Develop Reference

Unable to send keyboard events to Bluetooth HID connected device

I am able to connect to the Bluetooth HID device successfully and able to control the paired device home button and navigation buttons.
But unable to send Keyboard key events properly to the HID device. When I am typing something in the host device, the HID device responding with random actions.
I have the following code for the connection with descriptors array,
override fun onServiceConnected(profile: Int, proxy: BluetoothProfile?) {
if (profile == BluetoothProfile.HID_DEVICE) {
mBtHidDevice = proxy as BluetoothHidDevice
val sdp = BluetoothHidDeviceAppSdpSettings(
"HidControl",
"Android HID Joystick",
"Android",
0xC0.toByte(),
descriptor
)
}
}
The descriptor array is as below,
private val descriptor = byteArrayOf( // HID descriptor
0x09, // bLength
0x21, // bDescriptorType - HID
0x11, 0x01, // bcdHID (little endian - 1.11)
0x00, // bCountryCode
0x01, // bNumDescriptors (min 1)
0x22, // bDescriptorType - Report
0x30, 0x00, // wDescriptorLength (48)
// Report descriptor
0x05, 0x01, // USAGE_PAGE (Generic Desktop)
0x09, 0x06, // USAGE (Key board)
0xa1.toByte(), 0x01, // COLLECTION (Application)
0xa1.toByte(), 0x00, // COLLECTION (Physical)
0x05, 0x09, // USAGE_PAGE (Button)
0x19, 0x01, // USAGE_MINIMUM (Button 1)
0x29, 0x04, // USAGE_MAXIMUM (Button 4)
0x15, 0x00, // LOGICAL_MINIMUM (0)
0x25, 0x01, // LOGICAL_MAXIMUM (1)
0x75, 0x01, // REPORT_SIZE (1)
0x95.toByte(), 0x04, // REPORT_COUNT (4)
0x81.toByte(), 0x02, // INPUT (Data,Var,Abs)
0x75, 0x04, // REPORT_SIZE (4)
0x95.toByte(), 0x01, // REPORT_COUNT (1)
0x81.toByte(), 0x03, // INPUT (Cnst,Var,Abs)
0x05, 0x01, // USAGE_PAGE (Generic Desktop)
0x09, 0x30, // USAGE (X)
0x09, 0x31, // USAGE (Y)
0x15, 0x81.toByte(), // LOGICAL_MINIMUM (-127)
0x25, 0x7f, // LOGICAL_MAXIMUM (127)
0x75, 0x08, // REPORT_SIZE (8)
0x95.toByte(), 0x02, // REPORT_COUNT (2)
0x81.toByte(), 0x02, // INPUT (Data,Var,Abs)
0xc0.toByte(), // END_COLLECTION
0xc0.toByte() // END_COLLECTION
)
Code to send keyboard events to the target device is below
override fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
Log.d("Key Codes ", "$keyCode + event: $event")
for (btDev in mBtHidDevice!!.connectedDevices) {
mBtHidDevice!!.sendReport(
btDev, 0, byteArrayOf(event!!.keyCode.toByte())
)
mBtHidDevice!!.sendReport(
btDev, 0, byteArrayOf(
0
)
)
}
return super.onKeyUp(keyCode, event)
}
Please suggest if I am missing anything here. Thanks for the help!

You need to use Keyboard Usage Page.
The logical minimum and logical maximum that I see is only from 1 to 4. You wanted those USAGEs alone?
Refer to HID usage table https://www.usb.org/document-library/hid-usage-tables-122
There is a Keyboard use case in the appendix. You can refer to that.

NFC Apdu Response 67 00 (wrong length) on Android using isodep

i tried to send extended APDU command into Desfire card on Android.
i was select the application on the card and success.
but when i tried to authentication process and send this command, i got response 67 00 (wrong length)
i send data :
00820000288C9D8E3837E8E47514E9010801C1615E65E677A21DC40E07B32DF6DE24EED3D6CD950BA8CB5E738528
where:
CLA : 0x00
INS : 0x82
P1 : 0x00
P2 : 0x00
Lc : 0x28 //(40 bytes)
data :
0x8C, 0x9D, 0x8E, 0x38, 0x37, 0xE8, 0xE4, 0x75, 0x14, 0xE9, 0x01, 0x08, 0x01, 0xC1
, 0x61, 0x5E, 0x65, 0xE6, 0x77, 0xA2, 0x1D, 0xC4, 0x0E, 0x07, 0xB3, 0x2D, 0xF6, 0xDE
, 0x24, 0xEE, 0xD3, 0xD6, 0xCD, 0x95, 0x0B, 0xA8, 0xCB, 0x5E, 0x73, 0x85
**Le : 0x28 (expected return length)**
i think there is nothing wrong with the command structure, but why the response is 67 00
i am using isodep library.
please some one help me..

What is / how do I find the universal ibeacon identifier?

I am trying to write an android application to interface with iBeacons, but I need to find the start of the UUID / major / minor characteristics in the byte array. Through look at a couple of resources including this question, it seems like ALL iBeacons transmit some pattern in the byte array that is the same that identifies them as iBeacons.
I asked another question recently and got a useful answer, link here but 1) I haven't been able to test it's functionality (waiting on my device) and 2) I want to know how it is working.
So my questions: What is that pattern? Can I find it just by searching that array for the pattern? And is the UUID / Major / Minor always a predefined number of spots in the array from that identifying pattern?
Thanks!

So after looking around on a few different sites, I have found that 3 people list their patterns as
02 01 06 1A FF 4C 00 02 15
or
02 01 1A 1A FF 4C 00 02 15
which isn't super helpful, since the 4C 00 appears to just be the Apple identifier, which I'm assuming could switch based on the manufacturer (Estimote, GE, Apple, whatever). However, it appears that the
02 15
is static, so I'm using that. My solution for finding it basically is just searching the byte array that I get for the first occurrence of that sequence of 2 bytes, and starting right after that I grab the next 16 as the UUID, the next 2 after that as the Major, and the next 2 after that as the Minor. So to clarify with code:
//adPacket is an array I created to represent an iBeacon ad for testing
byte[] adPacket = {(byte) 0xd6, (byte) 0xbe, (byte) 0x89, (byte) 0x8e, 0x40, 0x24, 0x05, (byte) 0xa2,
0x17, 0x6e, 0x3d, 0x71, 0x02, 0x01, 0x06, 0x1A, (byte) 0xFF, 0x4C, 0x00, 0x02, 0x15, (byte) 0xe2,
(byte) 0xc5, 0x6d, (byte) 0xb5, (byte) 0xdf, (byte) 0xfb, 0x48, (byte) 0xd2, (byte) 0xb0, 0x60, (byte) 0xd0,
(byte) 0xf5, (byte) 0xa7, 0x10, (byte) 0x96, (byte) 0xe0, 0x00, 0x00, 0x00, 0x00, (byte) 0xc5, 0x52, (byte) 0xab, (byte) 0x8d, 0x38, (byte) 0xa5};
byte[] pattern = {0x02, 0x15};
int startIndex = findAdPacketEnd(adPacket, pattern) + 1;
if(startIndex == 0){ System.out.println("Pattern not found"); return;}
int endIndex = startIndex + 21;
ArrayList<Byte> tempArray = new ArrayList<Byte>();
for(int i = startIndex; i<endIndex; i++){
tempArray.add(adPacket[i]);
}
byte[] proxUUID = new byte[16];
for(int i = 0; i<16; i++){
proxUUID[i] = tempArray.get(i);
}
byte[] major = new byte[2];
major[0] = tempArray.get(16);
major[1] = tempArray.get(17);
byte[] minor = new byte[2];
minor[0] = tempArray.get(18);
minor[1] = tempArray.get(19);
...
where my findAdPacketEnd function is (not the most efficient but it works):
private static int findAdPacketEnd(byte[] adPacket, byte[] pattern){
//return -1 if pattern is too long
if(adPacket.length < pattern.length)
return -1;
//iterate over adPacket
for(int i = 0; i<adPacket.length - pattern.length; i++){
System.out.println("Searching Ad Packet");
//iterate over pattern
for(int j = 0; j<pattern.length; j++){
//compare wherever you are in the adpacket to the pattern, break if it doesn't match
if(adPacket[i+j] != pattern[j])
break;
// if you get to the end of the pattern and there wasn't a mismatch, return the index
if(j == pattern.length-1)
return i+pattern.length-1;
}
}
//pattern not found
return -1;
}

Wifi printer not printing the pages android

I have using the following code:
Socket client = new Socket(etIp.getText().toString(), 515);
String printText = "This is a print test from Wifi";
byte[] mybytearray = printText.getBytes();
OutputStream outputStream = client.getOutputStream();
outputStream.write(mybytearray, 0, mybytearray.length); //write file to the output stream byte by byte
outputStream.flush();
outputStream.close();
client.close();
Socket connection opened, and no exception while complete process of write data in output stream. But printer not eject the page.
Please help me what I have did wrong.

I think you need to send few more data for it to eject and let the printer know.
For Epson L355 I am appending a byte array at the end of my string.
byte[] EjectByteArray = {0X00, 0X0D, 0X0C, 0X1B, 0X40, 0X1B, 0X28, 0X52, 0X08, 0X00, 0X00, 0X52, 0X45, 0X4D, 0X4F, 0X54, 0X45, 0X31, 0X4C, 0X44, 0X00, 0X00, 0X1B, 0X00, 0X00, 0X00, 0X1B, 0X40, 0X1B, 0X28, 0X52, 0X08, 0X00, 0X00, 0X52, 0X45, 0X4D, 0X4F, 0X54, 0X45, 0X31, 0X4C, 0X44, 0X00, 0X00, 0X4A, 0X45, 0X01, 0X00, 0X00, 0X1B, 0X00, 0X00, 0X00};
You may need to run a Port sniffer and try to capture the last byte array being passed after a print is finished. It would give you a clue on how you should send an eject command. This is one works on me using port 9100 on Epson L355
outputStream.write(mybytearray, 0, mybytearray.length);
outputStream.write(EjectByteArray, 0, EjectByteArray.length);
outputStream.flush();
outputStream.close();
client.close();

Add \n end of the line.this is work for me
String printText = "Finally its working \n";

NFC Smartposter to Dial a number

i want to create a NFC SmartPoster which dial a number with Action Record type "act".
Can anyone tell how to get Action Record type "act" in android from packet and check whether packet contains Action Record type "act" or not.
Below is packet i have created.
/**
* Smart Poster containing a Telephone number and Action record type.
*/
public static final byte[] SMART_POSTER_Dial_Number =
new byte[] {
// SP type record
(byte) 0xd1, (byte) 0x02, (byte) 0x26, (byte) 0x53, (byte) 0x70,
// Call type record
(byte) 0xd1, (byte) 0x01, (byte) 0x0e, (byte) 0x55, (byte) 0x05, (byte) 0x2b,
(byte) 0x39, (byte) 0x31, (byte) 0x38, (byte) 0x38, (byte) 0x37, (byte) 0x32,
(byte) 0x37, (byte) 0x34, (byte) 0x33, (byte) 0x39, (byte) 0x33, (byte) 0x39,
// Action type record
(byte) 0x11, (byte) 0x03, (byte) 0x01, (byte) 0x61, (byte) 0x63, (byte) 0x74,
(byte) 0x00,
// Text type record with 'T'
(byte) 0x91, (byte) 0x01, (byte) 0x09, (byte) 0x54, (byte) 0x02, (byte) 'C',
(byte) 'a', (byte) 'l', (byte) 'l', (byte) 'i', (byte) 'n', (byte) 'g', (byte) '.'
};
Please help..

When you receive an NDEF message in your Activity via an ACTION_NDEF_DISCOVERED intent, you can parse and check the contents for a SmartPoster record with an embedded 'act' record as follows:
Intent intent = getIntent();
final Parcelable[] rawMsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES);
NdefMessage mesg = (NdefMessage) rawMsgs[0]; // in theory there can be more messages
// let's inspect the first record only
NdefRecord[] record = mesg.getRecords()[0];
byte[] type = record.getType();
// check if it is a SmartPoster
byte[] smartPoster = { 'S', 'p'};
if (Arrays.equals(smartPoster, type) {
byte[] payload = record.getPayload();
// try to parse the payload as NDEF message
NdefMessage n;
try {
n = new NdefMessage(payload);
} catch (FormatException e) {
return; // not an NDEF message, we're done
}
// try to find the 'act' record
NdefRecord[] recs = n.getRecords();
byte[] act = { 'a', 'c', 't' };
for (NdefRecord r : recs) {
if (Arrays.equals(act, r.getType()) {
... // found it; do your thing!
return;
}
}
}
return; // nothing found
BTW: You will find that there are a couple of format errors in the example message in your question: the first byte of the Uri record should be 0x81 and the first byte of the Text record should be 0x51.