diff --git a/sdk b/sdk
index 57cf05c..baafde6 160000
--- a/sdk
+++ b/sdk
@@ -1 +1 @@
-Subproject commit 57cf05c056145c69697f94f5320581ad1dcb8cc3
+Subproject commit baafde681f0e2f87659d06e8801f9ec9ea1c2277
diff --git a/usrc/main.cpp b/usrc/main.cpp
index d44a525..bfc8a41 100644
--- a/usrc/main.cpp
+++ b/usrc/main.cpp
@@ -53,19 +53,47 @@ static int32_t getDeviceId() {
  *******************************************************************************/
 class PWMCtrler : public ZIPWMCtrl {
   ZPWMGenerator pwm;
-  int32_t       freq;
-  int32_t       duty;
-  int32_t       state;
+  int32_t       m_freq = 50000;
+  int32_t       m_duty = 50;
+  int32_t       m_state;
 
  public:
-  void            initialize() { pwm.initialize(&htim2, TIM_CHANNEL_2, 25000, 1); }
+  void initialize() { pwm.initialize(&htim2, TIM_CHANNEL_2, 25000, 1); }
+
+  virtual int32_t pwm_set_state(int32_t state) {
+    if (state) {
+      pwm.startPWM(m_freq, m_duty);
+    } else {
+      pwm.stopPWM();
+    }
+    m_state = state;
+  }
+  virtual int32_t pwm_get_state(int32_t& state) {
+    state = m_state;
+    return 0;
+  }
+
   virtual int32_t set_pwm_duty(int32_t duty) {
-    pwm.startPWM(duty);
+    m_duty = duty;
+    if (m_state) {
+      pwm.startPWM(m_freq, m_duty);
+    }
+  }
+  virtual int32_t get_pwm_duty(int32_t& duty) {
+    duty = m_duty;
+    return 0;
+  }
+
+  virtual int32_t set_pwm_freq(int32_t freq) {
+    m_freq = freq;
+    if (m_state) {
+      pwm.startPWM(m_freq, m_duty);
+    }
+  }
+  virtual int32_t get_pwm_freq(int32_t& duty) {
+    duty = m_freq;
     return 0;
   }
-  virtual int32_t set_pwm_freq(int32_t freq) {}
-  virtual int32_t get_pwm_duty() {}
-  virtual int32_t get_pwm_freq() {}
 };
 
 PWMCtrler pwmCtrler;
@@ -126,7 +154,10 @@ void umain() {
                   {.pin = PC7, .mode = ZGPIO::kMode_pulldown, .mirror = false, .initLevel = false, .log_when_setstate = false},
                   {.pin = PC8, .mode = ZGPIO::kMode_pulldown, .mirror = false, .initLevel = false, .log_when_setstate = false},
               },
-          .pwmctrl = &pwmCtrler,
+          .pwmctrl =
+              {
+                  &pwmCtrler,
+              },
       };
   initer.init(&cfg);
   initsubmodule();