热水器方波信号，mock水流传感器

square_wave.ino

#define LED_GPIO 26
#define PWM1_Ch 0 
#define PWM1_Res 10 
#define PWM1_Freq 50

void setup() {
  // put your setup code here, to run once:
  ledcAttachPin(LED_GPIO, PWM1_Ch);
  ledcSetup(PWM1_Ch, PWM1_Freq, PWM1_Res);
}

void loop() {
  // put your main code here, to run repeatedly:
  ledcWrite(PWM1_Ch, 50);
}