How to Use Adafruit LTC4316 I2C Address Translator - Stemma QT / Qwiic: Examples, Pinouts, and Specs

The Adafruit LTC4316 (Manufacturer Part ID: 5914) is an I2C address translator designed to resolve address conflicts on I2C buses. It allows multiple I2C devices with identical addresses to coexist on the same bus by dynamically translating their addresses. This component is equipped with Stemma QT / Qwiic connectors, making it easy to integrate into projects without the need for soldering. It is ideal for applications requiring multiple identical sensors or devices on a single I2C bus.

• Connecting multiple I2C devices with the same address to a single bus.
• Prototyping and development of I2C-based systems.
• Expanding the functionality of microcontroller projects using Stemma QT or Qwiic connectors.
• Robotics, IoT, and sensor networks requiring address conflict resolution.

• Operating Voltage: 2.9V to 5.5V
• I2C Bus Speed: Up to 400 kHz (Standard and Fast Mode)
• Address Translation Range: Configurable via ADDR_SEL pin
• Connectors: Stemma QT / Qwiic for plug-and-play integration
• Dimensions: 25.4mm x 17.8mm x 4.6mm (1.0" x 0.7" x 0.18")
• Weight: 1.2g

The Adafruit LTC4316 features the following pins:

1. Power the LTC4316: Connect the VIN pin to a 3.3V or 5V power source and the GND pin to ground.
2. Connect the I2C Bus:
   • Attach the primary I2C bus to the SDA_IN and SCL_IN pins.
   • Connect the secondary I2C bus to the SDA_OUT and SCL_OUT pins.
3. Configure Address Translation:
   • Use the ADDR_SEL pin to set the desired address translation offset. Refer to the datasheet for specific configurations.
4. Enable the Translator:
   • Pull the EN pin high to activate the LTC4316. If left floating, the device may not function correctly.
5. Optional Stemma QT / Qwiic Connection:
   • Use the onboard connectors for plug-and-play integration with compatible devices.

• Ensure that the I2C bus speed does not exceed 400 kHz.
• Avoid leaving the ADDR_SEL pin floating; always configure it properly.
• Use pull-up resistors on the I2C lines if they are not already present in your circuit.
• Verify that the power supply voltage is within the specified range (2.9V to 5.5V).
• For Arduino projects, ensure the Wire library is included and properly configured.

Below is an example of how to use the LTC4316 with an Arduino UNO to translate the address of an I2C device:

#include <Wire.h> // Include the Wire library for I2C communication

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

  // Check if the I2C device is detected at the translated address
  Wire.beginTransmission(0x72); // Replace 0x72 with the translated address
  if (Wire.endTransmission() == 0) {
    Serial.println("I2C device detected at translated address!");
  } else {
    Serial.println("No device found at translated address.");
  }
}

void loop() {
  // Add your main code here
}

1. No Communication with the I2C Device:

   • Ensure the EN pin is pulled high to enable the LTC4316.
   • Verify that the ADDR_SEL pin is configured correctly for the desired address translation.
   • Check the wiring of the I2C bus and ensure proper connections to SDA_IN, SCL_IN, SDA_OUT, and SCL_OUT.

2. I2C Bus Not Functioning:

   • Confirm that pull-up resistors are present on the I2C lines if required.
   • Ensure the bus speed does not exceed 400 kHz.

3. Device Not Detected at Translated Address:

   • Double-check the translated address configuration using the ADDR_SEL pin.
   • Verify that the primary device is functioning correctly and is accessible at its original address.

• Can I use the LTC4316 with 5V and 3.3V devices on the same bus? Yes, the LTC4316 supports mixed-voltage systems as long as the voltage levels are within the specified range.

• What happens if the ADDR_SEL pin is left floating? Leaving the ADDR_SEL pin floating may result in undefined behavior. Always configure it properly.

• Can I use multiple LTC4316 modules on the same bus? Yes, multiple LTC4316 modules can be used, but ensure that each module's ADDR_SEL pin is configured uniquely to avoid conflicts.

This documentation provides a comprehensive guide to using the Adafruit LTC4316 I2C Address Translator. For additional details, refer to the official datasheet or Adafruit's product page.