A02YYUW Ultrasonic distance Sensor (UART)

Projects Programming
1

I am using two ultrasonic distance sensor (A02YYUW) to measure distance. the output of sensor is UART. I have found this code which measures the distance for one sensor (A02YYUW Waterproof Ultrasonic Sensor Wiki - DFRobot).
It uses <SoftwareSerial.h> library. But this library has limitations that " * If using multiple software serial ports, only one can receive data at a time). and I need to use two sensors.
I am using Arduino Mega which have multiple serial ports.
Please support.

2

Hello

You don´t need the SoftwareSerial.h libary by using an Arduino Mega.

You can e.g. read and write to the UART like Serial1.read(); etc.

Have a nice day and enjoy coding in C++.

1 Like
3

The Mega2560 has 3 more hardware serial ports, Serial1, Serial2 and Serial3, Have a look at this pinout picture (bottom right, pins 14 ~ 19).
mega2.pdf (354.3 KB)

1 Like
4

Could you please support me with the modified the code.
The original code is :

/*
  *@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;

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

void loop()
{
    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)
          {
           Serial.print("distance=");
           Serial.print(distance/10);
           Serial.println("cm");
          }else 
             {
               Serial.println("Below the lower limit");
             }
      }else Serial.println("ERROR");
     }
     delay(100);
}
5

as others have said, you can use hardware serials 1,2, or 3
you can keep the software serial mySerial for your sensor1 then use Serial1 for sensor2

1 Like
6

Or, more sensibly, use hardware serial for all the sensors.

1 Like
7

There's a topic somewhere (possibly in the tutorial section) about robist handling of serial input.
It's well-worth a read.

8

I have an example sketch for the A02YYUW

A02YYUW Ultrasonic Sensor (Serial) (rothschopf.net)

The basic concept is based on "Serial Input Basics" Tutorial.

However - you can easily create two "Receiver Objects" and hand over different HW Serials when you create the object/instance.

First try to adopt the sketch for one HW Serial.
If this is working for you and you have problems to implement the second object/instance, post your code in code tags and come back to us.

9

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.