Analog averaging not works

Using Arduino Programming Questions
1

hello,

i use analog reading cumulated average 8 times to get more resolution
my problem is : cumul operation is not made with this part of code

ValADC = analogRead(analogPin);  // read the input pin A0 on Lolin
  SommeValADC = SommeValADC + ValADC;
  Serial.printf("  SommeValADC = %5d  ",SommeValADC);
   i = i + 1;
  if (i > 7)
  {
    //problemo ci dessous
  // pour test only
    LM35DZ_temp = (float) SommeValADC * LM35DZ_MAE ; // MAE lottant initialisé avec 0.0402832;<U+202C>
    // OK ci dessous  !
   //LM35DZ_temp = (float) SommeValADC *  330.0 / 8192.0 ; // avec  10mV par °C  et 8x0124
   Serial.printf("LM35DZ = %5.2f °C ",LM35DZ_temp);
   SommeValADC = 0;

   snprintf(Ana0char,6,"%5.2f",LM35DZ_temp);
   display.setCursor(0,0); 
   display.print(F("A0 LM35DZ         ")); 
   display.setCursor(70,0); 
   display.print(Ana0char); 
   i=0;
  }
  else
  {
    Serial.print(" Ana0=");
    Serial.print(ValADC); 
    Serial.print(" "); 
    
    display.setCursor(0,0); 
       //            123456789012345678
    display.print(F("Compteur          ")); 
    display.setCursor(70,0); 
    snprintf(Oled_Msg,6,"% 5d",Compteur);
    display.print(Oled_Msg);

  }

the printout show not accumulation even i add
SommeValADC = SommeValADC + ValADC;

Compteur= 00303 SommeValADC = 74 LM35DZ = 2.98 °C Pression : 991 Temperat. 23.20 °C Humidite 63.6 BP= BP= OFF ConsigneV = 00000
Compteur= 00304 SommeValADC = 74 Ana0=74 Pression : 991 Temperat. 22.60 °C Humidite 66.5 BP= BP= OFF ConsigneV = 00000
Compteur= 00305 SommeValADC = 74 Ana0=74 Pression : 991 Temperat. 22.70 °C Humidite 63.3 BP= BP= OFF ConsigneV = 00000
Compteur= 00306 SommeValADC = 80 Ana0=80 Pression : 991 Temperat. 23.30 °C Humidite 63.7 BP= BP= OFF ConsigneV = 00000
Compteur= 00307 SommeValADC = 80 Ana0=80 Pression : 991 Temperat. 22.20 °C Humidite 62.4 BP= BP= OFF ConsigneV = 00000
Compteur= 00308 SommeValADC = 80 Ana0=80 Pression : 991 Temperat. 23.30 °C Humidite 69.9 BP= BP= OFF ConsigneV = 00000
Compteur= 00309 SommeValADC = 80 Ana0=80 Pression : 991 Temperat. 22.00 °C Humidite 62.5 BP= BP= OFF ConsigneV = 00000
Compteur= 00310 SommeValADC = 80 Ana0=80 Pression : 991 Temperat. 22.40 °C Humidite 63.0 BP= BP= OFF ConsigneV = 00000
Compteur= 00311 SommeValADC = 80 LM35DZ = 3.22 °C Pression : 991 Temperat. 23.10 °C Humidite 63.5 BP= BP= OFF ConsigneV = 00000

so i get a result of 2.98°C
instead of
about 75 (elementaty ADC measures ) x8 times * 0.0402832= 24.16°C ;
i don't understand why SommeValADC doesnt' increase during the loop from i=0 to i=7 ?

other functions like OLED display , DHT11 , BPM805 are OK ..

‬

2

How and where is SommeValADC declared ?

3

It looks like some code you didn't show is setting SommeValADC to zero before entering the code you did show.

4

We ask you to post all of your code in code tags for very good reasons.

5

Hello,

your are right, a friend tell me my mistake
i had a trailling bad init to zero of SommeValADC near the end of loop

Even with big glasses , sometimes we can't see the evidence ..
because this mistake was not inside my previous version ..

  TempAndHumidity lastValues = dht.getTempAndHumidity();
   if (digitalRead(BP1)==HIGH) BP1_status="OFF"; else BP1_status="ON";
   Compteur ++;
  //  Serial.printf(" Compteur= %05d ",Compteur);
  //  Serial.printf(" LM35DZ= %5.2f °C ",LM35DZ_temp);
        
    SommeValADC = 0;
   Serial.print(" Pression : " + String(p,0));
   Serial.printf(" Temperat. % 5.2f °C ",lastValues.temperature);
   Serial.printf(" Humidite % 3.1f %",lastValues.humidity);
   Serial.printf(" BP= %s",BP1_status);
   Serial.printf(" ConsigneV = %s",Consignechar);
   Serial.println();
   delay(2500);
}

:ok_hand:
thank's

how to mark solved ?

6

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