How to read bytearray from arduino pin in arduino sketch

Question

I'm using the DYP-ME007TX sensor with arduino uno. The output from this sensor comes in packets of 4-bytes:

Data[0]= 0xFF: Packet Header
Data[1]= 0x0-0xFF: Data Most Significant Byte (MSB)
Data[2]= 0x0-0xFF: Data Least Significant Byte (LSB)
Data[3]= 0x0-0xFF: Data Checksum: = (0XFF + MSB + LSB) & 0xFF

Data is in MILLIMETERS

16 bit value in mm = Data[1] << 8 | Data[2]

How can exctract this packet in arduino sketch and extract millimeter number?

• Edgar Bonet: This is a serial data stream. Connect the device's OUT to your Arduino's RX, then read the documentation on the Serial library.
• Amon Olimov: I want to use two and more this kind of sensors, so I think I just can't use Arduino's TX. I used SoftwareSerial library: arduino.cc/en/Tutorial/TwoPortReceive

Answer 1

I found the answer from forum.arduino.cc There is a sketch

#include <SoftwareSerial.h>
// TX_PIN is not used by the sensor, since that the it only transmits!
#define PING_RX_PIN 6
#define PING_TX_PIN 7
SoftwareSerial mySerial(PING_RX_PIN, PING_TX_PIN);
long inches = 0, mili = 0;
byte mybuffer[4] = {0};
byte bitpos = 0;
void setup() {
 Serial.begin(9600);
 mySerial.begin(9600);
}
void loop() {
 bitpos = 0;
 while (mySerial.available()) {
 // the first byte is ALWAYS 0xFF and I'm not using the checksum (last byte)
 // if your print the mySerial.read() data as HEX until it is not available, you will get several measures for the distance (FF-XX-XX-XX-FF-YY-YY-YY-FF-...). I think that is some kind of internal buffer, so I'm only considering the first 4 bytes in the sequence (which I hope that are the most recent! :D )
 if (bitpos < 4) {
 mybuffer[bitpos++] = mySerial.read();
 } else break;
 }
 mySerial.flush(); // discard older values in the next read
 mili = mybuffer[1]<<8 | mybuffer[2]; // 0x-- : 0xb3b2 : 0xb1b0 : 0x--
 Serial.print("PING: ");
 Serial.print(mili/10);
 Serial.println("sm");
 delay(500);
}