diff --git a/app/build.gradle b/app/build.gradle
index 47f1f9501..527d63567 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -4,6 +4,7 @@ apply plugin: 'kotlin-parcelize'
 apply plugin: 'kotlinx-serialization'
 apply plugin: 'com.google.gms.google-services'
 apply plugin: 'com.github.triplet.play'
+apply plugin: 'de.mobilej.unmock'
 // apply plugin: "app.brant.amazonappstorepublisher"
 
 // Apply the Crashlytics Gradle plugin
@@ -14,6 +15,11 @@ apply plugin: 'com.google.protobuf'
 
 apply plugin: 'kotlin-kapt'
 
+unMock {
+    keep "android.net.Uri"
+    keep "android.util.Base64"
+}
+
 android {
     /*
     signingConfigs {
diff --git a/app/src/main/java/com/geeksville/mesh/model/Channel.kt b/app/src/main/java/com/geeksville/mesh/model/Channel.kt
index a2af3e92b..665a8de25 100644
--- a/app/src/main/java/com/geeksville/mesh/model/Channel.kt
+++ b/app/src/main/java/com/geeksville/mesh/model/Channel.kt
@@ -1,15 +1,7 @@
 package com.geeksville.mesh.model
 
-import android.graphics.Bitmap
-import android.net.Uri
-import android.util.Base64
 import com.geeksville.mesh.ChannelProtos
-import com.geeksville.mesh.MeshProtos
 import com.google.protobuf.ByteString
-import com.google.zxing.BarcodeFormat
-import com.google.zxing.MultiFormatWriter
-import com.journeyapps.barcodescanner.BarcodeEncoder
-import java.net.MalformedURLException
 
 /** Utility function to make it easy to declare byte arrays - FIXME move someplace better */
 fun byteArrayOfInts(vararg ints: Int) = ByteArray(ints.size) { pos -> ints[pos].toByte() }
@@ -74,14 +66,13 @@ data class Channel(
      */
     val humanName: String
         get() {
-            val suffix: Char = if (settings.psk.size() != 1) {
-                // we have a full PSK, so hash it to generate the suffix
-                val code = settings.psk.fold(0, { acc, x -> acc xor (x.toInt() and 0xff) })
-
-                'A' + (code % 26)
-            } else
-                '0' + settings.psk.byteAt(0).toInt()
+            // start with the PSK then xor in the name
+            val pskCode = xorHash(psk.toByteArray())
+            val nameCode = xorHash(name.toByteArray())
+            val suffix = 'A' + ((pskCode xor nameCode) % 26)
 
             return "#${name}-${suffix}"
         }
 }
+
+fun xorHash(b: ByteArray) = b.fold(0, { acc, x -> acc xor (x.toInt() and 0xff) })
\ No newline at end of file
diff --git a/app/src/test/java/com/geeksville/mesh/NodeInfoTest.kt b/app/src/test/java/com/geeksville/mesh/NodeInfoTest.kt
index aa9059e57..cf6713cc9 100644
--- a/app/src/test/java/com/geeksville/mesh/NodeInfoTest.kt
+++ b/app/src/test/java/com/geeksville/mesh/NodeInfoTest.kt
@@ -8,9 +8,10 @@ import org.junit.Test
 import java.util.*
 
 class NodeInfoTest {
-    val ni1 = NodeInfo(4, MeshUser("+one", "User One", "U1"), Position(37.1, 121.1, 35))
-    val ni2 = NodeInfo(5, MeshUser("+two", "User Two", "U2"), Position(37.11, 121.1, 40))
-    val ni3 = NodeInfo(6, MeshUser("+three", "User Three", "U3"), Position(37.101, 121.1, 40))
+    val model = MeshProtos.HardwareModel.ANDROID_SIM
+    val ni1 = NodeInfo(4, MeshUser("+one", "User One", "U1", model), Position(37.1, 121.1, 35))
+    val ni2 = NodeInfo(5, MeshUser("+two", "User Two", "U2", model), Position(37.11, 121.1, 40))
+    val ni3 = NodeInfo(6, MeshUser("+three", "User Three", "U3", model), Position(37.101, 121.1, 40))
 
     private val currentDefaultLocale = LocaleListCompat.getDefault().get(0)
 
diff --git a/app/src/test/java/com/geeksville/mesh/model/ChannelSetTest.kt b/app/src/test/java/com/geeksville/mesh/model/ChannelSetTest.kt
new file mode 100644
index 000000000..4ac76e13f
--- /dev/null
+++ b/app/src/test/java/com/geeksville/mesh/model/ChannelSetTest.kt
@@ -0,0 +1,16 @@
+package com.geeksville.mesh.model
+
+import android.net.Uri
+import org.junit.Assert
+import org.junit.Test
+
+class ChannelSetTest {
+    /** make sure we match the python and device code behavior */
+    @Test
+    fun matchPython() {
+        val url = Uri.parse("https://www.meshtastic.org/d/#CgUYAyIBAQ")
+        val cs = ChannelSet(url)
+        Assert.assertEquals("LongSlow", cs.primaryChannel!!.name, )
+        Assert.assertEquals("#LongSlow-V", cs.primaryChannel!!.humanName, )
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/java/com/geeksville/mesh/service/MeshServiceTest.kt b/app/src/test/java/com/geeksville/mesh/service/MeshServiceTest.kt
index f8db6328c..aabea7598 100644
--- a/app/src/test/java/com/geeksville/mesh/service/MeshServiceTest.kt
+++ b/app/src/test/java/com/geeksville/mesh/service/MeshServiceTest.kt
@@ -1,31 +1,32 @@
-package com.geeksville.mesh.service
-
-import com.geeksville.mesh.MeshUser
-import com.geeksville.mesh.NodeInfo
-import com.geeksville.mesh.Position
-import org.junit.Assert
-import org.junit.Test
-
-
-class MeshServiceTest {
-
-    val nodeInfo = NodeInfo(4, MeshUser("+one", "User One", "U1"), Position(37.1, 121.1, 35, 10))
-
-    @Test
-    fun givenNodeInfo_whenUpdatingWithNewTime_thenPositionTimeIsUpdated() {
-
-        val newerTime = 20
-        updateNodeInfoTime(nodeInfo, newerTime)
-        Assert.assertEquals(newerTime, nodeInfo.position?.time)
-    }
-
-    @Test
-    fun givenNodeInfo_whenUpdatingWithOldTime_thenPositionTimeIsNotUpdated() {
-        val olderTime = 5
-        val timeBeforeTryingToUpdate = nodeInfo.position?.time
-        updateNodeInfoTime(nodeInfo, olderTime)
-        Assert.assertEquals(timeBeforeTryingToUpdate, nodeInfo.position?.time)
-    }
-}
-
-
+package com.geeksville.mesh.service
+
+import com.geeksville.mesh.MeshProtos
+import com.geeksville.mesh.MeshUser
+import com.geeksville.mesh.NodeInfo
+import com.geeksville.mesh.Position
+import org.junit.Assert
+import org.junit.Test
+
+
+class MeshServiceTest {
+    val model = MeshProtos.HardwareModel.ANDROID_SIM
+    val nodeInfo = NodeInfo(4, MeshUser("+one", "User One", "U1", model), Position(37.1, 121.1, 35, 10))
+
+    @Test
+    fun givenNodeInfo_whenUpdatingWithNewTime_thenPositionTimeIsUpdated() {
+
+        val newerTime = 20
+        updateNodeInfoTime(nodeInfo, newerTime)
+        Assert.assertEquals(newerTime, nodeInfo.position?.time)
+    }
+
+    @Test
+    fun givenNodeInfo_whenUpdatingWithOldTime_thenPositionTimeIsNotUpdated() {
+        val olderTime = 5
+        val timeBeforeTryingToUpdate = nodeInfo.position?.time
+        updateNodeInfoTime(nodeInfo, olderTime)
+        Assert.assertEquals(timeBeforeTryingToUpdate, nodeInfo.position?.time)
+    }
+}
+
+
diff --git a/build.gradle b/build.gradle
index 183d7bf8d..ba99badad 100644
--- a/build.gradle
+++ b/build.gradle
@@ -10,7 +10,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.1.2'
+        classpath 'com.android.tools.build:gradle:4.1.3'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
 
@@ -28,6 +28,9 @@ buildscript {
 
         //classpath "app.brant:amazonappstorepublisher:0.1.0"
         classpath 'com.github.triplet.gradle:play-publisher:2.8.0'
+
+        // for unit testing https://github.com/bjoernQ/unmock-plugin
+        classpath 'com.github.bjoernq:unmockplugin:0.7.6'
     }
 }