   pressure = myPressure.readPressure();
 
   // Calc light level
-  light_lvl = get_light_level();
-
-  // Calc pH
-  ph = analogRead(PH_PIN) * 5.0 / 1024;
-  ph = 3.5 * ph + PH_OFFSET;
+  //light_lvl = get_light_level();
+
+  // Calc EC
+  delay(500);
+  digitalWrite(S1_EN, LOW);
+  FreqCount.begin(1000);
+  while ( !FreqCount.available());
+  ec = FreqCount.read();
+  FreqCount.end();
+  // TODO: calibrate value
+  digitalWrite(S1_EN, HIGH);
 
   // Calc orp
+  delay(500);
+  digitalWrite(S2_EN, LOW);
+  delay(1000);
   orp = (30.0 * SYSTEM_VOLTAGE * 1000.0) - (75.0 * analogRead(ORP_PIN) *
       SYSTEM_VOLTAGE * 1000 / 1024.0);
   orp = (orp / 75.0) - ORP_OFFSET;
-
-  // Calc EC
-  ec = FreqCount.read();
-  // TODO: calibrate value
+  digitalWrite(S2_EN, HIGH);
+
+  // Calc pH
+  delay(500);
+  digitalWrite(S3_EN, LOW);
+  delay(1000);
+  ph = analogRead(PH_PIN) * 5.0 / 1024;
+  ph = 3.5 * ph + PH_OFFSET;
+  digitalWrite(S3_EN, HIGH);
 
   // Calc water temperature
   wtemp = get_water_temperature();

const byte FONA_RST = 12;
const byte FONA_EN_BAT = 13;

// Analog I/O pins
const byte LIGHT = A5; // Not currently used
const byte REFERENCE_3V3 = A3; // Not currently used
const byte WDIR = A0; // Not currently used
const byte PH_PIN = A4;
const byte ORP_PIN = A3;
const byte WTEMP_PIN = A15;
// Conductivity sensor (EC) uses pin 47 and disables pins 9, 10, 44, 45, 46.

// Offset values

  // Configure the humidity sensor
  myHumidity.begin();

  // Set output pins
  pinMode(S1_EN, OUTPUT);
  digitalWrite(S1_EN, HIGH);
  pinMode(S2_EN, OUTPUT);
  digitalWrite(S2_EN, HIGH);
  pinMode(S3_EN, OUTPUT);
  digitalWrite(S3_EN, HIGH);

  pinMode(MULT_A, OUTPUT);
  digitalWrite(MULT_A, HIGH);
  pinMode(MULT_B, OUTPUT);
  digitalWrite(MULT_B, HIGH);
  pinMode(MULT_C, OUTPUT);
  digitalWrite(MULT_C, LOW);
  
  // Set key pin to low
  pinMode(FONA_KEY, OUTPUT);
  digitalWrite(FONA_KEY, LOW);
