Example Code for Arduino-Read Serial Port Data

Hardware Preparation

• DFRduino UNO R3 (or similar) x 1
• Multi USB/RS232/RS485/TTL Converter V2.0 x 1
• Water-proof Ultrasonic Sensor (ULA) x 1
• Connectors

Software Preparation

• Arduino IDE

Wiring Diagram

The internal probe surface is regarded as the detecting starting point by default. If you take the plane of the bell-mouth as starting point, then the distance will be the detected distance minus 40mm.

Sample Code

* **************************************************** 
* @brief Water-proof Ultrasonic Sensor (ULS)

 * @copyright	[DFRobot](https://www.dfrobot.com), 2016
 * @copyright	GNU Lesser General Public License

* @author [Xiaoyu]([email protected])
* @version  V1.0
* @date  2019-03-11
  
* GNU Lesser General Public License.
* All above must be included in any redistribution
* ****************************************************/

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); // RX, TX
char col;// For storing data read from the serialport
unsigned char buffer_RTT[7] = {};
unsigned char buffer_coderead[]{0xFF,0x01,0x01,0x01};
int Rage = 0;
float Temp = 0;
int Tflag = 0;
void setup() {
        Serial.begin(57600);     // Enable serial port and set band rate to 57600 bps
        mySerial.begin(9600);
        pinMode(LED_BUILTIN, OUTPUT);
        digitalWrite(LED_BUILTIN, HIGH);
}

void loop(){
         do{ 
           for (int j = 0; j <= 6; j++){
                col = mySerial.read();
                buffer_RTT[j] = (char)col;
                }      
        } while(mySerial.read() == 0xFF);
                mySerial.flush();
                if(buffer_RTT[0]==0xFF){//Judge the first bit of the data
                  int cor;
                  cor=buffer_RTT[0]+buffer_RTT[1]+buffer_RTT[2]+buffer_RTT[3]+buffer_RTT[4]+buffer_RTT[5];
                  cor=cor&0x00FF;
                  if(buffer_RTT[6]==cor)
                  {                     
                  Rage = (buffer_RTT[2] << 8) + buffer_RTT[3];
                  Tflag=  buffer_RTT[4]&0x80;
                  if(Tflag==0x80){
                  buffer_RTT[4]=buffer_RTT[4]^0x80;  
                  }
                  Temp = (buffer_RTT[4] << 8) + buffer_RTT[5];
                  Temp = Temp/10;
                  }
                  else{
                    Rage = 0;
                    Temp = 0;
                     }
                 }  
                Serial.print("Rage : ");
                Serial.print(Rage);//Output distance unit mm
                Serial.println("mm");
                Serial.print("Temperature: ");
                if(Tflag ==0x80)
                {
                  Serial.print("-");           
                }
                Serial.print(Temp);//Output temperature
                Serial.println("℃");
                Serial.println("============================== ");  
                delay(100);       
        }                

Result