TV Remote Controlled Robot using Arduino

What if you could control your robot wirelessly without making a remote or even buying one? Your TV remote which sits in your hands most of the time could do all controlling. Doesn’t that sound good? Well, it is quite easy to implement. Presented here is a Robot based on Arduino that can be controlled by a TV (or any IR Remote). so reader should have knowledge about start with arduino.

Prototype of TV Remote Controlled Arduino Robot

Fig. 1: Prototype of TV Remote Controlled Arduino Robot

Basically, the remote controls of electronic appliances be it TV, DVD, etc., work on IR communication principles. They transmit a code, in the form of IR pulses which is decoded by the receiver to carry out a specific operation. Each key is assigned a specific code based on a certain standard protocol developed by the manufacturer.

Image showing Arduino Circuit on TV Remote Controlled Robot

Fig. 2: Image showing Arduino Circuit on TV Remote Controlled Robot

A number of protocols have been developed till date by various manufacturers including Sony, Philips, etc. Some common and widely used protocols are Sony SIRC, Philips RC5/RC6, NEC, etc.

The code assigned to each key is nothing but a bit-stream denoting a train of pulses (High or Low) to be transmitted.

However, merely transmitting a bit-stream might not turn-out to be feasible because interference due to sunlight and other IR sources could affect the transmitted signal. To prevent this, the signal is modulated at a particular frequency, typically 36 or 38KHz. Thus, receiver must be capable of receipting a signal which is modulated at 38kHz.

Image showing chassis and wheels of TV Remote Controlled Arduino Robot

Fig. 3: Image showing chassis and wheels of TV Remote Controlled Arduino Robot

For the robot to detect commands of the remote, we need to decode the remote and place its commands in the Robot Controller (Arduino). This is done with the help of IR receiver, TSOP1738.

TSOP 1738

The TSOP is a miniaturized receiver for infrared remote control systems. PIN diode and preamplifier are assembled on lead frame, the epoxy package is designed as IR filter. The demodulated output signal can directly be decoded by a microprocessor. TSOP is the standard IR remote control receiver series, supporting all major transmission codes. Its output is Active Low.

Pin Diagram of TSOP1738 IR Receiver

Fig. 4: Pin Diagram of TSOP1738 IR Receiver

To know what signal is transmitted when a key on remote is pressed, we need to decode it. This can be done with the help of Oscilloscope which is difficult to find at home. Well an affordable solution to this problem lies in Arduino Library. “IRremote” library provides a ready code to decode the IR remote and display it on the serial monitor.

In Arduino IDE 1.0.5 and later, this comes pre-loaded, whereas for older version you can get the library from Arduino official website.

‘IRrecvDemo’ is a program to decode the IR signals. Get an Arduino and make connections as shown below:

Now upload the code ‘IRrecvDemo’ to the Arduino.

Screenshot of Arduino Code used for receiving IR signal by Robot

Fig. 5: Screenshot of Arduino Code used for receiving IR signal by Robot

After being done with uploading, open serial monitor window and point the remote you want to decode, towards the TSOP sensor.

Press any key. A code (Hexadecimal) will appear on window. Note down the code for further reference.

Repeat above step for 5 different keys, Forward; Backward; Left Turn; Right Turn; and Stop.

Now that we have the codes for each key, we now move further to create the Robot and upload the code to it.

Making the Robot

The robot is designed to have a 3 wheel drive, with its rear part by 2 Motors and front with the help of Castor wheel.

The Assembly of the robot can be user dependent. However Motor interfacing with Arduino is done with the help of H-bridge Dual Motor Driver IC (L293D) which is cheaper and easily available.

To receive the Remote commands, IR Receiver (TSOP1738) is also interfaced with Controller. The placement of sensor is on the top face of the robot, so that it can receive commands over a wide range.

Simple Block Diagram representation of the Robot is shown below:

Overview of TV Remote controlled Arduino Robot

Fig. 6: Overview of TV Remote controlled Arduino Robot

Assembly of the robot is shown below:

Representational Image of mechanical design of Robot

Fig. 7: Representational Image of mechanical design of Robot

Circuit Diagram (Decoding the Remote)

Circuit Diagram of Arduino based IR Remote Receiver

Fig. 8: Circuit Diagram of Arduino based IR Remote Receiver

Project Source Code

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#include <IRremote.h>
int RECV_PIN = 11;          // Output pin of TSOP sensor
IRrecv irrecv(RECV_PIN);
decode_results results;
void setup()
{
  pinMode(7,OUTPUT);
  pinMode(8,OUTPUT);
  pinMode(12,OUTPUT);
  pinMode(13,OUTPUT);
  irrecv.enableIRIn(); // Start the receiver
}
void loop()
{
   if (irrecv.decode(&results))
  {
   if((results.value)==0x1CE358A7)
     {
      stp();
     }
   if ((results.value)==0x1CE330CF)
       {
       fwd(); 
       }
  if ((results.value)==0x1CE3B04F)
       {
       back(); 
       }
  if ((results.value)==0x1CE3E817)
       {
       left(); 
        }
  if ((results.value)==0x1CE36897)
       {
       right(); 
       }
irrecv.resume();           // Receive the next value
}    
}
void fwd()          // function to move forward
{
  digitalWrite(7,HIGH);
  digitalWrite(13,HIGH);
  digitalWrite(8,LOW);
  digitalWrite(12,LOW);
}
void back()        // function to move backward
{
  digitalWrite(8,HIGH);
  digitalWrite(13,HIGH);
  digitalWrite(7,LOW);
  digitalWrite(13,LOW);
}
void left()        // function to turn left
{
  digitalWrite(7,HIGH);
  digitalWrite(13,LOW);
  digitalWrite(8,LOW);
  digitalWrite(12,LOW);
}
void right()        // function to turn right
{
  digitalWrite(7,LOW);
  digitalWrite(13,HIGH);
  digitalWrite(8,LOW);
  digitalWrite(12,LOW);
}
void stp()        // function to stop
{
  digitalWrite(7,LOW);
  digitalWrite(13,LOW);
  digitalWrite(8,LOW);
  digitalWrite(12,LOW);
}

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