How to Use Gravity I2C Weight Sensor Module: Examples, Pinouts, and Specs

The Gravity I2C Weight Sensor Module by DFRobot is a digital weight sensor designed for precise weight measurement. It utilizes I2C communication for seamless integration with microcontrollers, making it an excellent choice for applications requiring accurate and reliable weight data. This module is commonly used in projects such as digital scales, load monitoring systems, and industrial automation.

With its compact design and user-friendly interface, the Gravity I2C Weight Sensor Module is ideal for both beginners and experienced developers looking to implement weight-sensing capabilities in their projects.

• Manufacturer: DFRobot
• Model: Gravity I2C Weight Sensor Module
• Communication Protocol: I2C
• Operating Voltage: 3.3V to 5V
• Operating Current: ≤ 20mA
• Measurement Range: 0 to 5kg (with included load cell)
• Resolution: 24-bit ADC for high precision
• I2C Address: Default 0x64 (modifiable)
• Dimensions: 32mm x 27mm

The module has a 4-pin interface for I2C communication and power supply. Below is the pinout:

1. Power Supply: Connect the VCC pin to a 3.3V or 5V 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. For an Arduino UNO:
   • SDA connects to A4.
   • SCL connects to A5.
3. Load Cell Connection: Attach the included load cell to the module's dedicated connector.

Below is an example code to interface the Gravity I2C Weight Sensor Module with an Arduino UNO:

#include <Wire.h>

// I2C address of the Gravity I2C Weight Sensor Module
#define WEIGHT_SENSOR_ADDR 0x64

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

  // Initialize the weight sensor
  Serial.println("Initializing Weight Sensor...");
  Wire.beginTransmission(WEIGHT_SENSOR_ADDR);
  if (Wire.endTransmission() == 0) {
    Serial.println("Weight Sensor Initialized Successfully!");
  } else {
    Serial.println("Failed to Initialize Weight Sensor. Check Connections.");
  }
}

void loop() {
  // Request weight data from the sensor
  Wire.beginTransmission(WEIGHT_SENSOR_ADDR);
  Wire.write(0x01); // Command to request weight data
  Wire.endTransmission();

  // Read the weight data
  Wire.requestFrom(WEIGHT_SENSOR_ADDR, 4); // Request 4 bytes of data
  if (Wire.available() == 4) {
    long weight = 0;
    for (int i = 0; i < 4; i++) {
      weight = (weight << 8) | Wire.read(); // Combine bytes into a 32-bit value
    }
    Serial.print("Weight: ");
    Serial.print(weight);
    Serial.println(" g"); // Display weight in grams
  } else {
    Serial.println("Error: No data received from sensor.");
  }

  delay(1000); // Wait 1 second before the next reading
}

• Ensure the load cell is securely mounted and not subject to vibrations or external forces that could affect accuracy.
• Calibrate the sensor before use to ensure precise measurements. Refer to the DFRobot documentation for calibration instructions.
• Avoid exceeding the maximum weight limit of 5kg to prevent damage to the load cell.

1. No Data Received from the Sensor

   • Cause: Incorrect I2C wiring or address mismatch.
   • Solution: Verify the SDA and SCL connections. Ensure the I2C address in the code matches the module's address (default is 0x64).

2. Inaccurate Weight Readings

   • Cause: Improper calibration or unstable load cell mounting.
   • Solution: Recalibrate the sensor and ensure the load cell is securely mounted on a stable surface.

3. Module Not Initializing

   • Cause: Insufficient power supply or damaged module.
   • Solution: Check the power supply voltage (3.3V to 5V). If the issue persists, test with another module.

• Can I use this module with a 3.3V microcontroller?
  Yes, the module supports both 3.3V and 5V logic levels.

• How do I change the I2C address?
  Refer to the DFRobot documentation for instructions on modifying the I2C address using the onboard jumpers.

• What is the maximum cable length for the load cell?
  For optimal performance, keep the load cell cable length under 1 meter to minimize signal degradation.

By following this documentation, you can effectively integrate the Gravity I2C Weight Sensor Module into your projects and achieve accurate weight measurements.