fix: recalibrate noise detection to not drop legitimate Somfy frames

The previous threshold (>100 edges in 10 seconds) tripped on the very first
button press — a single Somfy RTS press emits 500-900 edges in under a
second. Worse, the cooldown was measured from the start of the count window,
so the ISR re-enabled on the next loop iteration, missing only the frame
repetitions in flight.

New thresholds: >1000 edges in any 50ms window (~13x peak legitimate rate
for SYMBOL=640µs), with a 2s cooldown measured from the moment the ISR was
disabled. Tooltip and header comment updated to match.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: shailensobhee

data-src/index.html

@@ -949,8 +949,8 @@ <h1 style="text-align: center;"><img src="icon.png" style="width:50px;float:left
                             <label for="cbEnableRadio" style="display:inline-block;cursor:pointer;">Enable Radio</label>
                         </div>
                         <div class="field-group" style="vertical-align:middle;margin-left:7px;float:right;display:inline-block;width:auto;">
-                            <input id="cbNoiseDetection" name="noiseDetection" type="checkbox" data-bind="transceiver.config.noiseDetection" style="display:inline-block;" title="When enabled, the RX interrupt is automatically disabled if more than 100 pulses are detected within 10 seconds (RF noise burst). The interrupt is re-enabled after a 100ms cooldown. Enable this if your radio is frequently disrupted by nearby RF interference." />
-                            <label for="cbNoiseDetection" style="display:inline-block;cursor:pointer;" title="When enabled, the RX interrupt is automatically disabled if more than 100 pulses are detected within 10 seconds (RF noise burst). The interrupt is re-enabled after a 100ms cooldown. Enable this if your radio is frequently disrupted by nearby RF interference.">Noise Detection</label>
+                            <input id="cbNoiseDetection" name="noiseDetection" type="checkbox" data-bind="transceiver.config.noiseDetection" style="display:inline-block;" title="When enabled, the RX interrupt is automatically disabled if more than 1000 pulses are detected within a 50ms window (genuine RF noise burst — well above the peak edge rate of a legitimate Somfy frame). The interrupt is re-enabled after a 2 second cooldown. Enable this only if your radio is frequently overwhelmed by continuous nearby RF interference." />
+                            <label for="cbNoiseDetection" style="display:inline-block;cursor:pointer;" title="When enabled, the RX interrupt is automatically disabled if more than 1000 pulses are detected within a 50ms window (genuine RF noise burst — well above the peak edge rate of a legitimate Somfy frame). The interrupt is re-enabled after a 2 second cooldown. Enable this only if your radio is frequently overwhelmed by continuous nearby RF interference.">Noise Detection</label>
                         </div>
                         <div class="field-group" style="margin-top:-18px;"><label style="font-size:12px;">(default when adding new motors)</label></div>
                         <div class="field-group1" style="white-space:nowrap">

src/Somfy.cpp

@@ -47,9 +47,16 @@ int sort_asc(const void *cmp1, const void *cmp2) {
 }
 
 static int interruptPin = 0;
+// Noise detection thresholds calibrated for Somfy RTS (SYMBOL=640µs → peak
+// legitimate edge rate ~1500/s, i.e. ~75 edges per 50ms burst). Trip at ~13×
+// that to leave ample margin; 2s cooldown prevents immediate re-trip storms.
+static constexpr uint32_t NOISE_WINDOW_MS = 50;
+static constexpr uint32_t NOISE_EDGE_THRESHOLD = 1000;
+static constexpr uint32_t NOISE_COOLDOWN_MS = 2000;
 static volatile bool noiseDetected = false;
-static volatile unsigned long noiseStart = 0;
-static volatile uint32_t noiseCount = 0;
+static volatile unsigned long noiseWindowStart = 0;
+static volatile uint32_t noiseWindowCount = 0;
+static volatile unsigned long noiseDisabledAt = 0;
 static uint8_t bit_length = 56;
 somfy_commands translateSomfyCommand(const String& string) {
     if (string.equalsIgnoreCase("My")) return somfy_commands::My;
@@ -4198,14 +4205,14 @@ void RECEIVE_ATTR Transceiver::handleReceive() {
     if (noiseDetected) return;
     if (somfy.transceiver.config.noiseDetection) {
         unsigned long now = millis();
-        if (noiseStart == 0) noiseStart = now;
-        if (now - noiseStart >= 10000) {
-            noiseStart = now;
-            noiseCount = 0;
+        if (noiseWindowStart == 0 || (now - noiseWindowStart) > NOISE_WINDOW_MS) {
+            noiseWindowStart = now;
+            noiseWindowCount = 0;
         }
-        noiseCount++;
-        if (noiseCount > 100) {
+        noiseWindowCount++;
+        if (noiseWindowCount > NOISE_EDGE_THRESHOLD) {
             gpio_intr_disable((gpio_num_t)interruptPin);
+            noiseDisabledAt = now;
             noiseDetected = true;
             return;
         }
@@ -4885,11 +4892,11 @@ bool Transceiver::begin() {
 void Transceiver::loop() {
   somfy_rx_t rx;
   if (noiseDetected && rxmode != 3 && this->config.noiseDetection) {
-    if (millis() - noiseStart > 100) {
+    if (millis() - noiseDisabledAt > NOISE_COOLDOWN_MS) {
       gpio_intr_enable((gpio_num_t)interruptPin);
       noiseDetected = false;
-      noiseStart = 0;
-      noiseCount = 0;
+      noiseWindowStart = 0;
+      noiseWindowCount = 0;
     }
   }
   if(rxmode == 3) {

src/Somfy.h

@@ -426,7 +426,7 @@ struct transceiver_config_t {
     float deviation = 47.60;          // Set the Frequency deviation in kHz. Value from 1.58 to 380.85. Default is 47.60 kHz.
     float rxBandwidth = 99.97;        // Receive bandwidth in kHz.  Value from 58.03 to 812.50.  Default is 99.97kHz.
     int8_t txPower = 10;              // Transmission power {-30, -20, -15, -10, -6, 0, 5, 7, 10, 11, 12}.  Default is 12.
-    bool noiseDetection = false;      // Disable RX interrupt when RF noise is detected (>100 pulses/10s)
+    bool noiseDetection = false;      // Disable RX interrupt on RF noise burst (>1000 pulses/50ms, 2s cooldown)
 /*    
     bool internalCCMode = false;      // Use internal transmission mode FIFO buffers.
     byte modulationMode = 2;          // Modulation mode. 0 = 2-FSK, 1 = GFSK, 2 = ASK/OOK, 3 = 4-FSK, 4 = MSK.