Here I will show you how to make a cheap two-wheeled Arduino Bluetooth robot. You can make this toy robot using a PVC pipe and joints (for making the body). It is simple to make and easy to program. The robot is heaps of fun to play with and many more functions can be added to it. My design makes it unique and different from other Arduino Bluetooth robots. I made this toy robot not just for fun. I have plans to add an accelerometer, a camera, and some other small sensors to it. This will allow us to use this robot in various fields. This robot is only a basic design. My next plan is to upgrade this robot to v2.0 when I purchase the MPU 6050.

Pipe bot in action:

Potential applications:

Disaster management -

This robot has a simple design and only has two wheels and is a cylindrical shape therefore it can travel to almost all terrains and through dangerous areas.

Spying agent for military purpose -

This robot looks like a piece of PVC pipe there for no one can simply identify this as a robot since we can use this for taking images and for collecting information as a spying agent.

Home surveillance robot

Bluetooth application to control the pipe bot

Click here to download it

Parts required:

1. Arduino pro mini
2. L293d motor controller shield
3. Hc-06/05 Bluetooth module
4. FTDI parallel to serial converter
5. Arduino female pin socket
6. Perfboard
7. 2* 9-volt battery
8. 2* 9-volt battery clip
9. lM 7805 regulator IC
10. Heat sink
11. 2* Wheel
12. 2* Gear motor 100RPM

Body parts:

PVC pipe size - 1.5 inch(diameter)

1. 2 * Pipe pieces. Length - 56 mm
2. 2 * cup (closer). Length - 65 mm
3. 2 * coupling (double side joint). Length - 37 mm

Circuits and Electronics:

Make a shield for placing the Arduino board after roundly cutting the perf board. Solder the female and male pins to use the required pins of the Arduino. Try to cut the perf board and L293d module in a round shape, the same as the inner diameter of the PVC pipe. This will help to fit it inside the pipe and avoid wastage of space.

Insert the Arduino into the socket. Then connect the Bluetooth module, LM7805 regulator IC, and L293d motor controller as shown in the circuit diagram below. Now we can see that two cables are coming out of the board with 4 wires, these are going to be connected to the motor shield and the LEDs. I got the white cables from an old DVD player.

Wiring Instructions

Bluetooth module:

- "TX of Bluetooth Module" goes to "RX of Arduino"

- "RX of Bluetooth Module" goes to "TXof Arduino"

- "VCC of Bluetooth Module" goes to "5v of Arduino"

- "GND of Bluetooth Module" goes to "GND of Arduino"

- The State & Key pins of the BT modules are unused.

Motor controller:

- "C1-A of the motor controller" goes to "PIN 8 of Arduino"

- "C1-B of the motor controller" goes to "PIN 7 of Arduino"

- "C2-A of the motor controller" goes to "PIN 6 of Arduino"

- "C2-B of the motor controller" goes to "PIN 5 of Arduino"

LEDs:

http://www.instructables.com/id/Pipe-Bot-a-Smart-Arduino-Bluetooth-Robot/

- "Positive leg of red LEDs" goes to "PIN 10 of Arduino"

- "Positive leg of red LEDs" goes to "PIN 13 of Arduino"

Battery:

- "Positive Terminal of battery" goes to "+v input of lm7805 regulator IC "

- "Negative Terminal of battery" goes to "Ground pin of lm7805 regulator IC "

- "Ground pin of lm7805 regulator IC " goes to "GND of Arduino"

- "+v output pin of lm7805 regulator IC " goes to "RAW of Arduino"

Let's start drilling and make the body:

Make a large hole in the centre of each cap(closer). This is for placing the motors on each side. Also, drill 5 small holes around the periphery for placing the LEDs(use a 4.5mm drilling bit) as shown in the figure. After placing. connect the 5 red LEDs in parallel mode and solder them. Take the input wire for giving power to the LED set. Then connect the motor and screw it using the bolt.

Drill five holes for fixing LEDs around the pipe and insert the white LEDs. Connect them in parallel and take the power cable out. Do this for both the pipes.

As shown in the diagram on the right side, insert two 9V batteries(with clips) into one of the pipes and insert them into one end cap. From this site, you will have 5 pairs of supply wires coming out (end cap LEDs, pipe LEDs, motor and two batteries). Join this piece to the PVC coupler (middle piece) and take out all the wires from the open end as shown in the diagram. You have now completed one side of the toy robot. Now join the second PVC pipe to the other end cap and take out the 3 pairs of supply wires (end cap LEDs, Pipe LEDs and motor). The next step is to put in the electronics for the controller.

You can also use any other rechargeable batteries with/above 9 volts and 2 ah current (with the same size or less).

Connect the remaining cables with the LEDs. After connecting all white LEDs and red LEDs together, connect the board with the battery and let’s put the board facing the motor controller into one section(where the coupling is not included). In the last image we can see there is very little space on either side of the 9-volt battery and this is the place for the Bluetooth module and for the lm7805 regulator. Now we have completed the wiring of all electronic parts. The main thing to be noted here is that the space available inside the PVC is very small. So we have to utilize all the small spaces remaining after connecting the battery and motors inside the PVC pipes.

Programming the Robot:

And now, we need to program it. I am using the FTDI parallel to serial converter to program the Arduino pro. If you don’t have this converter, go through this tutorial to program our robot using Arduino UNO. (Don't forget to remove the Bluetooth module before programming)

The last step is to add a switch to the toy robot. Make a rectangular cut on the pipe in the size of your switch and hot glue it after making the connection. Stick all the pieces of PVC together and you will have something that looks like this.

Zap on the wheels to the motor shafts, switch on the LEDs and you are good to go!!