CODEWITHSUNDEEP
pythonarduinoudp
Joe
Joe

Reputation: 135

Communication between Arduino and Python via UDP

I am struggling to build a communication bridge between Arduino and Python. Arduino should send an integer value to python. To enable the Udp communication I am using Ethernet shield 2 on Arduino and have to connect to IP "192.168.137.30". Now when I try to connect to bind with this Ip address, an error occurs because "192.168.137.30" is an external Ip address.

Below is my Arduino and python code :

#include <SPI.h>
#include <SD.h>
#include <Ethernet2.h>
#include <EthernetUdp2.h>         // UDP library from: [email protected] 12/30/2008

byte mac[] = {
  0xA8, 0x61, 0x0A, 0xAE, 0x2A, 0x12
};
IPAddress ip(192.168.137.30);

unsigned int localPort = 8880;      // local port to listen on

// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;


void setup()
{


  Ethernet.begin(mac, ip);
  Udp.begin(localPort);
  Serial.begin(115200);

  }

void loop()
{

   char  ReplyBuffer[] = "acknowledged";    
    Udp.beginPacket(ip, localPort);
    Udp.write(ReplyBuffer);
    Udp.endPacket();

}

Python :

import serial
import time 
import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(('192.168.137.30', 8880))
data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
sock.close()

I still can not send data from Arduino to Python. However, it is possible to send data from Python to Arduino. 

IPAddress ip(169, 254, 114, 130);
IPAddress my_PC_ip(169, 254, 94, 133);
unsigned int localPort = 7476; 
unsigned int pythonPort= 7000; 

void setup()
{
  Ethernet.begin(mac, ip);
  Udp.begin(localPort);
  Serial.begin(115200);

  }

void loop()
{
    Udp.beginPacket(my_PC_ip,pythonPort);
    Udp.print("hello");
    Udp.endPacket();
}

Python : import serial import time import socket

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(('169.254.94.133', 7000))
data, addr = sock.recvfrom(1024) # buffer size is 1024 bytes
sock.close()

Upvotes: 2

Views: 2974

Answers (1)

Joseph Sible-Reinstate Monica
Joseph Sible-Reinstate Monica

Reputation: 48632

You're not putting the right IP addresses in the right places. Here's what should be where:

  • In Ethernet.begin on the Arduino, you should use the Arduino's IP address.
  • In Udp.beginPacket on the Arduino, you should use your computer's IP address.
  • In sock.bind on your computer, you should use your computer's IP address.

You're currently using the same one in all three places, which doesn't make sense from a networking perspective.

Upvotes: 1

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