diff --git a/server/config.example.yaml b/server/config.example.yaml
index 1c889b6d..b1d10e02 100644
--- a/server/config.example.yaml
+++ b/server/config.example.yaml
@@ -42,6 +42,8 @@ homeAssistant:
     brainslugHost: "neato-vacuum.local"
     brainslugPort: 6053
     brainslugKey: "REPLACE_WITH_ESPHOME_NOISE_PSK"
+    # Optional: mirror raw ESPHome lidar log output to a local file for debugging.
+    brainslugLogFile: "/tmp/brainslug-lidar.log"
   lift:
     # Two Home Assistant switches controlling lift direction.
     # Raise sequence: down off -> wait interlockMs -> up on
diff --git a/server/src/services/neatoService/index.js b/server/src/services/neatoService/index.js
index 840bd0f4..4aa92358 100644
--- a/server/src/services/neatoService/index.js
+++ b/server/src/services/neatoService/index.js
@@ -31,6 +31,7 @@ const RESUME_DELAY_MS = 3000;
 const brainslugHost = String(neatoConfig.brainslugHost || '').trim();
 const brainslugPort = Number(neatoConfig.brainslugPort) || 6053;
 const brainslugKey = String(neatoConfig.brainslugKey || '').trim();
+const brainslugLogFile = String(neatoConfig.brainslugLogFile || '').trim();
 let lidarRuntime = null;
 
 function entityId(domain, suffix) {
@@ -281,6 +282,7 @@ lidarRuntime =
         host: brainslugHost,
         port: brainslugPort,
         key: brainslugKey,
+        logFile: brainslugLogFile,
         shouldPoll: () => Boolean(homeAssistantEnabled && isHomeAssistantConnected() && hasVerifiedSockets()),
         requestScan: requestLidarScan,
       })
diff --git a/server/src/services/neatoService/lidarRuntime.js b/server/src/services/neatoService/lidarRuntime.js
index 5667dc4e..3d54c182 100644
--- a/server/src/services/neatoService/lidarRuntime.js
+++ b/server/src/services/neatoService/lidarRuntime.js
@@ -1,5 +1,6 @@
 const { spawn } = require('child_process');
 const EventEmitter = require('events');
+const fs = require('fs');
 
 const SCAN_TIMEOUT_MS = 4000;
 const RECONNECT_DELAY_MS = 5000;
@@ -41,7 +42,7 @@ function parseRotationSpeed(payload) {
   return Number(match[1]);
 }
 
-function createLidarRuntime({ logger, host, port = 6053, key, shouldPoll, requestScan }) {
+function createLidarRuntime({ logger, host, port = 6053, key, logFile = '', shouldPoll, requestScan }) {
   const events = new EventEmitter();
   const state = {
     connected: false,
@@ -53,6 +54,7 @@ function createLidarRuntime({ logger, host, port = 6053, key, shouldPoll, reques
     currentScan: null,
     requestInFlight: false,
     requestStartedAt: 0,
+    logStream: null,
   };
 
   function emitStatus() {
@@ -137,6 +139,9 @@ function createLidarRuntime({ logger, host, port = 6053, key, shouldPoll, reques
   }
 
   function handleStdoutChunk(chunk) {
+    if (state.logStream) {
+      state.logStream.write(String(chunk || ''));
+    }
     state.stdoutBuffer += String(chunk || '');
     const lines = state.stdoutBuffer.split(/\r?\n/);
     state.stdoutBuffer = lines.pop() || '';
@@ -163,9 +168,31 @@ function createLidarRuntime({ logger, host, port = 6053, key, shouldPoll, reques
     }
   }
 
+  function ensureLogStream() {
+    if (!logFile || state.logStream) return;
+    try {
+      state.logStream = fs.createWriteStream(logFile, { flags: 'a' });
+      logger.info('Neato lidar raw log capture enabled', { logFile });
+    } catch (err) {
+      logger.warn('Failed to open Neato lidar raw log file', { logFile, error: err.message });
+      state.logStream = null;
+    }
+  }
+
+  function closeLogStream() {
+    if (!state.logStream) return;
+    try {
+      state.logStream.end();
+    } catch (err) {
+      logger.warn('Failed to close Neato lidar raw log file', err.message);
+    }
+    state.logStream = null;
+  }
+
   function startLogStream() {
     if (!host || !key) return;
     if (state.process) return;
+    ensureLogStream();
 
     const args = [
       '--from',
@@ -244,6 +271,7 @@ function createLidarRuntime({ logger, host, port = 6053, key, shouldPoll, reques
     clearPollSoonTimer();
     clearRequestTimeoutTimer();
     teardownProcess();
+    closeLogStream();
   }
 
   function getState() {