Use of ADCs.

hi. tearing few strands of hair out.  using adc measure various sensor outputs.  not getting expected results decided connect , adc pin 5v 3.3v , gnd.  there little change in outputs.  doing silly , cant determine

i enclose sketch using test.

void setup() {
  int soil_humidity_1 = 4;
  int soil_1_control = 2;
  int k = 1;
  serial.begin(9600);
}

void loop() {
  serial.print("       soil_humidity_1");
  int soil_humidity_1 = 0;
  float av_soil_humidity_1 = 0;
  float t = 0;
  (analogread( soil_humidity_1));
  (analogread(soil_humidity_1));
  (int k = 1 ; k < 11 ; k++ )
  {
    av_soil_humidity_1 += (analogread( soil_humidity_1));
    delay( 100);
  }
  t  = ( av_soil_humidity_1) * 5.00 * 1 / (1024.00 * 10.00);
  delay( 10);
  serial.print ("  ");
  serial.print (analogread( soil_humidity_1));
  serial.print ("  ");
  serial.print (analogread( soil_humidity_1) * 5.00 * 1 / (1024.00));
  serial.print (" ");
  serial.print (t); serial.print ("  ");
  serial.println();
  delay(10000);
}

any suggestions save sanity

write simple program loop() this

code: [select]

void loop() {
    int adcval = analogread(a4);
    serial.print(adcval);
    delay(500);
}

and see happens different voltages on analog pin 4

i suspect problem have these 2 lines inside setup() when should go before setup()

code: [select]

int soil_humidity_1 = 4;
 int soil_1_control = 2;
when define variable inside function visible inside function. when declare outside of functions becomes global variable accessible everywhere.

...r

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