Arduino PhotoCell Array Averaged Library

Overview

A full Arduino library for managing an array of photocell (light-dependent resistor) sensors. Each sensor in the array maintains an independent sliding-window moving average, making readings stable and noise-resistant.

Features

• Array of sensors — manage multiple LDRs with a single object
• Sliding-window moving average — configurable window size per sensor smooths out noise
• Threshold detection — each sensor reports a binary above/below-threshold status
• Pin pair wiring — each sensor uses a signal pin and a ground pin (no shared ground resistor needed — the Arduino drives the ground pin LOW)
• Dynamic allocation — sensor array size set at construction, proper destructor

Usage

#include "PhotCellArrayAveraged.h"

// 4 sensors, each averaged over 10 samples
PhotoCell ldr[] = {
  {Pins{A0, A1}, 10},
  {Pins{A2, A3}, 10},
  {Pins{A4, A5}, 10},
  {Pins{A6, A7}, 10}
};

void loop() {
  for (int i = 0; i < 4; i++) {
    ldr[i].update();
    Serial.print(ldr[i].average());
    Serial.print("(");
    Serial.print(ldr[i].thresholdStatus());
    Serial.print(") ");
  }
  Serial.println();
  delay(1000);
}

Wiring

Each sensor uses two analog pins — one driven LOW as a virtual ground, one read as the signal. This avoids needing a resistor to ground on each sensor and makes wiring a large array cleaner.

Pin Pair Approach

Driving the ground pin LOW from the Arduino instead of using a shared PCB ground trace means each sensor is fully self-contained on two adjacent analog pins. No breadboard jumpers or separate resistors — just the photocell and a resistor between two pins.