3-A02YYUW.ino

/*
  *@File  : DFRobot_Distance_A02.ino 
  *@Brief : This example use A02YYUW ultrasonic sensor to measure distance
  *         With initialization completed, We can get distance value 
  *@Copyright [DFRobot](https://www.dfrobot.com),2016         
  *           GUN Lesser General Pulic License
  *@version V1.0           
  *@data  2019-8-28
*/

#include <SoftwareSerial.h>

SoftwareSerial mySerial(11,10); // RX, TX
unsigned char data[4]={};
float distance;

SoftwareSerial mySerial1(8,7); // RX, TX
unsigned char data1[4]={};
float distance1;

SoftwareSerial mySerial2(5,4); // RX, TX
unsigned char data2[4]={};
float distance2;

void setup()
{
 Serial.begin(57600);
 mySerial.begin(9600); 
 mySerial1.begin(9600); 
 mySerial2.begin(9600); 
}

void loop()
{
    mySerial.listen();
    delay(100);

    if (mySerial.isListening()) {

        while ((mySerial.available() > 0)) {
            do{
            for(int i=0;i<4;i++)
            {
            data[i]=mySerial.read();
            }
            }while(mySerial.read()==0xff);

            mySerial.flush();

            if(data[0]==0xff){
                int sum;
                sum=(data[0]+data[1]+data[2])&0x00FF;
                if(sum==data[3])
                {
                distance=(data[1]<<8)+data[2];
                if(distance>30)
                    {
                    int distance = distance/10;
                }else 
                        {
                        distance = -1;
                        }
                }else distance = -2;
            }
        }

    }else{
    distance = -3;
    }

    mySerial1.listen();
    delay(100);

    if (mySerial1.isListening()) {

        while ((mySerial1.available() > 0)) {
            do{
            for(int i=0;i<4;i++)
            {
            data1[i]=mySerial1.read();
            }
            }while(mySerial1.read()==0xff);

            mySerial1.flush();

            if(data1[0]==0xff){
                int sum1;
                sum1=(data1[0]+data1[1]+data1[2])&0x00FF;
                if(sum1==data1[3])
                {
                distance1=(data1[1]<<8)+data1[2];
                if(distance1>30)
                    {
                    int distance1 = distance1/10;
                    }else 
                        {
                        distance1 = -1;
                        }
                }else distance1 = -2;
            }
        }

    }else{
    distance1 = -3;
    }

    mySerial2.listen();
    delay(100);

    if (mySerial2.isListening()) {

        while ((mySerial2.available() > 0)) {
            do{
            for(int i=0;i<4;i++)
            {
            data2[i]=mySerial2.read();
            }
            }while(mySerial2.read()==0xff);

            mySerial2.flush();

            if(data2[0]==0xff){
                int sum2;
                sum2=(data2[0]+data2[1]+data2[2])&0x00FF;
                if(sum2==data2[3])
                {
                distance2=(data2[1]<<8)+data2[2];
                if(distance2>30)
                    {
                    int distance2 = distance2/10;
                    }else 
                        {
                        distance2 = -1;
                        }
                }else distance2 = -2;
            }
        }

    }else{
    distance2 = -3;
    }

    Serial.println((String) distance + " " + distance1 + " " + distance2);

    memset(data, 0, sizeof(data));
    memset(data1, 0, sizeof(data1));
    memset(data2, 0, sizeof(data2));

    int sum=0;
    int sum1=0;
    int sum2=0;

    distance=0;
    distance1=0;
    distance2=0;
}

readSensors.py

#!/usr/bin/env python
import serial as sr
import time
import sys

debug     = int(sys.argv[1])
sensorNum = str(sys.argv[2])
delay     = int(sys.argv[3])
 
if delay > 0 :
  time.sleep(delay)

port_serie = sr.Serial(port = "/dev/ttyUSB0", baudrate = "57600")
port_serie.setDTR(False)
time.sleep(0.1)
port_serie.setDTR(True)
port_serie.flushInput()

if debug == 1:
    print(port_serie.readline())
else: 
    val = port_serie.readline().split()
    if sensorNum == "sensor1":
        sensor = val[0]
    elif sensorNum == "sensor2":
        sensor = val[1]
    else: 
        sensor = val[2]

    print(int(float(sensor)))

port_serie.close()