.34
Dust Density = -0.04

GP2Y1010AU0F readings
Raw Signal Value = 110.00
Voltage = 0.35
Dust Density = -0.04

GP2Y1010AU0F readings
Raw Signal Value = 111.00
Voltage = 0.36
Dust Density = -0.04

How to fix it?

2

Fix what? It looks all okey. What atmosphere do You provide for the sensor?
To get none varying readings You need to use a controlled atmosphere. Normal "at home" atmosphere is not good enough.
Test increasing the 280 microsecond delay by a factor 10, 50, 100....

3

And where did these equations come from? What makes you think they're correct?

4

Also, your schematic shows you powering the sensor with 5V, and then interfacing it with a processor that runs at 3.3V. That's didn't do your ADC input any favours.

5

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