TCP/IP <=> Serial Gateway

I would like to comunicate with arduino via TCP simple command like (GO, STOP, LEFT, RIGHT, etc ... ). I would also like to receive from arduino messages from sensor values.

I have server.py - gateway TCP => ARDUINO => TCP

Code:

import socket
import serial
import time

def Main():
	host = '127.0.0.1'
	port = 5000
	arduino = serial.Serial('/dev/ttymxc3',9600)

	s = socket.socket()
	s.bind((host,port))

	s.listen(1)

	c, addr = s.accept()
	print 'CONN:  ' + str(addr)

	while True:
		data = c.recv(1024)
		if not data:
				break
		print "From user " +str(data)
		print "SEND ARDU: " +str(data)
		arduino.writeline(str(data))
	        time.sleep(5);
		print "READLN ARDU: "
		data = arduino.readline();
		print "sending " + str(data)
		c.send(data)
	c.close()
if __name__== '__main__':
	Main()

I have client.py to send commands and receive messages

Code:

import socket

def Main():
	host = '127.0.0.1'
	port = 5000

	s = socket.socket()
	s.connect((host,port))
	
	message = raw_input("=>")
	while message != "q":
		s.send(message)
		data = s.recv(1024)
		print "Received : " + str(data)
		message = raw_input("=>")
	s.close()
if __name__ == '__main__':
	Main()

I have serial.ino arduino serial request / response

Code:

String readString;

void setup(){

 Serial.begin(9600);
 Serial.write("Robot is powering On");
}


void loop()
{
 while (Serial.available()) {
    delay(3);  //delay to allow buffer to fill 
    if (Serial.available() >0) {
      char c = Serial.read();  //gets one byte from serial buffer
      readString += c; //makes the string readString
    } 
  }

if (readString.length() >0) {
      Serial.println("Dobil:"+readString); //see what was received
}
}   

I'm having trouble sending data from phyton to arduino (server frezes). What am i doing wrong ?

Regards,
Boris

 

Hi,

I'm sorry but I am no python guy and cannot answer your question. But I had the need for something similar, i.e. to be able to communicate with the arduino from a remote PC via TCP/IP. So maybe this is another approach that you could try.

I used the ser2net daemon which allows you to make a serial port available over tcp/ip on the UDOO. Then I could connect to the arduino serial port ttymxc3 via telnet from a remote computer or via sockets. It works like a charm.

sudo apt-get install ser2net

add to /etc/ser2net.conf

192.168.1.75,2000:raw:0:/dev/ttymxc3:115200 8DATABITS NONE 1STOPBIT banner

replace with your own values.

/etc/init.d/ser2net start

and from your remote just telnet to the ip adress and port. Then it is like you were sitting directly on the arduino serial port.

Maybe it doesn't answer your needs, but It is anotherway of doing it. Remeber to stop the daemon if you want to program the arduino from the IDE.

Good luck!

 

I'm not so good in python too but the codes seem right.
Did you upload your arduino sketch from the internal IDE of UDOO? 'cause i suggest to use simple byte or char instead of the "String" object of Arduino that sometimes causes strange communication issues if the sketch is compiled from the internal IDE.