CodeCell: Proximity Sensing

In this build, we'll explore how to use the CodeCell's onboard proximity sensor to detect objects.

What You'll Learn

How to set up the CodeCell
How to write code to read proximity data and control onboard LED.
An understanding of how the CodeCell's VCNL4040 proximity sensor works.

About the CodeCell's Proximity Sensor

The CodeCell is equipped with a VCNL4040 sensor that can measure proximity up to 20 cm. This sensor uses I2C communication and is automatically initialized through the CodeCell library, allowing for seamless integration into your projects. Whether you're looking to add simple gesture depth control or detect nearby objects, the VCNL4040 makes it easy to add proximity sensing into your builds.

How Proximity Sensing Works

The VCNL4040 proximity sensor uses infrared light to detect objects within its range. It measures the reflection of emitted IR light to approximate how close an object is, allowing you to create responsive behaviors based on proximity. This feature is particularly useful for creating interactive lighting, robotics, touchless switches, or other proximity-based actions.

Project Overview

In this example, the CodeCell continuously monitors proximity data and turns on a red LED when an object is detected. You can expand on this basic functionality to create more complex interactions, such as varying the LED color or brightness based on distance, or triggering different actions based on proximity.

Code Example

Below is the example code to get you started. Ensure your CodeCell is properly connected via USB-C, and follow the comments in the code to understand each step.


#include <CodeCell.h>

CodeCell myCodeCell;

void setup() {
    Serial.begin(115200); // Set Serial baud rate to 115200. Ensure Tools/USB_CDC_On_Boot is enabled if using Serial
    myCodeCell.Init(LIGHT); // Initializes light sensing, including proximity
}

void loop() {
    if (myCodeCell.Run()) {
        // Runs every 100ms to check proximity
        uint16_t proximity = myCodeCell.Light_ProximityRead();
        
        // Check if an object is within range
        if (proximity > 100) {
            myCodeCell.LED(0xFF, 0, 0); // Set LED to Red when proximity is detected
            delay(1000); // Keep the LED on for 1 second
        } else {
            // No action if the object is out of range
        }
    }
}

Tips for Customization

Adjust Proximity Threshold: Modify the threshold value (100 in the example) to adjust the sensitivity of proximity detection based on your application.
Change LED Colors: Experiment with different LED colors using the myCodeCell.LED() function to create multi-colored responses to proximity.
Add More: Consider adding a buzzer or motor to provide audio or motion feedback when objects are detected within range.
Use Proximity with Light Sensing: Combine proximity and light sensing to create more complex behaviors, such as adjusting lights based on both distance and ambient light levels.

Conclusion

This project introduces the basics of using proximity sensing with CodeCell, opening up a range of interactive possibilities. Experiment with the code, tweak the settings, and make it your own!

Click here for the next example, where we will experiment with using this proximity sensor for depth gestures.