Building An Internet Controlled Security Robot

contact: shelato at (add "Security Robot" to email subject line)

New! - Visual Basic Motion Detection Programming

Click here for project download

Third Generation

4 Wheel Drive Internet Controlled Rover

We've lowered the overall profile and given Turtle (or should it be Tiger), a new paint job.  We have also added a GPS unit.  The GPS feeds signals to the CUBLOC micro controller which sends the location back to the controlling pc on the internet.

Jump to File Downloads & Video Programming Lessons


Turtle In It's Charging Station

Copper tubes on whip antenna springs make contact with battery charger

  Control Panel (Visual Basic Express 2005)  

Youtube Movie Of Turtle Entering Garage


Turtle GPS - In French



Rover Plan

Solid Animation


Drive Components for Gen 3
click photo to enlarge
Drive Components for Gen 3


Second Generation Internet Robot Now Functional

Kids Electric Car


Kids Electric Car
Ebay $100
Camera & Guns
Axis 207M Camera
Camera & Guns
Electric Airsoft Guns

Linksys Router
Under the hood


Digital License Cubloc Micro Controller Camera View
Steering wheel visible

New File Downloads &

Video Lessons On Creating A Web Page To Control Your Microcontroller:

The Videos are all "wmv" files. Select From Pull Down Below.


Included in the videos above are video lessons on setting up a Linksys Router with DD-WRT firmware and creating a router bridge.

The Project:

Build a security robot that can be controlled and viewed over the internet.  The planned final version will be a kids 48" electric car with a network camera attached. The onboard Linksys router will transmit the camera and micro controller signals to a second Linksys router attached to the cable internet at the remote location.

1/4 Scale Trial Version:

I opted to try this out with a $20 RC car from Wal-Mart first, before I invest $200 in a kids car.


Linksys WRT54G Router - Used as the wireless connection from Bestbuy
Comfiletech: Industrial Micro Controller/PLC "Cubloc"- I'm using the industrial kit for all my projects, but you can purchase the parts separately: The Industrial Kit
Maxport: Ethernet to RS232 converter with web server.  Maxport   or Comfiletech Home Page
Kowasaki RC car from Wal-Mart
Camera: None yet.  The network camera draws about 2 amps at 12VDC.  When I scale up to the kids car I'll have enough power. 

David Shelato - Clemson University


Setting up the Router Bridge

See video lessons above for demonstration

This is the key to the project.  I needed the router to "bridge" to my home router, so it could act as the wireless modem.  While I could transmit directly from my laptop to the router on the car, my goal is to control a security robot via the internet.  In the video above, the laptop is talking to my home wireless router, not directly to the router on the car.    I've already tested it over the internet from a coffee shop.  The onboard router connects to the micro controller via the Maxport server, and will connect to a network camera in the future.

We purchased a $49 Linksys WRT54G router from Best Buy and flashed new DD-WRT firmware into the router. This is open source firmware that teaches the router new tricks, like bridging and significantly increasing the power. What a hassle though. It turns out the new routers have less memory than the old ones and several steps are required. The risk is turning your new router into a "brick". At any rate it worked. Here are the instructions:

Flashing a Linksys WRT54G with DD-WRT Firmware:

Note: If you are using a new Linksys Router, V.5 or higher, you will need to follow these special instructions to flash the new firmware because the new routers have less memory.

Setting Up The Bridge:

or Follow These Instructions:

Setting Your 2nd Router Up as a Bridge.

Connect to the router with an Ethernet Cable.  If your computer has a wireless connection to your primary router, turn off the wireless connection.  Otherwise, going to IP will take you to your primary router, not the one you want to work on.

Logon to the router that has been flashed with DD-WRT

From your browser go to

User: root

password: admin


Select Basic Settings from the top menu bar

Change Connection Type to Disable

Change STP to Disable

Change IP to

Check the Assign WAN to Switch check box

Change DHCP Server to Disable



Wait for the router to reboot, then log back on using


Select The Security Tab

Change SPI Firewall to Disable



Select Basic Settings Tab from Wireless Menu

Change Wireless Mode to Client Bridge

Change Wireless Net Mode to match your primary router.  For me it's Mixed

Enter the Name of your primary wireless router.  For me it's Home



Select Wireless Security

Security Mode - Match your primary router.  For me it's WEP

Encryption - Match your primary router.  For me, 64 bits

Enter the Key



Select Wireless Advanced Settings

Change Authentication to Shared Key



Select Wireless from the Status Tab

Click the Site Survey Bottom at the bottom of the page

Find your primary router and click the Join button at the right


That's it.  You are now bridged.  If your primary router is connected to the internet you should now be able to access the internet through the bridged router.



Port Forwarding

A few notes on port forwarding to the bridged router and Maxport

Link To Notes


Internet Interface

There are two components to the interface.  One a Visual basic program that sends and receives commands to the cubloc.  Two, the cubloc program that receives the commands, controls the cubloc and turns the outputs on and off.  The connection is:

Laptop===>Home Router===>Bridged Router---->Maxport---->Cubloc

===> Is Wireless
---> Is Wired

This is a screen shot of my test VB form.

This is a modification of the Zedomax Temperature form found at I modified the visual basic program to automatically connect to my router via it's IP address when the "Connect Button" is pressed.  The grid of buttons on the right send simple 4 digit commands to the car.  Buttons above the red square issue forward commands with an appropriate steering component.  Buttons below the red box issue reverse commands with appropriate steering signals.  For example, the button two positions above the red square and two positions to the right issues the command "F2R3".  Move forward for time 2 while steering to the right for time 3. 



LCD Display hangs in the passenger window.

On the test stand below.  The internet connection is wireless but I'm still connected to power supplies.

The Linksys router is shown in the driver compartment and the Cubloc controller is in the bed.

The fully load version on the test stand below.  It runs wireless!!!!!!!! 

The Maxport is sticking out the backend of truck connected to the Linksys router through the blue ethernet cable.  2 Green lights can been seen on the Cubloc.  The LCD display is in the passenger window.  The relays are in the back window of the truck.



The Wiring

The RC controls were completely removed from the car and discarded.  I simply cut the wires from the drive and steering motors and substituted an 8 relay board connected to the micro controller.  4 relays are used for each motor to swap the polarity.  I'm using (2) 9 volt batteries and a 12VDC voltage regulator to power the Linksys router (they probably won't last more than 30 min).  I'm using (3) 9vdc batteries to power the cubloc controller.  The motors are powered by the original 9 vdc rechargeable battery pack.


Click to enlarge

Cubloc Program

The micro controller program is very simple:

Const Device=cb280

 Set Ladder Off

 Set Display 2,0,0,128


Dim x As Integer
Dim a As String * 10
Dim TurnTime As Integer
Dim DirTime As Integer
Dim Dir As String
Dim Turn As String
Dim DirTimeStr As String * 1
Dim TurnTimeStr As String * 1

Opencom 1,115200,3,200,200     'Open Channel

Set Until 1,4

On Recv1 Gosub DATARECV                 ' JUMP to DATARECV_RTN when data is received

' Clear send/receive buffers

Bclr 0,2            


a = "OhMy"
TurnTime = 500  ' Turning Time

DirTime=1000  'Time forward or backwards
'Erase screen
Delay 100

Locate 2,0
Print "Internet Kow"
Locate 3,1
Print "By Shelato"
Locate 2,2
Print "January 2007"
Locate 0,3
Print "Wait" 


Delay 50
Locate 16,3
Print Dec x




If Blen(1,0) > 0 Then       ' if there is at least 1 byte in the buffer 

            a=Getstr(1,4)                 ' Get 1 byte
            'Debug a
            Delay 50
            Locate 0,3
             Bclr 1,0

            If Turn = "L" Then  'Activate relays for Left Turn  ' Make sure the relays are all off before switching poles

                        Out 41,0
                        Out 42,0
                        Out 40,1
                        Out 43,1

                                    Elseif Turn = "R" Then  'Activate relays for Right turn

                                    Out 40,0
                                    Out 43,0
                                    Out 41,1
                                    Out 42,1


                        If Dir = "F" Then  'Activate relays to move forward  ' Make sure the relays are all off before switching poles

                                    Out 45,0
                                    Out 46,0
                                    Out 44,1
                                    Out 47,1

                                              Elseif Dir = "R" Then 'Activate relays for reverse move

                                    Out 44,0
                                    Out 47,0
                                    Out 45,1
                                    Out 46,1


            Delay TurnTime   ' Make sure the relays are all off before switching poles

                        Out 40,0
                        Out 43,0
                        Out 41,0
                        Out 42,0

                                                Delay DirTime-TurnTime ' Make sure the relays are all off before switching poles

                                                Out 44,0
                                                Out 47,0
                                                Out 45,0
                                                Out 46,0



Print a



Visual Basic Program

Very Important Note:

You must add the MSWINSCK.ocx control to use the winsock functions in visual basic. Follow the simple instructions at this site: Link

One More Note: To add a Winsock component to the VB Express Toolbar, select Tools from the menu bar, then select Choose Menu Items, Click the COM tab, scroll down the list to Microsft Winsock Control, check the box and close it out.  Then go to the ToolBox and you will find the Winsock component at the bottom of the toolbox.

Again, this is a pretty simple modification to the zedomax temp program.  I only included a few of the buttons, as they are all the same with the exception of the 4 character command they send to the cubloc program:


Option Strict Off

Option Explicit On

Imports VB = Microsoft.VisualBasic

Friend Class frmMax

      Inherits System.Windows.Forms.Form

    Dim start As Integer

    Dim dcnt As Integer

      Private Sub frmMax_Load(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles MyBase.Load

            Text2.Text = ""

      End Sub

    Private Sub Command1_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs)

        If Winsock1.CtlState = MSWinsockLib.StateConstants.sckConnected Then Call Winsock1.SendData("Dwight")

    End Sub

      Private Sub Command2_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command2.Click

        If Winsock1.CtlState <> MSWinsockLib.StateConstants.sckClosed Then Winsock1.Close()

        Text1.Text = "" 'This is the default IP address of my router

            Winsock1.RemoteHost = Text1.Text

            Winsock1.RemotePort = 59004

            Winsock1.LocalPort = 0


        Mprint("Connecting to: " & Text1.Text & " Port: " & "59004")

      End Sub

      Private Sub Command3_Click(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Command3.Click

            If Winsock1.CtlState <> MSWinsockLib.StateConstants.sckClosed Then Winsock1.Close()


      End Sub

      Private Sub Winsock1_ConnectEvent(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles Winsock1.ConnectEvent


      End Sub

      Public Sub Winsock1_DataArrival(ByVal eventSender As System.Object, ByVal eventArgs As AxMSWinsockLib.DMSWinsockControlEvents_DataArrivalEvent) Handles Winsock1.DataArrival

        Dim rdata As String

        rdata = "whatever"

            If eventArgs.bytesTotal > 4 Then

                  Call Winsock1.GetData(rdata)

                  Text3.Text = rdata

            End If

      End Sub

      Sub Mprint(ByRef strm As String)

            Text2.SelectionStart = Len(Text2.Text)

            Text2.SelectedText = strm & vbCrLf


      End Sub

    Private Sub Text1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Text1.TextChanged

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

        If Winsock1.CtlState = MSWinsockLib.StateConstants.sckConnected Then Call Winsock1.SendData("F2R3")

    End Sub

    Private Sub Button12_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button12.Click

        If Winsock1.CtlState = MSWinsockLib.StateConstants.sckConnected Then Call Winsock1.SendData("R2L1")

    End Sub