CodeCell: Proximity Sensing

CodeCell includes an onboard VCNL4040 proximity sensor for touchless object detection and depth-based gestures. You can easily read proximity values using the CodeCell library’s built-in function:

uint16_t proximity = myCodeCell.Light_ProximityRead();

This function returns a numerical value representing how close an object is to the sensor. Higher values indicate a closer object. You can use this reading to trigger LEDs, motors, or interactive effects in real-time.

How It Detects Proximity

The VCNL4040 emits infrared light and measures its reflection to estimate distance (up to ~20 cm). It communicates over I²C and is fully handled by the CodeCell Library, allowing you to focus on interaction logic instead of low-level sensor control.

Example 1 – Proximity Trigger

Turns the LED red when an object is close, and green when clear. Adjust the sensitivity using the DISTANCE_RANGE value.

#include <CodeCell.h>

CodeCell myCodeCell;

#define DISTANCE_RANGE 100U  // Proximity trigger threshold (higher = requires closer object)

void setup() {
  Serial.begin(115200);              // Start USB serial at 115200 baud
  myCodeCell.Init(LIGHT);            // Enable light + proximity sensing
  myCodeCell.LED_SetBrightness(0);   // Turn off default LED breathing animation
}

void loop() {
  if (myCodeCell.Run(1)) {           // Run the CodeCell service loop at 1 Hz

    // Read proximity; values above DISTANCE_RANGE mean "object detected / close"
    if (myCodeCell.Light_ProximityRead() > DISTANCE_RANGE) {
      myCodeCell.LED(0xFF, 0x00, 0x00);  // Red: proximity detected
    } else {
      myCodeCell.LED(0x00, 0xFF, 0x00);  // Green: no proximity detected
    }
  }
}

Example 2 – Depth Gestures (Near / Mid / Far)

Maps proximity readings into gesture zones (NEAR, MID, FAR, NONE) and sets LED colors for each state. It also prints live data to the Serial Monitor for debugging or visualization.

#include <CodeCell.h>

CodeCell myCodeCell;

// Thresholds for gesture zones (tweak as needed)
const uint16_t NEAR_THRESHOLD = 700;
const uint16_t MID_THRESHOLD  = 100;
const uint16_t FAR_THRESHOLD  = 10;

void setup() {
  Serial.begin(115200);    // Start USB serial at 115200 baud
  myCodeCell.Init(LIGHT);  // Enable onboard light + proximity sensing

  myCodeCell.LED_SetBrightness(0);  // Turn off default LED breathing animation

  Serial.println(">> Depth Gesture Demo Started");
}

void loop() {
  if (myCodeCell.Run(2)) {  // Run at 2 Hz
    uint16_t proximity = myCodeCell.Light_ProximityRead();

    // Print raw sensor value
    Serial.print("Proximity: ");
    Serial.print(proximity);
    Serial.print("  | Gesture: ");

    // Classify depth gesture
    if (proximity > NEAR_THRESHOLD) {
      Serial.println("NEAR");
      myCodeCell.LED(0xFF, 0x00, 0x00);  // Red LED for near
    } else if (proximity > MID_THRESHOLD) {
      Serial.println("MID");
      myCodeCell.LED(0xFF, 0xA5, 0x00);  // Orange LED for mid
    } else if (proximity > FAR_THRESHOLD) {
      Serial.println("FAR");
      myCodeCell.LED(0x00, 0x00, 0xFF);  // Blue LED for far
    } else {
      Serial.println("NONE");
      myCodeCell.LED(0x00, 0x00, 0x00);  // LED off for no hand
    }
  }
}

Customization Tips

• Tune thresholds: Adjust DISTANCE_RANGE, NEAR_THRESHOLD, MID_THRESHOLD, and FAR_THRESHOLD to fit your setup.
• Change feedback: Swap LED colors or use motors, servos, or buzzers for alternate cues.
• Combine sensors: Pair proximity data with light or IMU readings for gesture-controlled lighting, robots, or smart interfaces.