When outputting RTTTL ringtones, you can still hear a periodic buzzing sound. This problem is fixed in this commit.

src/modules/ExternalNotificationModule.cpp

@@ -126,9 +126,11 @@ int32_t ExternalNotificationModule::runOnce()
                 millis()) {
                 setExternalState(1, !getExternal(1));
             }
-            if (externalTurnedOn[2] + (moduleConfig.external_notification.output_ms ? moduleConfig.external_notification.output_ms
+            // Only toggle buzzer output if not using PWM mode (to avoid conflict with RTTTL)
+            if (!moduleConfig.external_notification.use_pwm &&
+                externalTurnedOn[2] + (moduleConfig.external_notification.output_ms ? moduleConfig.external_notification.output_ms
                                                                                     : EXT_NOTIFICATION_MODULE_OUTPUT_MS) <
-                millis()) {
+                    millis()) {
                 LOG_DEBUG("EXTERNAL 2 %d compared to %d", externalTurnedOn[2] + moduleConfig.external_notification.output_ms,
                           millis());
                 setExternalState(2, !getExternal(2));
@@ -247,7 +249,8 @@ void ExternalNotificationModule::setExternalState(uint8_t index, bool on)
             digitalWrite(moduleConfig.external_notification.output_vibra, on);
         break;
     case 2:
-        if (moduleConfig.external_notification.output_buzzer)
+        // Only control buzzer pin digitally if not using PWM mode
+        if (moduleConfig.external_notification.output_buzzer && !moduleConfig.external_notification.use_pwm)
             digitalWrite(moduleConfig.external_notification.output_buzzer, on);
         break;
     default:
@@ -320,6 +323,11 @@ void ExternalNotificationModule::stopNow()
 #endif
     nagCycleCutoff = 1; // small value
     isNagging = false;
+    // Turn off all outputs
+    for (int i = 0; i < 3; i++) {
+        setExternalState(i, false);
+        externalTurnedOn[i] = 0;
+    }
     setIntervalFromNow(0);
 #ifdef T_WATCH_S3
     drv.stop();
@@ -478,14 +486,17 @@ ProcessMessage ExternalNotificationModule::handleReceived(const meshtastic_MeshP
                 if (containsBell) {
                     LOG_INFO("externalNotificationModule - Notification Bell (Buzzer)");
                     isNagging = true;
-                    if (!moduleConfig.external_notification.use_pwm) {
+                    if (!moduleConfig.external_notification.use_pwm && !moduleConfig.external_notification.use_i2s_as_buzzer) {
                         setExternalState(2, true);
                     } else {
 #ifdef HAS_I2S
-                        audioThread->beginRttl(rtttlConfig.ringtone, strlen_P(rtttlConfig.ringtone));
-#else
-                        rtttl::begin(config.device.buzzer_gpio, rtttlConfig.ringtone);
+                        if (moduleConfig.external_notification.use_i2s_as_buzzer) {
+                            audioThread->beginRttl(rtttlConfig.ringtone, strlen_P(rtttlConfig.ringtone));
+                        } else
 #endif
+                            if (moduleConfig.external_notification.use_pwm) {
+                            rtttl::begin(config.device.buzzer_gpio, rtttlConfig.ringtone);
+                        }
                     }
                     if (moduleConfig.external_notification.nag_timeout) {
                         nagCycleCutoff = millis() + moduleConfig.external_notification.nag_timeout * 1000;
@@ -526,10 +537,11 @@ ProcessMessage ExternalNotificationModule::handleReceived(const meshtastic_MeshP
 #ifdef HAS_I2S
                     if (moduleConfig.external_notification.use_i2s_as_buzzer) {
                         audioThread->beginRttl(rtttlConfig.ringtone, strlen_P(rtttlConfig.ringtone));
-                    }
-#else
-                    rtttl::begin(config.device.buzzer_gpio, rtttlConfig.ringtone);
+                    } else
 #endif
+                        if (moduleConfig.external_notification.use_pwm) {
+                        rtttl::begin(config.device.buzzer_gpio, rtttlConfig.ringtone);
+                    }
                 }
                 if (moduleConfig.external_notification.nag_timeout) {
                     nagCycleCutoff = millis() + moduleConfig.external_notification.nag_timeout * 1000;