 uint16_t g_body_len = 0;
 uint16_t g_recv_len = 0;
 
-Child *g_child[CHILD_NUM];
+ChildSwitch *g_child[CHILD_NUM];
 
 char g_need_report = 1;
 unsigned long g_check_ms = 0;
 
 
-class Child {
+class ChildSwitch {
 private:
   int pin_ctrl; /* 控制继电器 */
   int pin_led; /* 控制开关的指示LED */
-  int pin_pwm; /* 输出PWM给触摸面板 */
   int pin_touch; /* 接受来自触摸面板的开关信号  */
 
   int ctrl_value; /* 当前继电器状态 */
 
   int touch_value; /* 当前触摸面板认为的开关状态 */
-  int low_cnt; /* 触摸面板开关信号为0的计数, 当超过阈值, 认为是关信号(因为面板输出不稳定的脉冲) */
+  int low_cnt; /* 触摸面板开关信号为低的计数, 当超过 MAX_LOW_CNT, 认为是关信号(因为面板输出不稳定的脉冲) */
 
 public:
-  Child(int pin_ctrl, int pin_led, int pin_pwm, int pin_touch) {
+  ChildSwitch(int pin_ctrl, int pin_led, int pin_touch) {
     this->pin_ctrl = pin_ctrl;
     this->pin_led = pin_led;
-    this->pin_pwm = pin_pwm;
+//    this->pin_pwm = pin_pwm;
     this->pin_touch = pin_touch;
 
     pinMode(this->pin_ctrl, OUTPUT);

      json data from yunba service
*/
#include <ArduinoJson.h>
#include <PWM.h>

#define MSG_TYPE_UP 0x01
#define MSG_TYPE_DOWN 0x02


    pinMode(this->pin_led, INPUT);

//    SetPinFrequencySafe(this->pin_pwm, 50);
//    pwmWrite(this->pin_pwm, 127);

    pinMode(this->pin_touch, INPUT);

