usb-i2c-android

This is a library for communication with I²C devices on Android using USB I²C adapters connected to the Android USB Host (OTG). No root access or special kernel drivers are required.

Supported adapters

• I2C-Tiny-USB
• Silicon Labs CP2112
• Qinheng Microelectronics CH341
• Future Technology Devices International FT232H

Usage

Add jitpack.io repository to your root build.gradle:

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

Add library to dependencies:

dependencies {
    implementation 'com.github.3cky:usb-i2c-android:1.3.1'
}

Add USB host feature usage to your app manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="...">
    <uses-feature android:name="android.hardware.usb.host" />
    ...
</manifest>

Example code:

import com.github.ykc3.android.usbi2c.UsbI2cAdapter;
import com.github.ykc3.android.usbi2c.UsbI2cDevice;
import com.github.ykc3.android.usbi2c.UsbI2cManager;
...

// Get Android UsbManager
UsbManager usbManager = (UsbManager) getSystemService(Context.USB_SERVICE);

// Find all connected I²C adapters
UsbI2cManager usbI2cManager = UsbI2cManager.create(usbManager).build();
List<UsbI2cAdapter> i2cAdapters = usbI2cManager.getAdapters();
if (i2cAdapters.isEmpty()) {
    return;
}

// Get first adapter
UsbI2cAdapter i2cAdapter = i2cAdapters.get(0);

// Request USB access permission
usbManager.requestPermission(i2cAdapter.getUsbDevice(), usbPermissionIntent);
...
// USB permission intent handler called with success result

// Set bus clock speed to 400 kbit/s, if supported by adapter 
if (i2cAdapter.isClockSpeedSupported(UsbI2cAdapter.CLOCK_SPEED_FAST)) {
    i2cAdapter.setClockSpeed(UsbI2cAdapter.CLOCK_SPEED_FAST);
}

// Open adapter
i2cAdapter.open();

// Get device with I²C address 0x42
UsbI2cDevice i2cDevice = i2cAdapter.getDevice(0x42);

// Read device register 0x01.
// Throws java.lang.IOException if device is not connected or I/O error caused 
byte value = i2cDevice.readRegByte(0x01);

// Close adapter
i2cAdapter.close();

Sample app

For simple I²C device scanner sample app, check an app module.

License

This library is licensed under LGPL Version 2.1. Please see LICENSE.txt for the complete license.