Question

I am writing a code for Arduino. What it should do is:

It has to Monitor 6 analog inputs and if there is any activity on any of them, send (number of active pin + value on its pin) via serial connection.

On the other side of the serial connection, Other program will make decision on this given information.

How best to do it?

Answer 1

One solution might be like this:

int analogPin1 = 1; 
    int analogPin2 = 2; 
    int analogPin3 = 3; 
    int analogPin4 = 4; 
    int analogPin5 = 5; 
    int analogPin6 = 6; 

    int val = 0;
    byte sendAnalog=0;         

    void setup()
    {
      Serial.begin(9600);  
    }

    void loop()
    {
    val=analogRead(analogPin1);
    if(val>0){
        Serial.print("1");
        sendAnalog=val*0.24926697;
        Serial.print(sendAnalog,BYTE);

    }
    val=analogRead(analogPin2);
        if(val>0){
        Serial.print("2");
        sendAnalog=val*0.24926697;
        Serial.print(sendAnalog,BYTE);

    }
val=analogRead(analogPin3);
    if(val>0){
        Serial.print("3");
        sendAnalog=val*0.24926697;
        Serial.print(sendAnalog,BYTE);

    }
val=analogRead(analogPin4);
    if(val>0){
        Serial.print("4");
        sendAnalog=val*0.24926697;
        Serial.print(sendAnalog,BYTE);

    }

}

AD converter is storing 10 bits values. Maximum value by AD converter is 1023 ([2^10-1]). Module for serial communication is sending bytes of data, so you need scale 1023 to 255. Equation is (255/1023)*currentAnalogValue (so it is 0.249266*currentAnalogValue). In your computer application, you need inverse equation 1023/255*receivedByte to receive original value.