// ACS712 Arduino code //new version with filter

in secrets.h:

//#define useACS712
#define ACS712useFilter true
#define ACS712diag true //false // every second print and now also send to mqtt /log


in main.ino // declare

#ifdef useACS712
float Coffset = 1.650;
float Cfix = 8.190; // aka 5.0/3.3 / 0.185 Vdivider and hall factor
float Ctune = 1.0;  //
float ACS712amp = 0.0;
String ACS712s = "";
// add filter
float Ma = 0.15;
float Mb = 1.0 - Ma;
float A0signal = 0.0;
boolean Finit = true;

#endif



in main.ino // setup

#ifdef useACS712
  msg="ACS712 enabled";
  Serial.println(msg);
#endif

in main.ino // 1 sec job // Ains()  // after reading Ains, before printing values


#ifdef useACS712
// here use the A0 sensorA0val (Volt) and calc about the ACS AMP  ( for 5Amp version 0.185 V/A)
// Coffset = 1.650; // Cfix = 8.190; Ctune = 1.0; ACS712amp = 0.0; ACS712s = ""; // add filter  float Ma = 0.15; float Mb = 1.0 - Ma; float A0signal = 0.0; boolean useFilter = true; boolean Finit = true;

  //sensorA0val = 1.65;  // _____________________________ simulate input test if no hardware available

  if ( Finit ) {
    Finit = false;
    A0signal = sensorA0val;  // ________________________ init to avoid the first 15 sec SWING IN
  }
  if ( ACS712useFilter ) {
    A0signal = Ma * sensorA0val + Mb * A0signal;
  } else {
    A0signal = sensorA0val;
  }
  ACS712amp = ( A0signal - Coffset ) * Cfix * Ctune;

  if ( ACS712diag ) {  // diagnostic print
    // now make diagnostic print a mqtt dataset
    ACS712s = "{ \"input\": "+String(sensorA0val,3)+", \"Ma\": "+String(Ma,3)+", \"Mb\": "+String(Mb,3)+", \"Filter\": "+String(ACS712useFilter)+", \"A0signal\": "+String(A0signal,3)+", \"Coffset\": "+String(Coffset,3)+", \"Cfix\": "+String(Cfix,3)+", \"Ctune\": "+String(Ctune,3)+", \"ACS712amp\": " + String(ACS712amp,3)+" }";
    Serial.println(ACS712s);
    BootLog = ACS712s;
    send_MQTT_LOG();
  }
  sensorA0val = ACS712amp;     // ________________________  temporary overwrite the measured Volt with the ACS712 calculation and it goes all the way to broker and database without any code

#endif