[](https://github.com/mik3y/usb-serial-for-android/actions)
[](https://jitpack.io/#mik3y/usb-serial-for-android)
[](https://app.codacy.com/gh/kai-morich/usb-serial-for-android-mik3y/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade)
[](https://codecov.io/gh/mik3y/usb-serial-for-android)
# usb-serial-for-android
This is a driver library for communication with Arduinos and other USB serial hardware on
Android, using the
[Android USB Host Mode (OTG)](http://developer.android.com/guide/topics/connectivity/usb/host.html)
available since Android 3.1 and working reliably since Android 4.2.
No root access, ADK, or special kernel drivers are required; all drivers are implemented in
Java. You get a raw serial port with `read()`, `write()`, and [other functions](https://github.com/mik3y/usb-serial-for-android/wiki/FAQ#Feature_Matrix) for use with your own protocols.
## Quick Start
**1.** Add library to your project:
Add jitpack.io repository to your root build.gradle:
```gradle
allprojects {
repositories {
...
maven { url 'https://jitpack.io' }
}
}
```
Starting with gradle 6.8 you can alternatively add jitpack.io repository to your settings.gradle:
```gradle
dependencyResolutionManagement {
repositories {
...
maven { url 'https://jitpack.io' }
}
}
```
If using gradle kotlin use line
```gradle.kts
maven(url = "https://jitpack.io")
```
Add library to dependencies
```gradle
dependencies {
implementation 'com.github.mik3y:usb-serial-for-android:3.7.0'
}
```
**2.** If the app should be notified when a device is attached, add
[device_filter.xml](https://github.com/mik3y/usb-serial-for-android/blob/master/usbSerialExamples/src/main/res/xml/device_filter.xml)
to your project's `res/xml/` directory and configure in your `AndroidManifest.xml`.
```xml
```
**3.** Use it! Example code snippet:
open device:
```java
// Find all available drivers from attached devices.
UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
List availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(manager);
if (availableDrivers.isEmpty()) {
return;
}
// Open a connection to the first available driver.
UsbSerialDriver driver = availableDrivers.get(0);
UsbDeviceConnection connection = manager.openDevice(driver.getDevice());
if (connection == null) {
// add UsbManager.requestPermission(driver.getDevice(), ..) handling here
return;
}
UsbSerialPort port = driver.getPorts().get(0); // Most devices have just one port (port 0)
port.open(connection);
port.setParameters(115200, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE);
```
then use direct read/write
```java
port.write(request, WRITE_WAIT_MILLIS);
len = port.read(response, READ_WAIT_MILLIS);
```
or direct write + event driven read:
```java
usbIoManager = new SerialInputOutputManager(usbSerialPort, this);
usbIoManager.start();
...
port.write("hello".getBytes(), WRITE_WAIT_MILLIS);
@Override
public void onNewData(byte[] data) {
runOnUiThread(() -> { textView.append(new String(data)); });
}
```
and finally:
```java
port.close();
```
For a simple example, see
[UsbSerialExamples](https://github.com/mik3y/usb-serial-for-android/blob/master/usbSerialExamples)
folder in this project.
For a more complete example with background service to stay connected while
the app is not visible or rotating, see separate github project
[SimpleUsbTerminal](https://github.com/kai-morich/SimpleUsbTerminal).
## Probing for Unrecognized Devices
Sometimes you may need to do a little extra work to support devices which
usb-serial-for-android doesn't (yet) know about -- but which you know to be
compatible with one of the built-in drivers. This may be the case for a brand
new device or for one using a custom VID/PID pair.
UsbSerialProber is a class to help you find and instantiate compatible
UsbSerialDrivers from the tree of connected UsbDevices. Normally, you will use
the default prober returned by ``UsbSerialProber.getDefaultProber()``, which
uses USB interface types and the built-in list of well-known VIDs and PIDs that
are supported by our drivers.
To use your own set of rules, create and use a custom prober:
```java
// Probe for our custom FTDI device, which use VID 0x1234 and PID 0x0001 and 0x0002.
ProbeTable customTable = new ProbeTable();
customTable.addProduct(0x1234, 0x0001, FtdiSerialDriver.class);
customTable.addProduct(0x1234, 0x0002, FtdiSerialDriver.class);
UsbSerialProber prober = new UsbSerialProber(customTable);
List drivers = prober.findAllDrivers(usbManager);
// ...
```
*Note*: as of v3.5.0 this library detects CDC devices by USB interface types instead of fixed VID+PID,
so custom probers are typically not required any more for CDC devices.
Of course, nothing requires you to use UsbSerialProber at all: you can
instantiate driver classes directly if you know what you're doing; just supply
a compatible UsbDevice.
## Compatible Devices
This library supports USB to serial converter chips:
* FTDI FT232R, FT232H, FT2232H, FT4232H, FT230X, FT231X, FT234XD
* Prolific PL2303
* Silabs CP2102, CP210*
* Qinheng CH340, CH341A, CH9102
devices implementing the CDC/ACM protocol like
* Arduino using ATmega32U4
* Digispark using V-USB software USB
* BBC micro:bit using ARM mbed DAPLink firmware
* ...
and some device specific drivers:
* GsmModem devices, e.g. for Unisoc based Fibocom GSM modems
* Chrome OS CCD (Closed Case Debugging)
## Help & Discussion
For common problems, see the [FAQ](https://github.com/mik3y/usb-serial-for-android/wiki/FAQ) wiki page.
Are you using the library? Add your project to
[ProjectsUsingUsbSerialForAndroid](https://github.com/mik3y/usb-serial-for-android/wiki/Projects-Using-usb-serial-for-android).