How to Use Time of flight sensor: Examples, Pinouts, and Specs

The VL53L5CX is a state-of-the-art Time of Flight (ToF) sensor manufactured by STM Electronics. It measures the distance to an object by calculating the time it takes for a light signal to travel to the object and return. This sensor is capable of multi-zone distance measurement, making it ideal for applications requiring precise depth sensing and spatial awareness.

• Robotics and obstacle detection
• Gesture recognition
• Autonomous vehicles and drones
• Smart home devices (e.g., presence detection)
• Industrial automation and safety systems
• Augmented reality (AR) and virtual reality (VR) applications

The VL53L5CX is a highly versatile sensor with the following key specifications:

The VL53L5CX has the following pinout:

1. Power Supply: Connect the VIN pin to a 2.8 V power source and the GND pin to ground.
2. I²C Communication: Connect the SDA and SCL pins to the corresponding I²C pins on your microcontroller. Use pull-up resistors (typically 4.7 kΩ) on both lines.
3. Interrupts (Optional): If needed, connect GPIO1 to a microcontroller pin to handle interrupts for events like measurement completion.
4. Bypass Capacitors: Place a 100 nF capacitor close to the VIN and GND pins to stabilize the power supply.

• Ambient Light: Avoid placing the sensor in direct sunlight or near strong light sources, as this can affect measurement accuracy.
• Reflective Surfaces: Highly reflective or transparent surfaces may cause inaccurate readings. Test the sensor in your specific environment.
• I²C Address: The default I²C address of the VL53L5CX is 0x52. Ensure no other devices on the I²C bus share this address.
• Mounting: Ensure the sensor's field of view is unobstructed for optimal performance.

Below is an example of how to interface the VL53L5CX with an Arduino UNO using the I²C protocol:

#include <Wire.h>
#include <VL53L5CX.h> // Include the VL53L5CX library

VL53L5CX sensor; // Create a sensor object

void setup() {
  Serial.begin(9600); // Initialize serial communication
  Wire.begin();       // Initialize I²C communication

  // Initialize the VL53L5CX sensor
  if (!sensor.begin()) {
    Serial.println("Failed to initialize VL53L5CX sensor!");
    while (1); // Halt execution if initialization fails
  }

  Serial.println("VL53L5CX initialized successfully!");
}

void loop() {
  uint16_t distance; // Variable to store measured distance

  // Perform a distance measurement
  if (sensor.getDistance(&distance)) {
    Serial.print("Distance: ");
    Serial.print(distance);
    Serial.println(" mm");
  } else {
    Serial.println("Failed to read distance!");
  }

  delay(500); // Wait 500 ms before the next measurement
}

• Install the VL53L5CX library in your Arduino IDE before running the code.
• Adjust the delay() value in the loop to control the measurement frequency.

1. Sensor Not Detected on I²C Bus

   • Ensure the SDA and SCL lines are correctly connected to the microcontroller.
   • Verify that pull-up resistors are present on the I²C lines.
   • Check the sensor's power supply voltage (2.8 V typical).

2. Inaccurate Distance Measurements

   • Avoid using the sensor in environments with excessive ambient light.
   • Ensure the target object is within the sensor's measurement range (0.1 m to 4 m).
   • Clean the sensor's lens to remove dust or smudges.

3. Intermittent Readings

   • Verify that the power supply is stable and free of noise.
   • Check for loose connections in the circuit.

Q: Can the VL53L5CX measure multiple distances simultaneously?
A: Yes, the VL53L5CX supports multi-zone measurements, allowing it to measure distances in up to 64 zones (8x8 grid).

Q: What is the maximum I²C clock speed supported by the VL53L5CX?
A: The VL53L5CX supports I²C clock speeds of up to 1 MHz.

Q: Can the sensor operate in outdoor environments?
A: While the VL53L5CX can operate outdoors, its performance may be affected by direct sunlight or extreme temperatures. Use appropriate shielding or enclosures for outdoor applications.

Q: Is the VL53L5CX compatible with 5 V microcontrollers?
A: The VL53L5CX operates at 2.8 V. Use a level shifter to interface it with 5 V microcontrollers.

By following this documentation, users can effectively integrate the VL53L5CX Time of Flight sensor into their projects and troubleshoot common issues.