平滑三色呼吸单色低亮尾部

project/example/ble/ble_peripheral/app/src/bridge_pwm.c

@@ -390,22 +390,23 @@ __RAM_CODE void Bridge_Service_1ms(void)
 
     /*
      * The low part of the three-color breathing effect cannot use short
-     * continuous W/C pulses reliably. Emit verified 50 us pulses and vary
-     * their density across the fixed 2 kHz frames instead. At the configured
-     * minimum output this gives about 450 emitted pulses per second.
+     * continuous pulses reliably. Emit verified 50 us pulses and vary their
+     * density across the fixed 2 kHz frames instead. Apply this to both the
+     * mixed section and each single-color tail, so no color disappears early
+     * when its hardware-PWM pulse becomes too narrow to light the LEDs.
      */
     if (deviceStatus != POWEROFF &&
         Mode == mode1 && choose_mode_falsg == 5U &&
-        w_mix != 0U && c_mix != 0U) {
+        (w_mix != 0U || c_mix != 0U)) {
         /*
          * Follow the smoothed physical output rather than the next logical
          * target. This lets the old color reach zero before the wait state
          * starts the next color.
          */
-        pdm_w_step =
-            BRIDGE_DUAL_ACTIVE_US * ((uint32_t)w_mix << 12);
-        pdm_c_step =
-            BRIDGE_DUAL_ACTIVE_US * ((uint32_t)c_mix << 12);
+        total_on_us = (w_mix != 0U && c_mix != 0U)
+                    ? BRIDGE_DUAL_ACTIVE_US : BRIDGE_FRAME_US;
+        pdm_w_step = total_on_us * ((uint32_t)w_mix << 12);
+        pdm_c_step = total_on_us * ((uint32_t)c_mix << 12);
 
         if (pdm_w_step < BRIDGE_TRICOLOR_PDM_THRESHOLD &&
             pdm_c_step < BRIDGE_TRICOLOR_PDM_THRESHOLD) {