Raspberry Pi WIFI, remotely controlled vehicle

Hello, thanks to Ricardo Hernández, Oscar Canencia from AETEL and the Semana de la Ciencia robotics workshop in the E.U.I.T.Telecomunicaciones UPM, we manage to build a radio controlled car with webcam, driven with a PC via Wi-Fi. You will find an example in the next picture:

The code used to control the car from the PC (created with Python) goes like this:

#!/usr/bin/env python

# -*- coding: utf-8 -*-

#script inicial

#creacion: 01-11-12

#ultima modificacion: 03-11-12

#version:0.0.6

# File:client.py

import pygame

from pygame.locals import *

import socket # Import socket module

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Create a socket object

host = '192.168.2.1' #socket.gethostname() # Get local machine name

port = 5556 # Reserve a port for your service.

print 'Connecting to ', host, port

s.connect((host, port))

def sendcommand(tecla):

byte1 = chr(tecla)

#byte2 = chr(camera*8+laser_set*4+int(infrared_set)*2+int(light_set))

s.send(byte1)

opcion='y'

import msvcrt

print "press 'escape' to quit..."

while 1:

char = msvcrt.getch()

if char == chr(27):

break

print char,

if char == chr(97):

print "pulsó a"

sendcommand(97)

elif char == chr(119):

print "pulsó w"

sendcommand(119)

elif char == chr(115):

print "pulsó s"

sendcommand(115)

elif char == chr(100):

print "pulsó d"

sendcommand(100)

elif char == chr(112):

print "pulsó d"

sendcommand(112)

elif char == chr(113):

#cerrar la conexion y salir

print "Goodbye"

import sys

sys.exit(0)

Execute 2 ssh sessions, for control and video.

Command to load the server to control the vehicle:

sudo./server2.py

Código de server2:

#!/usr/bin/python

import socket # Import socket module

s = socket.socket() # Create a socket object

host = '' # Get local machine name

port = 5556 # Reserve a port for your service.

import serial

DEVICE = '/dev/ttyACM0' # the arduino serial interface (use dmesg when connectin$

BAUD = 9600

ser = serial.Serial(DEVICE, BAUD,timeout=1)

print 'Server started!'

print 'Waiting for clients...'

s.bind((host, port)) # Bind to the port

s.listen(5) # Now wait for client connection.

c, addr = s.accept() # Establish connection with client.

print 'Got connection from', addr

while True:

msg = c.recv(1) # get 2 bytes from the TCP connection

print 'Got connection from', msg

ser.write(msg) # write the 2 bytes to the serial interface

#mesg = ser.read()

#print 'respuesta', mesg

Command to load the video streaming server to get the vehicle view:

gst-launch -v v4l2src ! ffmpegcolorspace ! video/x-raw-yuv,width=320,height=240,framerate=(fraction)30/1 ! queue ! videorate ! video/x-raw-yuv,framerate=20/1 ! jpegenc ! multipartmux ! tcpserversink host=192.168.2.1 port=5000 sync=false

Configuracion el /etc/network/interfaces para configurar la configuracion wifi wlan0:

auto lo

iface lo inet loopback

iface eth0 inet static

address 192.168.1.100

netmask 255.255.255.0

gateway 192.168.1.1

auto wlan0

iface wlan0 inet static

address 192.168.2.1

netmask 255.255.255.0

gateway 192.168.2.2

wireless-channel 5

wireless-essid MYNETWORK

wireless-mode ad-hoc

iface default inet dhcp

Adjuntamos un video demostración: