From 80167fd9e558da52861d9c29dd85948006b3da05 Mon Sep 17 00:00:00 2001
From: HVBT Dev <dev@hvbt>
Date: Tue, 28 Jul 2026 01:29:12 +0530
Subject: [PATCH] Restore S300 frame parsing for prefix frames

---
 lib/core/protocol/s300_parser.dart      | 8 +++-----
 lib/core/providers/sensor_provider.dart | 3 ---
 test/s300_parser_test.dart              | 2 +-
 3 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/lib/core/protocol/s300_parser.dart b/lib/core/protocol/s300_parser.dart
index 99039c6..78187ad 100644
--- a/lib/core/protocol/s300_parser.dart
+++ b/lib/core/protocol/s300_parser.dart
@@ -6,11 +6,9 @@ import 'neg8.dart';
 bool isS300PlaceholderFrame(Uint8List frame) {
   if (frame.length != 128) return false;
 
-  // The S300 Bluetooth stream can interleave a valid-checksum placeholder
-  // frame that is not the SManager live sensor frame. It has a fixed header
-  // and zero/overflow values for speed, TPS, injection and ignition, then it
-  // overwrites the dashboard with stale/empty values. Keep this check near the
-  // parser so Bluetooth diagnostics can still receive and count raw frames.
+  // Diagnostic signature observed in the S300 Bluetooth stream. Do not use
+  // this to drop frames globally; current captures show real changing data can
+  // still be carried in frames with this prefix.
   return frame[0] == 0x1B &&
       frame[1] == 0x00 &&
       frame[2] == 0x14 &&
diff --git a/lib/core/providers/sensor_provider.dart b/lib/core/providers/sensor_provider.dart
index e7bc171..8453a39 100644
--- a/lib/core/providers/sensor_provider.dart
+++ b/lib/core/providers/sensor_provider.dart
@@ -15,9 +15,6 @@ final sensorStateProvider = StreamProvider<SensorState>((ref) async* {
 
   await for (final frame in btNotifier.frameStream) {
     if (ecuType == EcuType.s300) {
-      if (isS300PlaceholderFrame(frame)) {
-        continue;
-      }
       yield parseS300(frame, validateChecksum: false);
     } else {
       yield parseKPro(frame);
diff --git a/test/s300_parser_test.dart b/test/s300_parser_test.dart
index 50367d4..33af8c2 100644
--- a/test/s300_parser_test.dart
+++ b/test/s300_parser_test.dart
@@ -161,7 +161,7 @@ void main() {
       expect(state.rpm, equals(1000.0));
     });
 
-    test('detects known S300 placeholder frame', () {
+    test('detects known S300 prefix signature', () {
       final frame = Uint8List(128);
       final signature = [
         0x1B,