From a212d562cb0420ac78136c480e5feeb1803609f1 Mon Sep 17 00:00:00 2001
From: cjkas <slaw.cz@gmail.com>
Date: Mon, 12 Oct 2026 18:32:12 +0200
Subject: [PATCH] fix: send frequency scan events from loop() only

beginFrequencyScan, endFrequencyScan and apply() run on async_tcp from the
web handlers and emitted into the socket event buffer loop() also writes,
so an event could be mixed up or dropped.  They now only flag the change
and Transceiver::loop() sends it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/Somfy.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/Somfy.cpp b/src/Somfy.cpp
index b5ba1b3..a22c5af 100644
--- a/src/Somfy.cpp
+++ b/src/Somfy.cpp
@@ -4055,6 +4055,10 @@ float markFreq = 433.0f;
 int markRSSI = -100;
 uint32_t lastScan = 0;
 static uint32_t scanStart = 0;
+// Scan state changes made off loop() (the web handlers and apply() run on
+// async_tcp) are only flagged here.  The socket event buffer is shared, so
+// loop() sends the event.
+static std::atomic<bool> scanEmitPending{false};
 // A scan nobody ended (closed browser tab) stops on its own after this long so
 // the radio doesn't stay unable to transmit.
 #define SCAN_MAX_MS 300000
@@ -4076,7 +4080,7 @@ void Transceiver::beginFrequencyScan() {
     ELECHOUSE_cc1101.setMHZ(currFreq);
     ESP_LOGD(TAG, "Begin frequency scan on Pin #%d", this->config.RXPin);
     attachInterrupt(interruptPin, handleReceive, CHANGE);
-    this->emitFrequencyScan();
+    scanEmitPending = true;
   }
 }
 void Transceiver::processFrequencyScan(bool received) {
@@ -4114,7 +4118,7 @@ void Transceiver::endFrequencyScan() {
     if(interruptPin > 0) detachInterrupt(interruptPin); 
     interruptPin = 0;
     this->config.apply();
-    this->emitFrequencyScan();
+    scanEmitPending = true;
   }
   // Even if something else already ended the scan, nothing may keep TX suspended.
   this->resumeTx(TX_SUSPEND_SCAN);
@@ -4528,7 +4532,7 @@ void transceiver_config_t::apply() {
     somfy.transceiver.disableReceive();
     if(wasScanning) {
       somfy.transceiver.resumeTx(TX_SUSPEND_SCAN);
-      somfy.transceiver.emitFrequencyScan();
+      scanEmitPending = true;
     }
     bit_length = this->type;    
     if(this->enabled) {
@@ -4648,6 +4652,7 @@ void Transceiver::loop() {
     // Line the simulated shades up with what actually went on air.
     somfy.processTxEvent(evt);
   }
+  if(scanEmitPending.exchange(false)) this->emitFrequencyScan();
   if (noiseDetected && rxmode != 3 && this->config.noiseDetection) {
     if (millis() - noiseStart > 100) {
       gpio_intr_enable((gpio_num_t)interruptPin);