Incorrect Readings When Digital and Analog Sensor Share Common GND/PWR

Other Hardware Sensors
3

Yeah sorry about that giant image, fixed it.

PIR Sensor (Panasonic AMN23111 Spot Sensor) : http://pewa.panasonic.com/assets/pcsd/catalog/napion-catalog.pdf
Ultrasonic Sensor (Maxbotix LV-EZ3) : http://maxbotix.com/documents/MB1030_Datasheet.pdf\

Simple test code:

#include <Adafruit_NeoPixel.h>

const int anPin = 4;
const int pirPin = 2;

float detectTime = 150.0;
float leaveTime = 600.0;
float presence = 0.0;
float noPresence = 0.0;

int calibrationTime = 3; 

long anVolt, inches;
int sum=0;
int avgrange=60;

Adafruit_NeoPixel strip = Adafruit_NeoPixel(60, 4, NEO_GRB + NEO_KHZ800);

void setup() {

  //This opens up a serial connection to shoot the results back to the PC console
  Serial.begin(9600);
  
  strip.begin();
  strip.show(); // Initialize all pixels to 'off'
  
  pinMode(pirPin, INPUT);
  digitalWrite(pirPin, LOW);

  //give the sensor some time to calibrate
  Serial.print("calibrating sensor ");
    for(int i = 0; i < calibrationTime; i++){
      Serial.print(".");
      delay(1000);
      }
    Serial.println(" done");
    Serial.println("SENSOR ACTIVE");
    delay(50);
}

void loop() {

  for(int i = 0; i < avgrange ; i++)
  {
    anVolt = analogRead(anPin)/2;
    sum += anVolt;
  }  
  inches = sum/avgrange;

  Serial.println(presence);
  
  if(digitalRead(pirPin) == HIGH && inches <= 10.0){
      presence++;
      noPresence = 0.0;
      if(presence >= detectTime) {
        presence = 0.0;
        colorFill(strip.Color(255, 0, 255));
      }
  }
  
  if(digitalRead(pirPin) == LOW && inches >= 10.0){
    noPresence++;
    presence = 0.0;
    if(noPresence >= leaveTime) {
      noPresence = 0.0;
      colorFill(strip.Color(0, 0, 0));
    }
  }

  //reset sample total
  sum = 0;
}

void colorFill(uint32_t color) {
    for(uint16_t i=0; i<strip.numPixels(); i++) {
      strip.setPixelColor(i, color);
    }
    strip.show();
}