I need help with this project, i use BLE and connect it to smartphone and i can get the RSSI value by "ScanResult" in the ScannerFragment but its a static value in the recyclerview, i dont know what to do to make the RSSI value change in real time as i move my phone away/ closer to the BLE device, so it would jump for example from -50dBm to -60dBm as i move the smartphone away from the BLE device
ScannerFragment
import android.Manifest
import android.app.AlertDialog
import android.bluetooth.*
import android.bluetooth.le.BluetoothLeScanner
import android.bluetooth.le.ScanCallback
import android.bluetooth.le.ScanResult
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.graphics.Color
import android.os.Build
import android.os.Bundle
import android.support.annotation.RequiresApi
import android.support.v4.app.Fragment
import android.support.v7.widget.LinearLayoutManager
import android.support.v7.widget.RecyclerView
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import android.widget.TextView
import java.util.*
import kotlin.collections.HashSet
class ScannerFragment : Fragment() {
private lateinit var startButton: Button
private lateinit var stopButton: Button
private lateinit var multilateration: TextView
private lateinit var recyclerView: RecyclerView
private lateinit var linearLayoutManager: LinearLayoutManager
private var btManager: BluetoothManager? = null
private var btAdapter: BluetoothAdapter? = null
private var btScanner: BluetoothLeScanner? = null
var beaconSet: HashSet<Beacon> = HashSet()
var beaconAdapter: BeaconsAdapter? = null
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.fragment_scanner, container, false)
initViews(view)
setUpBluetoothManager()
return view
}
companion object {
private const val REQUEST_ENABLE_BT = 1
private const val PERMISSION_REQUEST_COARSE_LOCATION = 1
}
private fun initViews(view: View) {
startButton = view.findViewById(R.id.startButton)
stopButton = view.findViewById(R.id.stopButton)
recyclerView = view.findViewById(R.id.recyclerView)
startButton.setOnClickListener { onStartScannerButtonClick() }
stopButton.setOnClickListener { onStopScannerButtonClick() }
linearLayoutManager = LinearLayoutManager(context)
recyclerView.layoutManager = linearLayoutManager
beaconAdapter = BeaconsAdapter(beaconSet.toList())
recyclerView.adapter = beaconAdapter
multilateration = view.findViewById(R.id.multilateration)
}
private fun onStartScannerButtonClick() {
startButton.setBackgroundColor(Color.GREEN)
startButton.visibility = View.GONE
stopButton.visibility = View.VISIBLE
beaconSet.clear()
btScanner?.startScan(leScanCallback)
}
private fun onStopScannerButtonClick() {
stopButton.setBackgroundColor(Color.RED)
stopButton.visibility = View.GONE
startButton.visibility = View.VISIBLE
//beaconAdapter?.beaconList?.clear()
beaconSet.clear()
btScanner?.stopScan(leScanCallback)
}
private fun setUpBluetoothManager() {
btManager = activity?.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
btAdapter = btManager!!.adapter
btScanner = btAdapter?.bluetoothLeScanner
if (btAdapter != null && !btAdapter!!.isEnabled) {
val enableIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
startActivityForResult(enableIntent, REQUEST_ENABLE_BT)
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
checkForLocationPermission()
}
}
@RequiresApi(Build.VERSION_CODES.M)
private fun checkForLocationPermission() {
// Make sure we have access coarse location enabled, if not, prompt the user to enable it
if (requireActivity().checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
val builder = AlertDialog.Builder(activity)
builder.setTitle("This app needs location access")
builder.setMessage("Please grant location access so this app can detect the BLE.")
builder.setPositiveButton(android.R.string.ok, null)
builder.setOnDismissListener {
requestPermissions(
arrayOf(Manifest.permission.ACCESS_COARSE_LOCATION),
PERMISSION_REQUEST_COARSE_LOCATION
)
}
builder.show()
}
}
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<String>, grantResults: IntArray
) {
when (requestCode) {
PERMISSION_REQUEST_COARSE_LOCATION -> {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
println("coarse location permission granted")
} else {
val builder = AlertDialog.Builder(activity)
builder.setTitle("Functionality limited")
builder.setMessage("Since location access has not been granted, this app will not be able to discover BLE beacons")
builder.setPositiveButton(android.R.string.ok, null)
builder.setOnDismissListener { }
builder.show()
}
return
}
}
}
private val leScanCallback: ScanCallback = object : ScanCallback() {
@RequiresApi(Build.VERSION_CODES.O)
override fun onScanResult(callbackType: Int, result: ScanResult) {
val scanRecord = result.scanRecord
val beacon = Beacon(result.rssi)
beacon.manufacturer = result.device.name
beacon.macAddress = result.device.address
beacon.rssi = result.rssi
if (scanRecord != null) {
val iBeaconManufactureData = scanRecord.getManufacturerSpecificData(0X004c)
if (iBeaconManufactureData != null && iBeaconManufactureData.size >= 23) {
val iBeaconUUID = Utility.toHexString(iBeaconManufactureData.copyOfRange(2, 18))
val major = Integer.parseInt(
Utility.toHexString(
iBeaconManufactureData.copyOfRange(
18,
20
)
), 16
)
val minor = Integer.parseInt(
Utility.toHexString(
iBeaconManufactureData.copyOfRange(
20,
22
)
), 16
)
beacon.type = Beacon.BeaconType.iBeacon
beacon.name = beacon.manufacturer
beacon.uuid = iBeaconUUID
beacon.major = major
beacon.txPower = result.txPower
beacon.minor = minor
Log.e("BeaconID", "iBeaconUUID:$iBeaconUUID major:$major minor:$minor")
}
if(beacon.name == "Beacon_1" || beacon.name == "Beacon_2" || beacon.name == "Beacon_3" || beacon.name == "Beacon_4" ) {
beaconSet.add(beacon)
}
(recyclerView.adapter as BeaconsAdapter).updateData(beaconSet.toList())
}
}
override fun onScanFailed(errorCode: Int) {
Log.e("Failed", errorCode.toString())
}
}
}
BeaconsAdapter
import android.os.Build
import android.support.annotation.RequiresApi
import android.support.v4.content.ContextCompat
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import java.util.*
class BeaconsAdapter(beacons: List<Beacon>) :
RecyclerView.Adapter<BeaconsAdapter.BeaconHolder>() {
var beaconList: MutableList<Beacon> = beacons.toMutableList()
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BeaconHolder {
val inflater = LayoutInflater.from(parent.context)
return BeaconHolder(inflater, parent)
}
override fun onBindViewHolder(holder: BeaconHolder, pos: Int) {
val beacon: Beacon = beaconList[pos]
holder.bind(beacon)
}
override fun getItemCount() = beaconList.size
@RequiresApi(Build.VERSION_CODES.N)
fun updateData(data: List<Beacon>) {
beaconList.clear()
beaconList.addAll(data)
notifyDataSetChanged()
}
class BeaconHolder(inflater: LayoutInflater, parent: ViewGroup) :
RecyclerView.ViewHolder(inflater.inflate(R.layout.scan_result_items, parent, false)) {
private var image: ImageView? = null
private var mac: TextView? = null
private var name: TextView? = null
private var instanceMajorMinor: TextView? = null
private var namespaceUUID: TextView? = null
private var beaconRSSI: TextView? = null
private val context = parent.context
init {
image = itemView.findViewById(R.id.beacon_image)
mac = itemView.findViewById(R.id.beacon_mac)
name = itemView.findViewById(R.id.beacon_name)
instanceMajorMinor = itemView.findViewById(R.id.beacon_instance_major_minor)
beaconRSSI = itemView.findViewById(R.id.beacon_rssi)
}
fun bind(beacon: Beacon) {
mac?.text = String.format(
context.getString(R.string.mac),
beacon.macAddress
)
beaconRSSI?.text = String.format(
context.getString(R.string.rssi),
beacon.rssi
)
if (beacon.type == Beacon.BeaconType.iBeacon) {
namespaceUUID?.text = String.format(context.getString(R.string.uuid), beacon.uuid)
name?.text = String.format(context.getString(R.string.name), beacon.name)
//namespace
instanceMajorMinor?.text = String.format(
context.getString(R.string.major_minor),
beacon.major,
beacon.minor
)
image?.setImageDrawable(ContextCompat.getDrawable(context, R.drawable.ibeacon))
instanceMajorMinor?.visibility = View.VISIBLE
namespaceUUID?.visibility = View.VISIBLE
}
}
}
}
Beacon
class Beacon(rssi: Int?) {
enum class BeaconType {
iBeacon
}
var macAddress : String? = null
var manufacturer: String? = null
var type: BeaconType = BeaconType.iBeacon
var uuid: String? = null
var name: String? = null
var major: Int? = null
var minor: Int? = null
var txPower: Int? = null
var rssi = rssi
override fun equals(other: Any?): Boolean{
if(this === other) return true
if(other !is Beacon) return false
if(macAddress != other.macAddress) return false
return true
}
override fun hashCode(): Int {
return macAddress?.hashCode() ?:0
}
}
