Updated the processAudioLoop to mke sure that the buffer was always flushed after an output stream so we didn't miss any characters. Also made many modifications to the python script running on the Pico to ensure that we get dual inputs and neater outputs now.

Also updated the testModelActivity to a more robust USB connection permissions testing and connection testing....

.idea/misc.xml

@@ -1,4 +1,3 @@
-<?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
   <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">

app/.gitignore

@@ -44,7 +44,7 @@ captures/
 
 # Keystore files (NEVER commit these!)
 *.jks
-*.keystore
+# *.keystore
 *.pem
 
 # OS-specific files

app/build.gradle.kts

@@ -7,12 +7,22 @@ android {
     namespace = "net.mmanningau.speechtokeyboard"
     compileSdk = 36
 
+    signingConfigs {
+        getByName("debug") {
+            // This tells Gradle to look for the key in the same folder as this build file
+            storeFile = file("debug.keystore")
+            storePassword = "android"
+            keyAlias = "androiddebugkey"
+            keyPassword = "android"
+        }
+    }
+
     defaultConfig {
         applicationId = "net.mmanningau.speechtokeyboard"
         minSdk = 28
         targetSdk = 36
-        versionCode = 12
+        versionCode = 15
-        versionName = "1.1"
+        versionName = "1.1.3"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
@@ -29,6 +39,8 @@ android {
             applicationIdSuffix = ".streaming"
             // This changes the app name on your homescreen to "MyApp (Dev)"
             resValue("string", "app_name", "Speech To Keyboard (Streaming)")
+            // Explicitly tell the debug build to use the config we defined above
+            signingConfig = signingConfigs["debug"]
         }
     }
     compileOptions {

app/src/main/java/net/mmanningau/speechtokeyboard/TestModelActivity.kt

@@ -17,7 +17,6 @@ import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
 import com.hoho.android.usbserial.driver.UsbSerialPort
 import com.hoho.android.usbserial.driver.UsbSerialProber
-import com.hoho.android.usbserial.util.SerialInputOutputManager
 import com.k2fsa.sherpa.onnx.EndpointConfig
 import com.k2fsa.sherpa.onnx.EndpointRule
 import com.k2fsa.sherpa.onnx.FeatureConfig
@@ -26,7 +25,6 @@ import com.k2fsa.sherpa.onnx.OnlineRecognizerConfig
 import com.k2fsa.sherpa.onnx.OnlineTransducerModelConfig
 import com.k2fsa.sherpa.onnx.OnlineStream
 import java.io.File
-
 import com.k2fsa.sherpa.onnx.OfflinePunctuation
 import com.k2fsa.sherpa.onnx.OfflinePunctuationConfig
 import com.k2fsa.sherpa.onnx.OfflinePunctuationModelConfig
@@ -48,6 +46,7 @@ class TestModelActivity : AppCompatActivity() {
 
     // USB Components
     private var usbPort: UsbSerialPort? = null
+    private val ACTION_USB_PERMISSION = "net.mmanningau.speechtokeyboard.USB_PERMISSION"
 
     // Text History
     private var committedText = ""
@@ -61,7 +60,9 @@ class TestModelActivity : AppCompatActivity() {
         micButton = findViewById(R.id.btn_mic_toggle)
 
         checkAudioPermission()
-        connectToPico() // Try to auto-connect USB on start
+
+        // Try to connect immediately on startup
+        attemptUsbConnection()
 
         // Initialize Engine
         initSherpaModel()
@@ -73,7 +74,7 @@ class TestModelActivity : AppCompatActivity() {
     }
 
     // ----------------------------------------------------------------
-    // 1. ENGINE INITIALIZATION (The "Missing Code")
+    // 1. ENGINE INITIALIZATION
     // ----------------------------------------------------------------
     private fun initSherpaModel() {
         val modelDir = File(filesDir, "sherpa-model")
@@ -84,14 +85,12 @@ class TestModelActivity : AppCompatActivity() {
         }
 
         try {
-            // 1. Define Model Paths
             val transducerConfig = OnlineTransducerModelConfig(
                 encoder = File(modelDir, "encoder.onnx").absolutePath,
                 decoder = File(modelDir, "decoder.onnx").absolutePath,
                 joiner = File(modelDir, "joiner.onnx").absolutePath
             )
 
-            // 2. Define General Config
             val onlineModelConfig = com.k2fsa.sherpa.onnx.OnlineModelConfig(
                 transducer = transducerConfig,
                 tokens = File(modelDir, "tokens.txt").absolutePath,
@@ -100,41 +99,33 @@ class TestModelActivity : AppCompatActivity() {
                 modelType = "zipformer"
             )
 
-            // 3. Define Endpoint Rule (The fix for your error)
-            // rule1 = detected silence after speech. We set this to 2.4 seconds.
             val silenceRule = EndpointRule(
                 mustContainNonSilence = false,
-                minTrailingSilence = 2.4f,
+                minTrailingSilence = 1.2f,
                 minUtteranceLength = 0.0f
             )
 
-            // 4. Create Recognizer Config
             val config = OnlineRecognizerConfig(
                 featConfig = FeatureConfig(sampleRate = 16000, featureDim = 80),
                 modelConfig = onlineModelConfig,
-                endpointConfig = EndpointConfig(rule1 = silenceRule), // Pass the rule object here
+                endpointConfig = EndpointConfig(rule1 = silenceRule),
                 enableEndpoint = true,
                 decodingMethod = "greedy_search",
                 maxActivePaths = 4
             )
 
-            // recognizer = OnlineRecognizer(assetManager = assets, config = config)
             recognizer = OnlineRecognizer(config = config)
             stream = recognizer?.createStream()
 
-            outputText.text = "Engine Loaded. Ready to Stream."
+            outputText.text = "Engine Loaded. Ready."
 
-            // ... existing recognizer init code ...
+            // Initialize Punctuation Engine
-
-// 5. Initialize Punctuation Engine
             val punctPath = File(modelDir, "punct_model.onnx").absolutePath
 
             if (File(punctPath).exists()) {
-                // CORRECTED: Wrap the path inside 'OfflinePunctuationModelConfig'
                 val punctConfig = OfflinePunctuationConfig(
                     model = OfflinePunctuationModelConfig(ctTransformer = punctPath)
                 )
-
                 punctuator = OfflinePunctuation(config = punctConfig)
                 outputText.append("\n+ Punctuation Ready")
             } else {
@@ -148,7 +139,7 @@ class TestModelActivity : AppCompatActivity() {
     }
 
     // ----------------------------------------------------------------
-    // 2. AUDIO LOOP (The "Manual" Listener)
+    // 2. AUDIO LOOP
     // ----------------------------------------------------------------
     private fun toggleRecording() {
         if (isRecording) {
@@ -164,9 +155,11 @@ class TestModelActivity : AppCompatActivity() {
             return
         }
 
-        // FIX 1: CLEAR THE BUFFER
+        // Before we start, check USB connection again!
-        // This prevents the "ghost text" from the previous session appearing
+        if (usbPort == null) {
-        // when you hit record again.
+            attemptUsbConnection()
+        }
+
         stream?.let { activeStream ->
             recognizer?.reset(activeStream)
         }
@@ -185,9 +178,6 @@ class TestModelActivity : AppCompatActivity() {
         isRecording = false
         recordingThread?.join()
         micButton.clearColorFilter()
-
-        // Just show what we have, don't overwrite with "[Stopped]"
-        // to prevent visual jarring.
         outputText.append("\n[Stopped]")
     }
 
@@ -195,7 +185,6 @@ class TestModelActivity : AppCompatActivity() {
         val sampleRate = 16000
         val bufferSize = AudioRecord.getMinBufferSize(sampleRate, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT)
 
-        // Guard clauses
         val localRec = recognizer ?: return
         val localStream = stream ?: return
 
@@ -212,7 +201,6 @@ class TestModelActivity : AppCompatActivity() {
             val ret = record.read(buffer, 0, buffer.size)
             if (ret > 0) {
                 val samples = FloatArray(ret) { buffer[it] / 32768.0f }
-
                 localStream.acceptWaveform(samples, sampleRate)
 
                 while (localRec.isReady(localStream)) {
@@ -226,28 +214,18 @@ class TestModelActivity : AppCompatActivity() {
                     val cleanText = text.lowercase()
 
                     if (isEndpoint) {
-                        // FIX 2: THE ORDER OF OPERATIONS
+                        // CASE A: Natural Pause (Sentence Finished)
-
-                        // A. Update UI first
-                        // 1. PUNCTUATE
-                        // We pass the raw text to the punctuator
                         val punctuatedText = punctuator?.addPunctuation(cleanText) ?: cleanText
 
                         runOnUiThread {
-                            // 2. Commit the BEAUTIFUL text
                             committedText += "$punctuatedText "
                             outputText.text = committedText
                             sendToPico("$punctuatedText ")
                         }
-
-                        // B. RESET IMMEDIATELY ON BACKGROUND THREAD
-                        // We do this HERE, not inside runOnUiThread.
-                        // This guarantees the stream is clean BEFORE the loop
-                        // reads the next chunk of audio.
                         localRec.reset(localStream)
-
                     } else {
-                        // Standard partial update
+                        // CASE B: Partial (Still talking)
+                        // Update screen ONLY, do not send to Pico yet
                         runOnUiThread {
                             outputText.text = "$committedText $cleanText"
                         }
@@ -255,37 +233,106 @@ class TestModelActivity : AppCompatActivity() {
                 }
             }
         }
+
+        // --- NEW: THE FLUSH BLOCK ---
+        // This runs when you hit "Stop". It grabs the last unspoken words.
+        val finalTail = localRec.getResult(localStream).text
+        if (finalTail.isNotEmpty()) {
+            val cleanTail = finalTail.lowercase()
+            val punctuatedTail = punctuator?.addPunctuation(cleanTail) ?: cleanTail
+
+            runOnUiThread {
+                committedText += "$punctuatedTail "
+                outputText.text = committedText
+                // FORCE SEND the remaining text
+                sendToPico("$punctuatedTail ")
+            }
+            // Reset for next time
+            localRec.reset(localStream)
+        }
+        // -----------------------------
+
         record.stop()
         record.release()
     }
 
     // ----------------------------------------------------------------
-    // 3. USB LOGIC (Unchanged from before)
+    // 3. ROBUST USB LOGIC (FIXED)
     // ----------------------------------------------------------------
-    private fun connectToPico() {
-        val usbManager = getSystemService(Context.USB_SERVICE) as UsbManager
-        val availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(usbManager)
-        if (availableDrivers.isEmpty()) return
 
+    // RENAMED from 'connectToPico' to be clearer
+    private fun attemptUsbConnection() {
+        val usbManager = getSystemService(Context.USB_SERVICE) as UsbManager
+
+        // 1. Find Driver
+        val availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(usbManager)
+        if (availableDrivers.isEmpty()) {
+            Log.d("USB", "No drivers found")
+            return
+        }
         val driver = availableDrivers[0]
-        val connection = usbManager.openDevice(driver.device) ?: return
+
+        // 2. Check Permission
+        if (!usbManager.hasPermission(driver.device)) {
+            Log.d("USB", "Requesting Permission...")
+            val pendingIntent = android.app.PendingIntent.getBroadcast(
+                this,
+                0,
+                android.content.Intent(ACTION_USB_PERMISSION),
+                android.app.PendingIntent.FLAG_IMMUTABLE
+            )
+            usbManager.requestPermission(driver.device, pendingIntent)
+            return
+        }
+
+        // 3. Open Connection
+        try {
+            val connection = usbManager.openDevice(driver.device)
+            if (connection == null) {
+                Log.e("USB", "openDevice returned null")
+                return
+            }
+
+            // Clean up old port if exists
+            try { usbPort?.close() } catch (e: Exception) {}
 
             usbPort = driver.ports[0]
-        try {
             usbPort?.open(connection)
             usbPort?.setParameters(115200, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE)
-            outputText.append("\n> USB Connected")
+
+            Log.d("USB", "Success! Connected at 115200")
+
+            // UI Feedback
+            runOnUiThread {
+                Toast.makeText(this, "USB Connected", Toast.LENGTH_SHORT).show()
+            }
+
         } catch (e: Exception) {
-            outputText.append("\n> USB Error: ${e.message}")
+            Log.e("USB", "Connection Error", e)
+            usbPort = null
         }
     }
 
     private fun sendToPico(text: String) {
-        if (usbPort == null) return
+        // AUTO-RECONNECT FEATURE
+        if (usbPort == null) {
+            Log.d("USB", "Port null, trying to reconnect...")
+            attemptUsbConnection()
+
+            if (usbPort == null) {
+                Log.e("USB", "Reconnect failed.")
+                return
+            }
+        }
+
         try {
-            usbPort?.write(text.toByteArray(Charsets.UTF_8), 500)
+            val data = text.toByteArray(Charsets.UTF_8)
+            usbPort?.write(data, 500)
+            Log.d("USB", "Sent: $text")
         } catch (e: Exception) {
-            // Log error
+            Log.e("USB", "Write Failed", e)
+            // Force reset on next try
+            usbPort = null
         }
     }