@transmission-dynamics/i2c-transfer

I2C Transfer Module

A simple Node.js module for performing I2C transfers using N-API.

Installation

npm install @transmission-dynamics/i2c-transfer

Usage

const { i2cTransfer } = require('@transmission-dynamics/i2c-transfer');

(async () => {
  try {
    const bus = '/dev/i2c-1'; // I2C bus device path
    const addr = 0x54;        // I2C slave device address
    const writeBuffer = new Uint8Array([0x04]); // Data to write
    const readSize = 3;       // Number of bytes to read

    const readBuffer = await i2cTransfer(bus, addr, writeBuffer, readSize);

    console.log('Data read from I2C device:', readBuffer);
  } catch (err) {
    console.error('Error:', err.message);
  }
})();

Description

The i2cTransfer function allows you to perform an I2C write followed by a read operation asynchronously. It communicates with I2C devices by writing data to a specified register or command and then reading the response.

Parameters

• bus (string): The I2C bus device path (e.g., '/dev/i2c-1').
• addr (number): The I2C slave device address (7-bit address).
• writeBuffer (Buffer or Uint8Array): The data to write to the I2C device.
• readSize (number): The number of bytes to read from the I2C device.

Returns

• A Promise that resolves with a Buffer containing the data read from the I2C device.

Notes

• Permissions: Ensure your user has the necessary permissions to access the I2C bus device (e.g., /dev/i2c-1). You may need to run your script with elevated privileges or adjust the device permissions.
• Error Handling: The function throws errors if any I2C operation fails. Use try-catch blocks to handle exceptions.
• Asynchronous Operation: The i2cTransfer function is asynchronous and returns a Promise, allowing you to use async/await syntax.

License

This project is licensed under the MIT License.

Changelog

3.0.0

• In case of error reject with Error instead of string.