A. method: continuous access to n sample values for arithmetic operations. When the value of n is large: the signal smoothness is high, but with lower sensitivity; when the value of n is small: the signal smoothness is lower, but the sensitivity is higher. Select N value: general flow, N=12, pressure: N=4

B. advantages: apply to filter the signal with random interference, this signal is characterized by an average, the signal in the vicinity of a range of values fluctuate.

C. disadvantages: it is not suitable for the measuring speed slower or requiring faster real-time control, and it is a little wasting RAM.

int Filter_Value; 
  
void setup () {
   Serial.begin (9600); / / initialize the serial communication 
   randomSeed (analogRead (0)); / / random seed 
} 
  
void loop () {
   Filter_Value = Filter (); / / get the filter output value 
   Serial.println (Filter_Value); / / serial output 
   delay (50); 
} 
  
/ / Used to randomly generate a current value of around 300 
int Get_AD () {
   return random (295, 305); 
} 
  
/ / Arithmetic average filter 
# define FILTER_N 12 
int Filter () {
   int i; 
   int filter_sum = 0; 
   for (i = 0; i <FILTER_N; i + +) {
     filter_sum + = Get_AD (); 
     delay (1); 
   } 
   return (int) (filter_sum / FILTER_N); 
}