QT USB BITBANG Mode example for Android using FTDI D2XX driver

This is a QT example for using the FTDI D2xx driver (j2xx.jar) on Android devices. It just can send a value on “Channel A” and receive a value on “Channel B” via the FT2232H chipset.

Overview

Just connect your FTDI Chip with an USB OTG adapter to your Android device. To test the application, connect the Channel A and Channel B (see table) with a jumper cable.

Signal Channel A	FT2232H pin	Signal Channel A	FT2232H pin
D0	2	D0	38
D1	3	D1	39
D2	6	D2	40
D3	9	D3	41
D4	1	D4	42
D5	5	D5	43
D6	10	D6	44
D7	11	D7	45

Some information about the code

I wrote two classes. The QT Class MainWindow and the JAVA Class MyFTDIClass.

I have encapsulated the control of the FTDI driver (j2xx.jar) in its own JAVA class (MyFTDIClass), this has the advantage that I don't have to pass the objects D2xxManager and FT_Device to my MainWindow class via JNI. I only provide the Init, Read and Write methods, which I can easily call using the "QAndroidJniObject::callStaticMethod" Method.

AndroidManifest.xml

Changes to the Manifest file

<activity
 android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation"
	 android:name="org.usbexample.ftdi.MyFTDIClass"
	 android:label="-- %%INSERT_APP_NAME%% --"
	 android:screenOrientation="unspecified"
	 android:launchMode="singleTop">



<uses-feature android:name="android.hardware.usb.host"/>
    <intent-filter>
      <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED"/>
    </intent-filter>
    <meta-data android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" android:resource="@xml/device_filter"/>

You have to change the android:name to

android:name="org.usbexample.ftdi.MyFTDIClass"

QT Projekt File

For using the QAndroidJniObject, you have to add androidextras:

QT += core gui androidextras

in your project file (usbexample.pro)