diff --git a/app/src/main/java/info/nightscout/androidaps/plugins/pump/danaRS/services/BLEComm.kt b/app/src/main/java/info/nightscout/androidaps/plugins/pump/danaRS/services/BLEComm.kt
index 8e5937238d..e46aff33d7 100644
--- a/app/src/main/java/info/nightscout/androidaps/plugins/pump/danaRS/services/BLEComm.kt
+++ b/app/src/main/java/info/nightscout/androidaps/plugins/pump/danaRS/services/BLEComm.kt
@@ -19,15 +19,13 @@ import info.nightscout.androidaps.plugins.pump.danaRS.activities.EnterPinActivit
 import info.nightscout.androidaps.plugins.pump.danaRS.activities.PairingHelperActivity
 import info.nightscout.androidaps.plugins.pump.danaRS.comm.DanaRSMessageHashTable
 import info.nightscout.androidaps.plugins.pump.danaRS.comm.DanaRS_Packet
-import info.nightscout.androidaps.plugins.pump.danaRS.comm.DanaRS_Packet_Etc_Keep_Connection
-import info.nightscout.androidaps.plugins.pump.danaRS.comm.DanaRS_Packet_General_Get_Pump_Check
 import info.nightscout.androidaps.plugins.pump.danaRS.encryption.BleEncryption
 import info.nightscout.androidaps.plugins.pump.danaRS.events.EventDanaRSPairingSuccess
 import info.nightscout.androidaps.utils.ToastUtils
+import info.nightscout.androidaps.utils.extensions.notify
+import info.nightscout.androidaps.utils.extensions.waitMillis
 import info.nightscout.androidaps.utils.resources.ResourceHelper
 import info.nightscout.androidaps.utils.sharedPreferences.SP
-import okhttp3.internal.notify
-import okhttp3.internal.waitMillis
 import java.util.*
 import java.util.concurrent.ScheduledFuture
 import javax.inject.Inject
@@ -230,7 +228,7 @@ class BLEComm @Inject internal constructor(
             //aapsLogger.debug("writeCharacteristic:" + DanaRS_Packet.toHexString(data))
             bluetoothGatt?.writeCharacteristic(characteristic)
         }).start()
-        waitMillis(50)
+        SystemClock.sleep(50)
     }
 
     private val uartReadBTGattChar: BluetoothGattCharacteristic
diff --git a/app/src/main/java/info/nightscout/androidaps/utils/CryptoUtil.kt b/app/src/main/java/info/nightscout/androidaps/utils/CryptoUtil.kt
index 745f4449ee..ad271e7344 100644
--- a/app/src/main/java/info/nightscout/androidaps/utils/CryptoUtil.kt
+++ b/app/src/main/java/info/nightscout/androidaps/utils/CryptoUtil.kt
@@ -1,5 +1,6 @@
 package info.nightscout.androidaps.utils
 
+import info.nightscout.androidaps.utils.extensions.toHex
 import org.spongycastle.util.encoders.Base64
 import java.nio.ByteBuffer
 import java.security.MessageDigest
@@ -13,38 +14,6 @@ import javax.crypto.spec.GCMParameterSpec
 import javax.crypto.spec.PBEKeySpec
 import javax.crypto.spec.SecretKeySpec
 
-private val HEX_CHARS = "0123456789abcdef"
-private val HEX_CHARS_ARRAY = "0123456789abcdef".toCharArray()
-
-fun String.hexStringToByteArray() : ByteArray {
-
-    val upperCased = this.toLowerCase()
-    val result = ByteArray(length / 2)
-    for (i in 0 until length step 2) {
-        val firstIndex = HEX_CHARS.indexOf(upperCased[i]);
-        val secondIndex = HEX_CHARS.indexOf(upperCased[i + 1]);
-
-        val octet = firstIndex.shl(4).or(secondIndex)
-        result.set(i.shr(1), octet.toByte())
-    }
-
-    return result
-}
-
-fun ByteArray.toHex() : String{
-    val result = StringBuffer()
-
-    forEach {
-        val octet = it.toInt()
-        val firstIndex = (octet and 0xF0).ushr(4)
-        val secondIndex = octet and 0x0F
-        result.append(HEX_CHARS_ARRAY[firstIndex])
-        result.append(HEX_CHARS_ARRAY[secondIndex])
-    }
-
-    return result.toString()
-}
-
 object CryptoUtil {
 
     private const val IV_LENGTH_BYTE = 12
diff --git a/app/src/main/java/info/nightscout/androidaps/utils/extensions/Concurrency.kt b/app/src/main/java/info/nightscout/androidaps/utils/extensions/Concurrency.kt
new file mode 100644
index 0000000000..b958a0ea24
--- /dev/null
+++ b/app/src/main/java/info/nightscout/androidaps/utils/extensions/Concurrency.kt
@@ -0,0 +1,22 @@
+package info.nightscout.androidaps.utils.extensions
+
+
+@Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "NOTHING_TO_INLINE")
+inline fun Any.wait() = (this as Object).wait()
+
+/**
+ * Lock and wait a duration in milliseconds and nanos.
+ * Unlike [java.lang.Object.wait] this interprets 0 as "don't wait" instead of "wait forever".
+ */
+@Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
+fun Any.waitMillis(timeout: Long, nanos: Int = 0) {
+    if (timeout > 0L || nanos > 0) {
+        (this as Object).wait(timeout, nanos)
+    }
+}
+
+@Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "NOTHING_TO_INLINE")
+inline fun Any.notify() = (this as Object).notify()
+
+@Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN", "NOTHING_TO_INLINE")
+inline fun Any.notifyAll() = (this as Object).notifyAll()