Question

我正在使用Android USB Host API使用FT232发送和接收数据。我使用两个线程作为发送部分和读取部分。我可以发送和接收数据，但读取的数据不等于数据发送的数据。例如，当我发送字节[1,2,3,4,5]时。读取的数据有时是字节[1,2,5]。有时可以读取5个字节，但有时会丢失一些字节。附上我正在使用的代码。

设置部分：

HashMap<String, UsbDevice> list = mUsbManager.getDeviceList();
Iterator<UsbDevice> iterator = list.values().iterator();
while(iterator.hasNext()) {
    UsbDevice device = iterator.next();
    if (device.getInterfaceCount() == 1) {
        mInterface = device.getInterface(0);
        for (int i = 0; i < mInterface.getEndpointCount(); i++) {
            if (mInterface.getEndpoint(i).getType() == UsbConstants.USB_ENDPOINT_XFER_BULK) {
                if (mInterface.getEndpoint(i).getDirection() == UsbConstants.USB_DIR_IN) {
                    mEndpointIn = mInterface.getEndpoint(i);
                } else {
                    mEndpointOut = mInterface.getEndpoint(i);
                }
             }
                            }
                    }
                }
            }
        }

发送部分：

UsbDeviceConnection connection = mUsbManager.openDevice(device);
if (connection == null) {
    Log.e(TAG, "Connection terminated");
    return;
}
byte[] bytes = new byte[1, 2, 3, 4, 5];
boolean claimed = connection.claimInterface(mInterface, true);
if (claimed) {
    connection.controlTransfer(0x40, 0x03, 0x0034, 0, null, 0, 0); // baud rate 57600
    connection.controlTransfer(0x40, 0x04, 0x0008, 0, null, 0, 0); // 8-N-1
    int sentLength = connection.bulkTransfer(mEndpointOut, bytes, bytes.length, 100);
    connection.releaseInterface(mInterface);
    connection.close();
}

阅读部分：

UsbDeviceConnection connection = mUsbManager.openDevice(device);
if (connection == null) {
    Log.e(TAG, "Connection terminated");
    return;
}
byte[] inData = new byte[64];
boolean claimed = connection.claimInterface(mInterface, true);
if (claimed) {
    connection.controlTransfer(0x40, 0x03, 0x0034, 0, null, 0, 0); // baud rate 57600
    connection.controlTransfer(0x40, 0x04, 0x0008, 0, null, 0, 0); // 8-N-1
    int readLength = connection.bulkTransfer(mEndpointIn, inData, inData.length, 100);
    connection.releaseInterface(mInterface);
    connection.close();
    // 'result' is the data I want, the first 2 bytes are status bytes so being removed
    byte[] result = new byte[inData.length - 2];
    System.arrayCopy(inData, 2, result, 0, inData.length - 2);
}

Answer 1

我找到了一个解决这个问题的Android库。希望它能帮助任何有同样问题的人。

UsbSerial

Android USB无法通过bulkTransfer读取完整数据

1 个答案: